EPC Q & A REVISTITED

EPC Q & A REVISTITED

Of late, Vag vehicle owners are experiencing Electronic Power Control problems more frequently than ever before yet most VW, Audi, Skoda and Seat still have no idea what an EPC fault is and what causes the EPC light to turn on. To add insult to injury some VW, Audi, Skoda and Seat service agents tend to "repair" these faults by trial and error, costing the vehicle owners exorbitant amounts of money only to later discover that the fault persists. The EPC warning light can be found in selected models in virtually all makes of cars and is not limited to just Volkswagen Audi, Skoda and Seat vehicles. Volkswagen Audi, Skoda and Seat use Electronic Power Control in their drive by wire vehicles as a safety feature which in my opinion isn't all that safe. Case in point, I have had my VW Polo go into limp mode whilst overtaking a car in a two way street.  It stalled at the very moment when I was cutting-in in front of the said car, causing its driver to frantically brake and swerve to avoid colliding with the rear of my car because  suddenly I wasn't accelerating any longer. Not to mention the on-coming car, which swerved toward the shoulder of the road since my car was straddling the white line. My EPC problem turned out to be the incorrect octane fuel.

Be that as it may, by the time the EPC light illuminates in the dashboard, in response to some sensor detecting a problem, the problem already occurred in either the torque control, traction control, throttle body and sensors, accelerator pedal sensors, cruise control,  fuel supply or ignition systems. Essentially the epc light is just a way to tell you that there is a problem with the drive by wire system and generally remain on until the fault is cleared.  At the instant that the EPC light illuminates, the  ECU flags a DTC which is then stored in the relevant electronic control module. This DTC gives a fair idea of the suspect system but cannot pinpoint  the culprit component. 

QUESTION?

Anonymous says:- Hey I have a 06 Passat 2.0t and I am reading all of these stories on the EPC my check engine light was already on while I was driving but the car was good. I was on my way to work after stopping at the gas station and my EPC light came on and my car stalled on the highway and has not came back on. The lights windows and everything works but when I try to turn the car on it attempts to turn but never does. 

ANSWER!

From your description I understand that after your EPC light came on, your car won't restart. So you checked the light and windows which tells me you suspected that the battery may have run down and perhaps not strong enough to turn the engine over.  But you also mentioning 'check engine light'. A combination of check engine light and EPC light is emissions related and if your car's emissions exceed a predetermined level, the ECU will prevent the engine from starting. Its best that you have your car scanned to see what DTC it threw out. 

QUESTION?

Musa Brain says:- Hi there. I have a VW polo vivo I have the EPC light on when I'm driving slowly and also when I'm reaching a stop sign and hit the clutch pedal it turns off and when I start it in the morning it turns off so I have to rev it for it to idle but after some few minutes the EPC light comes on. Please help?

ANSWER!

Musa your description of your EPC problem seems that you car doesn't idle fast enough. I assume that its drives normal whiles on a higher rev. It quite evident that it switches off when you come to a halt and whilst it's cold. I suspect that you have a blocked air filter problem that doesn't allow sufficient air to the MAF, but I could be wrong since you provide no DTC's. It could also be a blocked fuel filter that starves stichiometricity since torque is determined by both  air and fuel. 

QUESTION?

Bogdan Iova says:- When I swich key on the EPC light not apear and teh engine not start. Golf 1.6 16V 

ANSWER!

Bogdan, you really haven't given me much to work with here, but off hand it seems that you may have a blown fuse that powers the instrument cluster. Because the moment you turn on the ignition key, the OBD II system does a self  diagnosis by turning on all the dash board lights for about 10 seconds whilst running the test.  It then turns off  those light related to the circuits that function normally and leaves those lights on, for circuits that fail the test.  So, if you EPC light does come on when you turn on the ignition , then goes off,  you don't have an EPC problem.   However if your engine won't start it's obviously cause by something else. It could be that your battery has reached end of life. If the engine doesn't turn over, even the starter could have packed-up. But if it does crank and won't start, check your fuel gauge to at least determine that you have fuel in the tank.  Related to this could be your ECM Power Relay, your fuel pump relay or the fuel pump itself. Without more info, this is about all I can help you with. DTC codes would have been helpful.

QUESTION?

Anonymous says:- Hi there, I have a 2003 polo 1.6, EPC light is on and when it's idling can't rev it, checked and cleaned the throttle body and still same issue, ran a diagnostics check and it says something about the pedal, please help?  

ANSWER!

Hi Anonymous, you seem to have a classic EPC problem but for the benefit of everyone else, it would have been great to share the DTC codes that you recovered. I suspect it must have been one of the following codes since you mention the error code said something about the accelerator pedal.

18038  P1630 Accel, Pedal Position -G79 signal too small  (low)
18039  P1631 Accel, Pedal Position -G79 signal too largely (high)
18040  P1632 Accel, Pedal Position -G79 supply voltage  malfunction

18041  P1633 Accel, Pedal Position -G185 signal too small
18042  P1634 Accel, Pedal Position -G185 signal too largely
18047  P1639 Accel, Pedal Position -G79 & -G185 out of range 

You also mentioned that you checked and cleaned the throttle body. If you dismantled it in anyway, then you need to redo adaptation, else the ECU would have no idea how wide the butterfly valve has opened.  Remember there is no throttle cable connecting the accelerator pedal to the throttle housing. This is known as a drive by wire system and it communicates the driver's torque demand to the ECU. The two potentiometers in the accelerator pedal assembly communicates the pedal position directly to the engine control module (ECM) using two separate signals, one signaling the pedal physical position and the other indicating rate of pedal movement.  You will need a scan tool to do the adaptation because any faults in memory must be cleared before adaptation can be done. 

The most common problem is the accelerator pedal itself. One or both of the potentiometers go high resistive/ intermittent and the accelerator pedal assembly should be replaced as a single unit. A tell tail sign of accelerator pedal trouble is that the engine revs higher than 800 rpm and at times the rev counter rises and falls continually whist idling, going as as high as 2000  rpm. If this happens, grab hold of the pedal whilst the car is idling and pull the pedal upwards, away from the floor. If the revs reduce and the surging stabilizers, replace the pedal. The image above shows idling whilst engine in surging and  the image below shows idling with the pedal pulled up.

DOOR LOCK PROBLEM ON POLO 9N

DOOR LOCK PROBLEM ON POLO 9N

For the past week or so, I've noticed some peculiarity  with my VW Polo's left side  front passenger door locking mechanism. To risk stating the obvious, my VW Polo is a right hand drive car. Its auto lock feature is enabled, so when I drive and reach about 15 kmph all the doors lock simultaneously and the sound made by the four solenoids are clearly audible when this happens. But then, the front passenger door immediately unlocks itself. Initially it was the sound of the solenoid in the left passenger door that alerted me to the fact that it locks then unlocks itself.  

Physically, all four door buttons/knobs  are retracted at 15 kmph, three stays down but the left front passenger door buttons/knobs pops back up again. After this happened a few times,  I re-locked it  by pressing the internal central locking button on the driver's door panel. The left passenger door responded to the central locking lock instruction by re-locking but then immediately unlocks itself again. It just doesn't seem to want to stay down.

Thinking that it was just an electronic glitch and that the door might still be locked, even if the button jumps up. So I stopped the car, rolled down the left passenger window, climbed over the console, stuck my hand outside and pulled on the door catch. Surprise, surprise the door opened.  So I thought to myself, this isn't good, in fact it really sucks.  It's a huge safety risk driving with an unlocked door, especially considering the amount of bag snatching and car hijacking that's been taking place of late. 

Thieves and criminals hanging out at stop signs and at a traffic lights patiently await the opportunity of an unlocked door coming their way, so that they can jump into your vehicle and rob you. I know of a case when three villains jumped into a nurse's car and forced her at knife point to drive to an ATM, to withdraw her daily cash limit. They then held her hostage until after 12:00 the evening just so that they could get the balance of her money from her account which was less than her daily limit for the next day. Fortunately they didn't harm her, but her nerves were totally shattered.   Anyway, what I discovered much late is that when the passenger door button/knob pops up and I can manually press it down, and it doesn't pop up thereafter and the door stays locked.

Anyway, this door button/knob popping-up  started to irk me and it was getting flippen irritating, so one afternoon when I got home from work, I decided to tackle the problem. I switched off the engine, removed the key from the ignition, and all the doors unlocked simultaneously, which is absolutely normal.  So I re-locked the car with the fob remote key and all the buttons stayed down as they should. When I depressed the fob remote key unlock-button twice in quick succession, and all the doors unlocked which is also perfectly normal. From this I deduced that the electronic circuit responsible for unlocking the passenger door must get its power via the ignition switch, since it only unlocks when driving at 15 kmph and not whiles it's stationary and therefore  there has to be a dedicated switch in each door. 

But before I start taking things apart I needed to make absolutely sure that the problem is in the left front passenger door.  I once again used the fob remote key to lock  all the doors to make sure that they stayed locked, which they did. When I unlocked the Polo with the fob remote key, only the driver's door unlocks which is perfectly normal. But within 3 seconds the left passenger door also unlocks, and that's not normal. So I realized the problem is specific to the left passenger door yet I needed to make absolutely sure.

Sitting in the drivers seat, I  turned on the ignition and opened the drivers door and saw the  red light, door-open icon in the dashboard instrument cluster turn on. I repeated this process on the front passenger and rear doors, as well as the boot lid, all of which activated  the red door-open icon except the left front passenger door. The next test was observing the interior light. As I opened the driver's door to get in, the interior light turned on, so I waited for the light to automatically turn off. I then reopened the door and the light turned on as it should. I repeated this action on the other doors which also worked as they should, except the front passenger door that didn't register that it was opened because the interior light stayed off.  

From this I deduced that both  the instrument cluster door-open icon and the interior light is powered from the same switch in the door which is actually  intermittent when not short circuit. Then I got out my laptop and my VCDS cable, rigged it up and Voila! With the all the doors wide open, as can be seen in the image below, the passenger door switch remained closed.

As can be seen in the above image, with all four doors open, the  software
still sees the passenger door is closed

As can be seen in these images the door and trunk Measuring Value Blocks are 005, 006 and 007. With all the doors closed, as can be seen in the images below,  the state of the passenger door switch didn't changes at all. So just for the hell of it, I banged the passenger door a few times hoping that the switch would budge because I'm certain it was stuck in place rather than the contacts burnt together. 

Now that the preliminaries are out of the way,  I can finally get out the screw drivers, spanners and the torx wrench and dismantle that pesky door mechanism. The following pics gives a fairly good idea of what it entails to remove the door lock; and on a scale of 1 to 10 with 10 being the most difficult I give it a 7. Removing and replacing the steel trace link that fits between the exterior handle and the lock is quite a challenge if you  have large hands. 

The door panel before dismantling it

The plastic cover removed to expose the screws.

Removing door handle screw with hex key

The inside view of the door panel with the electric window plug unplugged

The slide mechanism mounting plate with all its screws removed

Removing the torx screws that secure the door lock

The sliding window removed from its clamps and stored safely

Screws of the backing pate, the inside door handle, 
the door lock and the inside door lever

The passenger door lock with the micro switch dangling on its blue and red wires

I sprayed the the micro switch with some Q20 multipurpose lubricant  and flicked it a number of times. I also cleaned the the metal pawl that activates the micro switch. It has a little notch in it, that fills up with grime. I suspect it is this grime and plastic burrs that cause the micro switch to misbehave.  I used two straight pins to pierce the insulation of the micro switch wires in order to connect my Fluke multi-meter so that I could do a continuity tests.

Continuity measurement of the micro switch in its normally open position 

Continuity measurement with the micro switch depressed -closed position.

The steel trace link between  the outside door handle and the lock.  It is 
quite difficult to remove and put back especially if you have large hands.

The door lock "question mark looking" lever, is where the 
short steel trace cable links into

The steel trace must be held in the horizontal  position before it can 
be inserted  into place.

Showing the steel trace link in place, but it has to inserted during 
assembly when the lock in secured to  the door frame.

Several other VW Polo owners have had similar problems with one or more of their doors. For example: When you lock the car with the inside central locking button, the left hand side passenger door does not open when it is unlocked, so the driver has to roll down the window an open it from the outside. I clearly remember that both my Golf 1 and Golf 2 had door lock issues and a replacement lock was really cheap. In fact it was less that the price as a pack of 30 cigarettes. But times have changes and considering the replacement cost of a VW Polo door mechanism (R900 -R1200 excluding labour) and what a shitty job it is to replace it, most drivers just learn  to live with it.  The nature of VW central locking issue can range  from mechanical to electronic, from a sticky micro switch, to cracked/dry solder joints on the printed circuit board. Sometimes  grime / builds -up between the micro switch and its activator, so give it a good clean and spraying the micro switch would be wise once the relevant lock has been removed. 

I know of a VW Pasat that had a similar issues. When the car is unlocked with the fob key neither of the inside nor the outside handles would open the door and since the door needs to be open to repair/ remove  the lock, the car eventually had to go to the agents who charge a whopping R5500.00 to fix it. At least if the other doors had a keyhole to open them, it would have been so much easier. But it is all about cost saving for manufacturers.

Other issues

Central Locking, central locking problem, doors unlock, doors will automatically lock, remote key entry to unlock all the doors, remote unlocking, dealing with locking unlocking issues, can open the door from outside nor inside, remote not working on left passenger door, front passenger door immediately unlocks itself, door unlocks automatically, Doors lock with fob key  then unlock themselves, it locks and then unlocks,

BRAKE PAD REPLACEMENT

BRAKE PAD REPLACEMENT

Wear and tear on any car is expected and is a natural part of everyday motoring. In most cases when a car goes to the VW service agents for a service, they will often advise on the condition of the brakes pads but very seldom if ever replace them. So it is very likely that your car's brakes pads may reach end of life somewhere between services. This means that you either have to take it back to the service agents for them to replace your vehicles brake pads and that at an exorbitant cost or you do it yourself. Considering that break pads are very straight forward to replace and can be done within and hour. Here I'm referring to the front brake pads. It is also very unlikely that all four brake pads will require replacement at the same time. On a level of 1 to 10 where 10 is the most difficult, Brake pad replacement weighs in at around 3. If you can change a tyre you should be able to replace your own car's brake pads because it has less than half the amount of bolts of one wheel. 

On my VW Polo 2.0L Highline each brake caliper is secured with only 2 bolts and I'm almost sure that goes for most other VW, Audi, Skoda and Seat vehicles too. The tools required is a 18 mm socket and a power bar, a jack, 2 jack stands and a wheel brace. Ok, perhaps a large hefty screwdriver with which to prize open the brake piston completely. 

The brake pad wear light is clearly visible right in the center of  the instrument cluster.

When my dash light came on I knew I only had 2 mm of brake lining left because the last time I fooled around with my VCDS software and my "Dual-K plus CAN interface cable", I specifically selected 2 mm before the warning is sounded. Anyway when the brake pad replacement light went on, I made my way to the VW service agents to get a set of brake pads because I was going to replace them myself.  As can be seen in the image below the brakes are genuine Volkswagen Brake pads made in India for VW, SEAT, and SKODA. 

Genuine Volkswagen  Brake Pads for 2.0L vehicles

The incorrect brake pads for a VW Polo 2.0L Highline

They weren't too expensive and considering what they do, they are actually worth every cent. The spares agent supplied the "correct brake pads" for a VW Polo 2.0L Highline and when I opened the box back home, I was convince they were the ones I needed because the brake pad box listed several other 2.0L VW vehicles amonst which are New Beetle / Cabrio 1998 - ...., Bora / Variant / 4 Motion 1997 - ..., Caddy 2004 - ..., Golf / Variant / 4 Motion 1997 - ..., Golf Plus 2005 - ..., Jetta 2005 - ..., Polo 2001 - ..., Polo Limousine (Stufenheck) 1996 - ..., Seat Altea 2004 - ..., Seat Ibiza 2002 - ..., Seat Leon 2000 - ..., Seat Toledo 1999 - ..., Skoda Fabia 2000 - ..., Skoda Roomster 2005 - ..., Skoda Octavia 1999 - ...  

I was always under the impression that the Skoda Octavia was the same as a VW Polo GTI hence I figured the brakes were the correct ones but I was mistaken. As luck would have it, when I stripped out the worn front brake pads  they were completely different from the  the new brake pads that I just bought. 

Worn brake pads with slightly less than 2 mm of bonding left.

So off I went back to the agents to get the correct brake pads. Unfortunately they didn't have any  so I had to get an OEM set elsewhere.  After much shopping around, I eventually found the correct ones made by Vika. They were an exact match to my sample brake pad.

The correct brake pads after the exchange

The correct Brake Pads for the VW Polo 2.0L highline

The correct brake pads with the sensor connector in the foreground

The three pads without brake pad thickness sensors.

Now that the I had the correct pads, I cleaned out the excess dust, squirted a bit of molyslip synthetic grease into the spring clips where the two little wings of the brake pad slides in, and fitted the new brake pads in like 45 minutes.  I connected the brake pad sensor plug and I made doubly sure that I torqued the bolts securing the calipers. I pumped the brake pedal a few times to make certain that the pistons advanced against the  brake pads and I even topped-up the brake fluid. After replacing the wheels, I was back on the road in a jiffy. It took me way longer to go buy and exchange the correct pads than it took to actually fit them.

The worn brake pad before it was removed

The caliper removed with excess dust removed.

The brake pad piston fully retracted with the anti rotating plate in place.

Resting the Caliper on top of the disc is quite convenient to fit the brake pads

The 2 new brake pads positioned in their grooved spring clips with sensor wire visible

New brake pads after it was fitted 

The new brake pad is clearly visible through the vent in the caliper

EPC Q & A

EPC Q & A

So many Audi, VW, SKODA and SEAT owner are having EPC light nightmares. Sending their vehicles for EPC repair which are often misdiagnosed, costly, ineffective and futile because most mechanical repair personal are not electronically trained hence have no idea of  digital logic and isolation procedures.  Modern cars are strewn with sensors and actuators, network buses, electronic control modules driven by software. To quote a line in Turks and Caicos which goes something like this "... everything changes. I used to be able to take a wrench and get under my car's bonnet and fix my car. Now you need a degree in electronics. Even easy things are difficult now." Replacing automotive components does not have to turn into a 'wild goose chase' where guess work is based on trial and error which now has become the order of the day.  That approach just scares everyone. Upload the diagnostic scan of your car now, so that I can analyse for you before you go ahead and buy expensive parts only to find out that the DTC was incorrectly interpreted.

Question?

I'm Lorraine from long beach. I don't know who you are but you are a God to me. I've been searching the web for months for specific and in-depth information on the "death light" (EPC) appearing on my '99 Volkswagen  Beetle. I have studied your entire blog and will now have a very interesting conversation with my German Car mechanic on how he can detect once and for all the problem. Already $1,000 in with no results. Thank you. I hope I don't have to sell the car just yet (to whom, I have no idea) throttle body replaced-twice so far-but hmm that Cam Bus section is interesting. My radio went into Safe Mode months ago and then spontaneously came back on (we do not have the code) so maybe we should check that path out as well. Again thank you.

Answer!

Hi Lorraine, since you don't say much about the specific problem that you are having other than the "death light" (EPC) appearing on my '99 Beetle, I really can't comment on it. However since it is EPC related, your problem has something to do with fuel delivery and engine torque electronics. Bear in mind that your fuel is under pressure from the tank to the injectors and that the ECU receives inputs from the various pressure sensors. If any of these pressures are below spec, it can trigger an EPC problem. For example, if your fuel cap does not seal properly the low fuel pressure sensor G410 will send a error signal to the ECU which can trigger an EPC fault. Likewise if the fuel regulator sensor cannot equilize the fuel pressure from the high-pressure fuel system it will trigger an EPC fault. Suppose If you were driving on an incline like an on-ramp to a bridge and didn't gear down sufficiently for you Beetle to swiftly climb with ease, the likely hood is that detonation would occur. If this happens, the knock sensors would inform the ECU which translate detonation as insufficient torque and trigger the EPC circuit - limp mode and EPC light. There are several other EPC possibilities but without a diagnostic scan it is difficult to pin point the problem.

Question?

Anonymous. I have a '07 Polo 1.4 16v BUD. I don't have any lights on the dash, but the engine seems really weak through mid revs and is using a bit too much fuel. When I hook up my OBDII there are no faults recorded but when i view the throttle position in real time it doesn't seem to open in a linear manner. As I press the pedal on the road, the throttle valve seems to open slower than the position of the pedal. eg; 50% pedal = 30% throttle position, 80% pedal = 35% throttle, 95% pedal = 40% throttle, 100% Pedal = 100% throttle. As you can see WOT does give WOT at the throttle body, but I don't generally drive with my foot planted on the floor. I am confused why it does this as you would expect the throttle body to open the same amount as the pedal, could it need alignment? I am loathed to take it to the VW dealer for fault diagno$i$ so if anyone has any ideas???? Thanks

Answer!

Hi there. Since you don't have  diagnostic scan its difficult to help you however, the mere fact that you don't have dash light makes it very obviously that you have electrical problems or wiring harness problems. And since your scan tool didn't find any DTCs, further proves that this is the case. The dashboard is normally directly connected to the OBD port in the driver's cockpit and since you have no dash lights you most likely have missing voltages on the OBD port which is most likely needed to perform a proper and correct diagnostic scan. Check your fuses on the terminal 30 line and the relay that supplies the terminal 15  supply line. Once you've exhausted everything else, as a last resort your dash control module could be faulty. Anyway, the acceleration peculiarity that you are describing probably has nothing to do with the dash electronics. Since you car has drive by wire, which is totally electronic (not throttle cable), torque is determined by the ECU which will open the throttle valve logarithmically based on its load and terrain, thus there is no physical correlation between the accelerator pedal and the throttle valve. So, no I don't think it needs alignment but seeing you have an OBD-II scanner, its quite simple for you to just redo the adaptation (described in a previous blog) and take consolation in the fact that you have eliminated it as a problem.

Question?

Hi I have a problem with EPC it came on since yesterday, am worried please help.

Answer!

My friend, you really not giving me much to work with here. But I suggest that read through my blogs pages related to EPC, torque, drive by wire, accelerator pedal sensors, knock sensors,  throttle adaptation, engine RPM sensor, etc. Perhaps if would shed some light on your EPC problem. Remember that EPC problems are related to what the car was doing at the time the light came on. for example, spirited driving / towing / start stop peak hour traffic, etc, Anyway the best way to find blog pages relating to your EPC problem , is to type your search word (EPC / drive by wire, etc) in the search box I provided in the top left hand corner on the first page of my site and click on the miniature magnifying glass to run the search. Happy searching.

Question?

Hi everyone, I would really appreciate some advice from you all. I have a 2002 (52) Ibiza 1.4 Sport (100bph), and have some issues with it. Background: Since day 1 it has occasionally thrown up an EPC warning light, followed by an engine electrics light. They would go away after a day and not return for several months. I had the logs read by a Seat dealer during a service and they said it had shown an intermittent Lambda filter error, and that it would cost £240+ to fit a new one. I passed. Over the last month, this has become an every day occurrence. The EPC light will come on seemingly as I just try to pull away from stationary. The car sometimes (half the time) notably stutters when this happens, then pulls away normally. If I restart the engine, most times the EPC light will go off, but the engine light will stay on. Then, more weirdly, the car has started occasionally stalling at random. No judder, no rough idling, I'll be slowing down towards a roundabout or into traffic, and whilst idling (coasting on the clutch) as I slow down, I'll notice the battery light come on, and the power drop out. Once, the battery light came on, but I was able to rev the engine up and it recovered - the battery light then went out. Mostly, I need to restart the engine though. I took it to a garage called Vee Ws for its annual service yesterday and asked them to look into it as well. They went with a cautious (on my finances) approach, and said they'd do the full service and that hopefully that on its own might rectify some of the issues. After the service, they said the logs showed some intermittent issues but nothing serious. They reset the onboard computer to its basic/default settings and said they hoped that would sort it. They also said they noticed the throttle body was pretty dirty (done 71,000 miles), and that if the service doesn't sort it, that they would try to clean that up and see if it did the job. Anyway, 10 minutes after I pulled away from the garage, the lights came back on and today the stalling re-occurred. I feel like this could turn into one of those 'wild goose chases' where its a case of trial and error, replacing different parts to see if it works. This scares me greatly! Has anyone experienced any similar symptoms, or would anyone recommend going to a proper Seat Dealership/Services team to take a look? I wonder if maybe they may be more likely to find the underlying fault? Having said that, I've always found Vee Ws in Bristolonia competent and most importantly, cost-effective. It may be possible to ask them to try and source used-parts while they try different 'fixes'.. Thanks for any advice, Jamie

Answer!

Hi Jamie,  the fact that your SEAT occasionally throws up an EPC warning light, as well as  the engine electrics light, says that your problem is more likely emission related, hence your intermittent Lambda error. Normally only torque and fuel related problems triggers the EPC light, meaning the engine light doesn't come on. Engine light only comes on with emission related issues.  Considering the age of your car it is possible that the Oxygen censor could be glazed over (end of life) or its wiring connector could be intermittent. The oxygen sensor is a feedback mechanism that instructs the ECU to increase or decrease the fuel supply hence shuddering. But this may not be definite. Without a diagnostic scan, I  am more inclined to say it could be your throttle body sensors not only because your service agent said it was dirty but because of the stalling and stutters on pull away. This seems like the throttle valve isn't providing an adequate air supply when its needed. However if they serviced your SEAT and did the adaptation as they said they did, then its unlikely the throttle body else adaptation would have failed, even though they said its dirty. So its more likely to be your accelerator pedal sensors. I mention this because  the car switches off when you decelerate, implying while your foot was on the accelerator it was OK but by taking your foot off the accelerator the condition changed and the ECU picked of this which could be due to 1 or both intermittent potentiometers. When you initially start the car  the ECU does a self-test by switching on all dashboard lights and if no problems are detected turns them all off. So when you start and the EPC light turns off, at that specific point in time there is no problem, but half way through acceleration while driving the problem is detected and the ECU switches he car off. Intermittent DTCs that do not reoccur during four driving cycles, are automatically deleted from the system which explains why the EPC light goes out after a day or so and doesn't show up months later. Lets have a diagnostic scan and I will have another crack at analyzing your problem.

INTERNAL CONTROL MODULE MEMORY ERROR

INTERNAL CONTROL MODULE MEMORY ERROR

DTC error 65535 (Internal Control Module Memory Error) suggests a problem was caused  within the said module. However, Electronic Control Modules are generally fairly robust and are designed with a MTBF of 1 million hours. My experience with electronic repairs over the past 30 years does not confirm this since I have had tons of electronic components failing during this time that was'nt expected to fail for at least another 10 years. Be that as it may, an Internal Control Module Memory Error may not even be caused by the module, so it should be the last component to suspect and replace because they are normally not cheap. Firstly check the battery Supply Voltage  and verify that it is constantly about 12V or higher. Also make sure that the alternator is charging, since a faulty alternator can lead to a slowly discharging battery not able to supply the minimum voltage required by the module that is flagging the  65535. Next check to wiring harness to and from the "faulty" Control Module. Make certain that the module has a ground connection (earth). If  VCDS displays an unexpected result or displays that the controller refused the command, it is most likely due to the wiring. Under intermittent wiring conditions it is generally difficult ifnot possible  to clear a  65535 (00-10) or (35-00) or (35-10) or (37-10). Wiring harness and its connectors are prone to corrosion due to condensation especially in cold weather. If needs be, unplug the connector and clean them and if possible check the physical contact with an ohm meter (but disconnect the battery first). Any Internal Control Module Memory Error associated with the Power steering  and ABS are critical and should be attended to immediately. Internal Control Module Memory Error associated with Airbags should be treated with caution since interrogation of the airbag with a scan tool could inadvertently trigger the airbag or turn on the airbag light which can only be switched off by replacing the airbag module. As can be seen below, virtually every electronic module can be a victim of 65535 - Internal Control Module Memory Error and as far as I am concerned, it most unlikely electronic design and quality control  will permit such modules to be installed in production units. The lateral acceleration sensor tend to cause an 65535 airbag error, the vacuum hose inside the ECU taking pressure to the barometric sensor tends to cause a 65535 error in Jetta's, barometric sensor itself tends to cause 65535 in Skodas.  As a last resort try replacing the module concerned.

Address 01: Engine
Chassis Type: 17 - VW Golf Citi
Part No: 6KS 906 258 k
Component: 1.4 MP9.0 26ZA0003
Shop #: 2227355880
65535 - Internal Control Module Memory Error

Address 02: Auto Trans
Chassis Type: 9M - VW Jetta IV
Control Module Part Number: 01M 927 733 KT
Component: AG4 Getriebe 01M 4891
Software Coding: 00000
Work Shop Code: WSC 00000
65535 - Internal Control Module Memory Error

Address 03: ABS Brakes
Chassis Type: 6Y - Skoda Fabia I
Part No: 6Q0 907 379 D
Component: ABS/ASR 5.7 FRONT V00
Coding: 00124
Shop #: WSC 13765
65535 - Internal Control Module Memory Error 

Address 03: ABS Brakes
Chassis Type: 1J - VW G/J/B Mk4
Part No: 1J0 907 379 AB
Component: ESP 20 CAN V005
Coding: 00214
Shop #: WSC 31414
65535 - Internal Control Module Memory Error

Address 03: ABS Brakes
Part No: 1C0 907 379
Component: ESP 20 CAN V005
Coding: 18945
Shop #: WSC 01317
65535 - Internal Control Module Memory Error

Address 03: ABS Brakes
Chassis Type: 6Y - Skoda Fabia
Controller: 6Q0 907 379 G
Component: ABS 5.7 FRONT V20
Coding: 00044
Shop #: WSC 13765
65535 - Internal Control Module Memory Error

Address 08:
Chassis Type: 6Y - Skoda Fabia
Controller: 6Y0 820 045
Component: Klimaanlage X0740
65535 - Internal Control Module Memory Error

Address 08:    
Chassis Type: 6Y - Skoda Fabia
Controller: 5J0 820 045
Component: Klimaanlage  X0850
65535 - Internal Control Module Memory Error

Address 08: Auto HVAC
Chassis Type: 6L - Seat Ibiza/Cordoba
Part No: 6L0 820 045 C
Component: Klimaanlage X00.8
65535 - Internal Control Module Memory Error

Address 08: Auto HVAC
Part No: 5J0 820 045
Chassis Type: Skoda Fabia 2
Component: Klimaanlage X0850
65535 - Internal Control Module Memory Error

Address 15: Airbags
Chassis Type: 9N - VW Polo
Part No: 1C0 909 605 K
Component: 18 AIRBAG VW51 0P 0010
Coding: 12600
Shop #: WSC 00788
65535 - Internal Control Module Memory Error

Address 15: Airbags
Chassis Type: 9N - VW Polo
Part No: 6Q0 909 601 F
Component: 05 AIRBAG VW5 0010
Coding: 12341
Shop #: WSC 31414
65535 - Internal Control Module Memory Error

Address 15: Airbags
Chassis Type: 6L - Seat Ibiza/Cordoba
Part No: 6Q0 909 601 F
Component: 01 AIRBAG VW5 0010
Coding: 12337
Shop #: WSC 06441
65535 - Internal Control Module Memory Error

Address 17: Instruments
Chassis Type: 8E - Audi A4 B6/B7
Part No: 8E0 920 900 HX
Component: KOMBI+WEGFAHRS. RB4 D27
Coding: 00142
Shop #: WSC 19411
65535 - Internal Control Module Memory Error

Address 37: Navigation
Part No: 3B0 919 887 D
Component: Navigation  BNO 0201
65535 - Internal Control Module Memory Error

Address 45: Inter. Monitor
Chassis Type: 6N -  VW Polo
Part No: 6N0 951 171
Component: Innenraumueberw. 0002
65535 - Internal Control Module Memory Error

Address 56: Radio
Part No: 1C0 035 157 C
Component: Radio DE2 0004
Coding: 00401
Shop #: WSC 00066
65535 - Internal Control Module Memory Error

Address 56: Radio
Part No: 1J0 035 180 B
Component: Radio DE2 0004
Coding: 01031
65535 - Internal Control Module Memory Error

EXCESSIVE COMMS ERRORS

EXCESSIVE COMMS ERRORS

Looking at the partial scans from several different vehicle platforms listed below, it is quite obvious to see that they all suffer from the same ailment commonly known as--Excessive Comm Errors--from Audi to SEAT, from VW to SKODA. Many VAG car owners have attached their own prefixes to it, like "vag com excessive comm errors", "vcds excessive comm errors", " note excessive comm errors", "vcds lite excessive comm errors", "auto hvac excessive comm errors", "address 08 excessive comm errors", but they all mean the same thing. It says that the scan tool could not communicate with said module because of some obstacle . Perhaps its conflicting with an after market Radio installation on Address 56 or  a combination of VCDS software/protocol/cable. The reason could also be that some other module on the network had been incorrectly configured (module coding) causing the scan tool to struggle to identify said module and after several times attempts fail (timeout) and presents a "Note: Excessive Comm Errors" and perhaps flag a 01044- control module incorrectly coded DTC as well.  However this isn't always the case, because it could also be caused by a setting on the scan tool software--flow control, start and stop bits, etc. The HVAC-address-08, ABS Address-03, Airbag Address-5 etc.. speak protocol KWP-1281 or protocol KWP-2000 and if the incorrect protocol has been selected, the  "Note: Excessive Comm Errors" does pops up. Some HVAC module will also generate a U0324  DTC  meaning that the scanner software is incompatible with the HVAC Control Module or the module concerned. If VCDS doesn't work, try the older VW Tool software or Commander 5,  which I have found has better HVAC and engine fan control settings than VCDS with a VAG-K-CAN cable or KKL-VAGCOM cable. I think the most common reason for excessive comm errors is using the incorrect interface cable because a KII-USB  (K2-USB) cable will not work on cars manufactured after 2005 and a Micro-CAN cable will only work on cars built prior to 1996. So it you have a later vehicle, get the right cable or invest in a Auto Boss V30 or a Launch X31 scan tool because they tend not give  Excessive Comm Errors that the VCDS software/protocol/cable combination is so notorious for. 


Address 01: Engine ---------------------
Chassis Type: 6K - Seat Ibiza / Cordoba
Controller: 6K0 906 032 AC
Component: ME7.5.10 4192
Coding: 00001
Shop #: WSC 06402
Note: Excessive Comm Errors

Address 01: Engine ---------------------
Chassis Type: 6L - Seat Ibiza/Cordoba
Note: Excessive Comm Errors

Address 01: Engine
Chassis Type: 70 (7D - VW Transporter)
Part No: 022 906 032 AF
Component: MOTRONIC ME7.1 G 0003
Coding: 00003
Shop #: WSC 27441
Note: Excessive Comm Errors


Address 02: Auto Trans
Chassis Type: 70 (7D - VW Transporter)
Part No: 01P 927 733 CG
Component: AG4 Getriebe 01P 4893
Coding: 00000
Shop #: WSC 00000
Note: Excessive Comm Errors

Address 03 ---------------------
Controller: 6Q0 907 379 L
Component: FRONT ABS MK60 0101
Coding: 0001097
Shop #: WSC 31414
Note: Excessive Comm Errors

Address 03: ABS Brakes
Chassis Type: 70 (7D - VW Transporter)
Part No: 7D0 614 111 B
Component: ABS/EDS 5.3 D00
Shop #: BB 24258
Note: Excessive Comm Errors

Address 08 ---------------------
Chassis Type: 1M - Seat Leon/Toledo
Controller: 1M0 820 043 D
Note: Excessive Comm Errors
Skipping Address 15-Airbags

Address 08 --------------------
Chassis Type: 4B - Audi A6 C5
Controller: 4B0 820 043 P
Coding: 00063
Shop #: WSC 02325
Note: Excessive Comm Errors

Address 08 --------------------
Chassis Type: 1M - Seat Leon/Toledo
Controller: 1M0 820 043 E
Component: 1M-CLIMATRON
Coding: 00043
Shop #: WSC 06402
Note: Excessive Comm Errors

Address 08: Auto HVAC
Chassis Type: 8D - Audi A4 B5
Controller: 8L0 820 043 D
Component: A4 KLIMAVOLLAUTOMAT_D75
Coding: 04144
Shop #: WSC 06325
Note: Excessive Comm Errors

Address 08 --------------------
Chassis Type: 1M - Seat Leon/Toledo
Controller: 1M0 820 043 D
Component: 1M-CLIMATRONIC X0605
Coding: 00043
Shop #: WSC 06441
Note: Excessive Comm Errors

Address 09: Cent. Elect. -----------
Chassis Type: 9N - VW Polo
Part No: 6Q1 937 049 D
Component: 0000 BN-SG. 1S34
Coding: 00012
Shop #: WSC 06402
Note: Excessive Comm Errors

Address 09: Cent. Elect.  -----------
Part No: 6Q1 937 049 D
Component: 00BP BN-SG. 1S34
Coding: 09358
Shop #: WSC 31414
Note: Excessive Comm Errors

Address 15: Airbags ------------------
Chassis Type: 6Y - Skoda Fabia I
Controller:
Note: Excessive Comm Errors

Address 15: Airbags
Chassis Type: 70 (7D - VW Transporter)
Part No: 1J0 909 603 BM
Component: AIRBAG VW3 - V04
Coding: 16973
Shop #: WSC 02743

Note: Excessive Comm Errors

Address 17: Instruments  -------------
Part No: 6L0 920 801 A
Component: KOMBI+WEGFAHRSP VDO V13
Coding: 00145
Shop #: WSC 00000
Note: Excessive Comm Errors

Address 17: Instruments ---------------
Chassis Type: 6L - Seat Ibiza/Cordoba
Part No: 6L0 920 801 A
Component: KOMBI+WEGFAHRSP VDO V13
Coding: 00145
Shop #: WSC 00000
Note: Excessive Comm Errors

Address 17: Instruments
Chassis Type: 70 (7D - VW Transporter)
Part No: 7D0 920 902 T
Component: T4-KOMBIINSTR. VDO V01
Coding: 03235
Shop #: WSC 02743
Note: Excessive Comm Errors

Address 19: CAN Gateway ---------------
Chassis Type: 6L - Seat Ibiza/Cordoba
Note: Excessive Comm Errors

Address 19: CAN Gateway
Chassis Type: 70 (7D - VW Transporter)
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00001
Shop #: WSC 02743
Note: Excessive Comm Errors

Address 25: Immobilizer  --------------
Chassis Type: 9N - VW Polo
Note: Excessive Comm Errors

Address 25: Immobilizer
Chassis Type: 70 (7D - VW Transporter)
Part No: 6X0 953 257
Component: IMMO 0008
Coding: 00001
Shop #: WSC 20309
Note: Excessive Comm Errors

Address 35: Centr. Locks
Chassis Type: 70 (7D - VW Transporter)
Part No: 7D0 959 800 C
Component: Funksteuergerát 0001
Coding: 00001
Shop #: WSC 02743
Note: Excessive Comm Errors

Address 44: Steering Assist ------------
Chassis Type: 6Y - Skoda Fabia I
VCID: 55AA04A28569
Note: Excessive Comm Errors

Address 56: Radio ---------------------
Chassis Type: 17 - VW Golf Citi
Controller: 17S 035 186
Note: Excessive Comm Errors

Address 7E: Ctrl Head Dash -------------
Chassis Type Audi TT
Protocol: KWP2000
Controller:
Note: Excessive Comm Errors

KNOCK SENSOR

VAG KNOCK SENSOR K1 AND THE EPC LIGHT

VW, Seat, Skoda  and Audi Knock sensors have become quite notorious for sending the car into "limp mode". Limp mode is a safety feature on all Drive by Wire vehicles, implying an EPC-electronic power control-but no accelerator cable. EPC implies torque control. By analogy,  its something like a horse that gets spooked and takes off at high speed and out of control with its rider unable to rein him in,  or a frayed accelerator cable that becomes stuck while driving at high speed. That's just a recipe for disaster. Imagine stepping on the brake pedal but the high revs of the engine just forces the car forward, smoke pouring from the brake pads to the point that the become glazed and  no longer has any effect. Pushing the transmission into neutral isn't an option because without the load, the engine is destined to blow, perhaps even push a piston  through the side of the engine lock.  Drive by wire prevents this from happening and cuts power to the powertrain if it detects a fault that puts the engine at risk. Knock reacts somewhat similar to backfire since both are due to detonation and pre-ignition-incomplete combustion.

Detonation is a common problem associated with lean fuel mixture -non stichometric-and torque. The EPC light is often triggered on an incline when the torque is insufficient to pull the car uphill when in an inappropriate gear. Knock sensors can detect combustion knocks in individual cylinders. Knock sensor 1 (G61) senses cylinders 1 & 2, and knock sensor 2 (G66) senses cylinders  3 & 4. To prevent combustion knock, the ECU cylinder selective knock control overrides the electronic control of the ignition timing by retarding the timing, but may not be unable to if the Fuel Octane is too low causing secondary combustion in the cylinder. Knock sensor 1 (G61) is known to trigger EPC light and activate limp mode, hence it needs to be checked for flush engine contact and correct torque. DTC  P0171 and P0174 could show up in scans.

The ECU calculates engine ignition timing based on input signals from Throttle Position (TP) Sensor G79 and  Accelerator Pedal Position G185, the  Engine Speed (RPM) Sensor G28,  the load signal from Mass Air Flow (MAF) Sensor G70, the signal from the Throttle Valve Control Module J338,  the Coolant Temperature (ECT) Sensor G62, both Knock Sensors G61, G66 (additional G198 & G199 on V6, W8 & W12 engines) and signals from Camshaft Position Sensors G40, G163, (additionally G300, G301 on V6, W8 & W12 engines) When the engine is below 40 degrees  celsius knock sensors signals are not used to make timing decisions. What this implies is that when the EPC light turns on  when the engine is still cold, the knock sensors are not guilty , neither  the the Mass Air Flow (MAF) Sensor G70 nor the Coolant Temperature (ECT) Sensor G62 since whilst idling, have nothing to do with torque. That leaves the Accelerator Pedal with G79 & G185, the Throttle  Control body senders G187 & G188,  the  Engine Speed Sensor G28,  Camshaft Position Sensors G40 & G163 as the EPC limp mode culprits. However sensors are fairly reliable but the wiring  harnesses  are  more likely to be the cause of the problem, see wiring in Audi.

Fuel pressure regulator valve N276, the wastegate bypass regulator valve N75 and the  Ignition Coil N, N128, N158, N163 and its Power Output Stage N122 are three  more EPC culprits. Injectors N30-N33 can also cause the EPC light to turn on and cause car to go into "limp mode" but also causes the engine not to run smoothly. Once again before condemning the sensors or actuators, check the wiring harnesses to them.



EPC light
Epc light?
EPC light on
EPC light problem
EPC warning light?
EPC and ESP Problems
EPC and ABS warning lights on
EPC warning light, advice welcome
EPC Light and stalling
EPC what does this mean?
Epc Light that keeps coming on
EPC light and starting issues
EPC light come on frequently
EPC light pain in my butt
Epc Light On Power Loss
EPC warning light - car shakes violently - ideas?
EPC light & locked in Park. 2006 A6, need solution.
EPC light / Check Engine light - Audi not finding issue
EPC light came on and can't start the engine
EPC light coming on and difficulty starting
EPC warning light and stalling in traffic
EPC warning light is on the dash and another lamp
EPC light came on and there was lots of shudder
EPC light has just come on and doesn't go away
The EPC light came on and I had sluggish power
The EPC warning symbol came on today while driving.
The EPC warning light has been triggering fairly regularly
The warning light EPC does not go out or comes on or flashes
Occasionally the EPC light comes on
EPC Light comes on at 4000 rpm - clears on restart
EPC warning light?? 15 Nov 2011
EPC Light comes on at 4000 rpm - clears on restart 3 Mar 2011
My EPC and CEL (Check Engine Lamp) is on
My EPC light is now light on the dash
My EPC light goes on/off on a daily basis
My check engine light and EPC light is on
My Audi's epc light came on this morning
My epc light and check engine light came on
My EPC light came on then I tried to start the car but nothing happened
What is the EPC warning light?
what's the mean of epc light, when it's come on ?
When I start the car the EPC light on the dashboard stay on
when epc light's come on, car loosing power
What is epc warning light mean on a seat ibiza
Check Engine Light & EPC Light came on
When you try and accelerate the EPC light comes on and the throttle cuts out
Why does the epc light keep coming on in my audi a4
A4 with EPC light, stalling at dangerous times
Audi Q7 EPC engine management warning light
I have EPC warning light and acceleration problems
I'm having a problem with the EPC light on my 2003 Audi A4 2.0FSI
I keep getting the epc light come on
j'ai le voyant EPC qui reste allumé
Having EPC problems with a skoda fabia 1.4
Seat Leon 52 plate EPC light
Seat ibiza 1.2 EPC and Engine light on
Seat Ibiza EPC light on and acceleration problem?
Fabia EPC Light on
Seat arosa EPC light?
How do I reset a Seat Arosa EPC light?

The above EPC errors are common to Volkswagen, Audi, Skoda and Seat. The  VW, the 4motion, the Amarok, the new Beetle, the Bora, the Caddy, the Corrado, the CC, the Eos, the Fox, the Golf, the Jetta, the Kombi, the Lavida, the Lupo, the Passat, the Polo, the Phaeton, the Routan, the Santana the Scirocco, the Sharan, the Tiguan, the Touran, the Touareg, the Transporter, the Vento , the Up and lastly the Vivo. The Audi A1, A2, A3, A4, A5, A6, A7, A8, the Q3, Q5, Q7, the RS4, RS6, RS8, the R8, the S4, S6, S8, Audi TT. The  Seat Alhambra, the Altea, the Arosa, the Cordoba, the Ibiza, the Inca, the Leon, the Mii and the Toledo,  Skoda  Felicia, the Octavia, the Fabia, the Superb, the Roomster, the Yeti, the Rapid and the Citigo. The Audi RS-6, A4 Fsi, Audi A4, Audi S3, Audi TT, Audi R8, audi a4 2.8 quattro 5 speed, Skoda fabia, seat leon, seat ibiza, Avant RS 2, Coupé, Audi A3 Mk1, Volkswagen Golf Mk4, Volkswagen New Beetle, Volkswagen Bora/Jetta Mk4, SEAT León Mk1, SEAT Toledo Mk2, Škoda Octavia Mk1,  TFSI, FSI, GTI, TDI,