# EPC light and car ignition problem



## Janne (Feb 21, 2012)

Hello all,

I tried to search the net, this forum and FAQ but I am still puzzled with a problem that I am having. Can anyone show me the direction where to find the answer (if it's already covered)?

This winter I have had four different occasions in which the EPC light came on then I tried to start the car but nothing happened. Car will not absolutely try to do anything, not even revving the start motor. Battery isn't a problem, it has been checked. Problem came randomly and interval between the incidents varied from 3-5 weeks. 2 first time I manged to start the car after retrying but two latter times I didn't succeed. The only solution that worked is that I unplugged the battery and did a hard reset. Then the car would start normally and usually I could run another 3-5 weeks without any problems.

EPC stands for Electronic Power Control, is that correct? And it's lit when a test fails in bigger set of tests ran by ECU, is that correct?

Now, does anyone know what are the tests that are included in this run? There's a lot of assumptions and guesses what might cause this, ie. crank speed sensor but is there any good practise to narrow down the problem?

I noticed after last hard reset that engine temperature gauge didn't show correct figures (90 degrees C). My dashpod has been fixed by replacing the integrated circuit and it has been working before. This problem might be caused by faulty thermostat or sensor but can that be the cause of the EPC issue as well?

Any help is appreciated, thanks in advance!

Cheers, J


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## Janne (Feb 21, 2012)

*bump*

Does anyone got any suggestions?

Yesterday the car left me at my office. I couldn't do anything to start it (EPC light was on) and I was forced to have it towed away.

I will be posting more info later next week when the car is taken under job.

Cheers, J


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## antcole (Apr 4, 2009)

Hello mate,
Have you scanned the car for faults?
Might be beneficial to buy an OBD2-USB cable and get VAGCOM/VCDS software to scan the car yourself, im sure if it is a recurring problem, there will be a fault code stored in the ECU etc and that will help to pinpoint your problem.
I have heard of people having troubles with crank sensors causing exactly your problem.

I was in Helsinki during January a few years ago, stayed just outside at a place called Espoo and i know how cold it gets there!! The roads were solid ice!!
Is it possible theres a problem with the cold affecting the ECU or throttle body....?
There may just be a wiring fault between the accelerator pedal and ECU or the throttle body and ECU.
A VAGCOM/VCDS scan should help you, or you might need to go to a VWAudi dealership and get it scanned there.

Sorry i cant help more but ill keep thinking anyway.


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## Janne (Feb 21, 2012)

Hi mate,

Thanks for your answer.



antcole said:


> Have you scanned the car for faults?
> Might be beneficial to buy an OBD2-USB cable and get VAGCOM/VCDS software to scan the car yourself, im sure if it is a recurring problem, there will be a fault code stored in the ECU etc and that will help to pinpoint your problem.
> I have heard of people having troubles with crank sensors causing exactly your problem.


I haven't scanned the car. I don't own the cable nor the software. Maybe that's an investment I should make. I currently don't have a laptop though, so, dragging a desktop around isn't an option here  I live in the city and don't have a regular parking slot for the car so, depends on the day it's always in different place.

I am sure though the codes will be read when the car gets under job.



antcole said:


> I was in Helsinki during January a few years ago, stayed just outside at a place called Espoo and i know how cold it gets there!! The roads were solid ice!!
> Is it possible theres a problem with the cold affecting the ECU or throttle body....?


Yeah, Espoo is next to Helsinki. It can get quite cold sometimes but usually problems come with batteries and if water has accidentally gotten into wrong place and it freezes, it can cause trouble. Other than that, my car has been running fine for 5 winters so basically cold is not an issue if car parts are in good condition.



antcole said:


> There may just be a wiring fault between the accelerator pedal and ECU or the throttle body and ECU.
> A VAGCOM/VCDS scan should help you, or you might need to go to a VWAudi dealership and get it scanned there.


Yeah, I am sure I know more when the codes are read. I try to post more information of this later.



antcole said:


> Sorry i cant help more but ill keep thinking anyway.


No worries  And thanks for the insights.

Cheers, J


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## antcole (Apr 4, 2009)

Theres a possibility its simply down to a problem in the ignition key barrel and contacts, especially as you say that the engine doesnt even turn over....

If there was an issue with ECU, crank sensor, throttle body or accelerator pedal.... you would still be able to turn the engine over but without actually starting.

The more i think about it, the more it sounds feasible, i dont know of any starter inhibit logic with the manual gearbox....

Yours is manual i assume??

The auto gearbox has a starter inhibit safety feature (all autos do) and its generally a contact inside the selector housing in the cockpit.
This will block the engine turning over for sure....


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## NoMark (Jul 6, 2011)

What about the immobiliser, does that prevent engine cranking when it's activated?

Mark.


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## nate42 (Apr 9, 2008)

Hi Janne,

Where in Helsinki you live? I live in downtown and I got the cable and VAG-COM so I can read your error codes some evening.


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## Janne (Feb 21, 2012)

Hi guys,

My good luck with cars continues... Today a big SUV hit on the right side of my friends car . Luckily this happened on a parking area and there was not much speed. The SUV was reversing and obviously was required to give way thus he took the blame totally. Nevertheless... When things start to develop like this, one starts to wonder what happens next 



antcole said:


> Theres a possibility its simply down to a problem in the ignition key barrel and contacts, especially as you say that the engine doesnt even turn over....
> 
> If there was an issue with ECU, crank sensor, throttle body or accelerator pedal.... you would still be able to turn the engine over but without actually starting.
> 
> ...


My car is manual yes. I am not quite sure how ignition barrel or ignition "base" contact issues or problems would come up but I would imagine that you could work around this issue by trying multiple times and if it's not 100% broken car should start at least once?

You see, once or twice I managed to start the car just by doing a hard reset, nothing more. I unplugged the battery, turned the key to have power into car and then turned it off, plugged the battery and voilá car starts immediately. For me it sounds that if the problem would be with ignition barrel / base then this wouldn't happen?

I am not quite sure what you mean "turn engine over". With my EPC light lit on the dash I can turn the car on, to have the power but turning the last bit (thus starting the engine) it doesn't even allow the "start" motor to rotate. I am not sure if this is appropriate term or not.



NoMark said:


> What about the immobiliser, does that prevent engine cranking when it's activated?


You are guessing it would have something to do with the immobiliser? I don't know what should it say on the dash if you would try with a different key or with a key that has not been linked with your car. I have a set of new keys (1,5 yrs old), but of course, there's some electronics in the car's side as well. Error codes will probably say something about this.



nate42 said:


> Where in Helsinki you live? I live in downtown and I got the cable and VAG-COM so I can read your error codes some evening.


Oh, that's very kind of you. I live also downtown. But now the car has been towed to a garage and they will read the codes for sure (when they start actually working with the car). I don't want to be pain in the ass anyway, but maybe if something like this should happen in the future, maybe I can bother you a bit, in case I don't get help anywhere else?

Anyway, I appreciate your feedback and opinions. I try to keep you update when I know a bit more.

Cheers, J


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## nate42 (Apr 9, 2008)

Could be something with the immobilizer as suggested because the starter motor doesn't even turn the engine. I hope you get it sorted at a reasonable price, reasonable price and Audi Finland are not too often mentioned together.

If you need some expensive spare parts ask a list of the parts and part numbers and look if you get them cheaper here:
http://speed-autoteile.fi/
This guy imports the parts himself from Germany (authentic Audi parts), they can be half the price!

I can help with reading the codes at a price of one beer at the local pub :wink: I've done quite a bit of work to my TT so I know the most common problems. This forum has tons of info, easiest way to search it is with Google, for example:
'site:********.co.uk EPC light' to look for EPC light related posts.


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## Janne (Feb 21, 2012)

Hi mate,

Thanks for the reply. I will check that site for the parts. It's good to know there's alternatives.



nate42 said:


> I can help with reading the codes at a price of one beer at the local pub :wink: I've done quite a bit of work to my TT so I know the most common problems. This forum has tons of info, easiest way to search it is with Google, for example:
> 'site:********.co.uk EPC light' to look for EPC light related posts.


I wouldn't have it any other way 

Cheers, J


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## Janne (Feb 21, 2012)

Hi all,

Fast info about the car: The codes have been read but there wasn't any. Strange. The mechanic said he even resetted the whole system and cleared the codes. Then he tried to start the car but no codes were stored.

Nevertheless, next step, he said, is to test the ignition barrel and if that's ok, the start motor (since it doesn't rotate).
I also suggested the immobilizer but he said it shouldn't be immobilizer since the icon (car with the ky) in dash disappears (which should indicate that the key is recognized) and that if it should be immobilizer car would actually start but then immobilizer would immediately turn it off.

I will be posting more info about this when I know more...

Cheers, J


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## antcole (Apr 4, 2009)

Janne said:


> Hi all,
> 
> Fast info about the car: The codes have been read but there wasn't any. Strange. The mechanic said he even resetted the whole system and cleared the codes. Then he tried to start the car but no codes were stored.
> 
> ...


My bet is on the ignition barrel contacts or the relay.....


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## Janne (Feb 21, 2012)

Hi all,

Update: The start engine has "blown" up. The ignition barrel is actually giving the correct voltage but it's in the end of it's lifespan and mechanic said it should be replaced now.

So the start motor has to be replaced. It was damaged due to the short circuit (reason is unknown).

EPC light probably had nothing to do with the actual problem in this case.

If car works after start engine + ignition barrel replacement then all good. I will be posting more info after the replacement has been made.

Cheers, J


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## Janne (Feb 21, 2012)

Hi all,

update: Car is back on the road and running just fine. Problem was the start engine. Now after replacing the start engine and ignition barrel car is starting and running just fine.

So EPC light didn't have any role in this play. There wasn't any error codes either. Not much I could have done myself 

Nevertheless, hopefully this information will help someone else at some point.

Cheers, J


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## jamman (May 6, 2002)

Glad you got there in the end


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## dmc (Jul 6, 2011)

What was the cost of fixing it?


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## Janne (Feb 21, 2012)

Hi mate,

New ignition barrel: 60€
New start engine: 220€

Job: 3-5 hours (not by me)

Cheers, J


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