CEL and no code?

[DJYoshaBYD]

ok.. I have been having this problem... When I start my car, no CEL, then after a couple of minutes (if that) it comes on until I turn the car off, then the same thing.... the time it comes on varies, though... Sometimes it will take a 30 seconds and sometimes 5 minutes...

I tried to read a code and there was NO CODE!!! I cant figure it out.. The only thing I can think of is misfire because the only thing that wasnt from my tsi was the coil packs for the ignition... Those are the stock NA coils..

Anyone had this happen?

 

[gdmbat85]

You may be correct about the misfire theory. I believe i read somewhere that the ECU doesn't store the code for a misfire, only because it's pretty much a random event. It just winds up resetting it when you turn off the car. Try checking for codes while the car is still on.

 

[tqmx1]

I don't know the history of your ECU but our tallon did it a couple of times just before the caps took a dump. Also when the CEL came on the engine went to auto rough until the light went back out and never a code.

It's a cheep fix if you catch it early

 

[DJYoshaBYD]

the car doesnt run bad when it happens, the light just turns on... I will try to check with it running... It didnt do it before, and as soon as I changed motors, it did it... The only thing I didnt change is the coil packs

 

[spyderturbo007]

Pull the ECU and check the caps.

 

[DJYoshaBYD]

How do I check them and what are they?

 

[JohnCIV_Talon]

I have the same problem right now. I was wondering if the check engine light would come out if your battery was to weak, becasue i recently installed a new stereo and havent had one in before. Also the guy who put it in said my battery was pretty weak.

 

[JohnCIV_Talon]

I mis read, my comes on as soon as teh car starts and stays on.

 

[steve]

Get a datalogger or make a code reader. You need to read the code while it's happeneing to see if you have a real error or some other problem.

A big LED with the current limiting resistor works great as a code reader for things like this.
Pin 1 on the diagnostic connector is positive and pin 12 is ground.

Steve

 

[JohnCIV_Talon]

I have a data logger but no code would show up, even this mechanic with a 8k logger kinda thing duidnt have a code.

 

[steve]

I have a data logger but no code would show up, even this mechanic with a 8k logger kinda thing duidnt have a code.

This is called a thread hyjack. Your problem doesn't have anything to do with the Original Posters problem since he has a 1G and you have a 2G. Please open your own thread.

Steve

 

[Doug99RS]

DJYoshaBYD

It's possible that the computer is on the fritz like everyone else is saying. Regardless of the year model the circuit board in the ECU could have components that are leaking and causing circuits to short together causing the CEL light to come on intermittantly while still not storing a code. In addition to that, if the code IS there while the key is on only but goes away once the key is shut off then one of two things is happening. The computer is not retaining the memory (usually because of a bad ECU) or the condition is not present the next time you start the car and thus the CEL does not come back on.

The proper diagnostic approach to this is to attempt to retrieve the fault codes (as everyone else has suggested) while the light is still on and the engine is still running.

I don't feel this is going to be a "Mis-fire" code because from my experience, the Mis-fire monitor and related fault codes (P0300 multiple cylinder, P030X with X being the affect cylinder) were not a programed feature until the introduction of OBDII which as not present on the 1g's.
Doug