Audi a2 bby 1.4 petrol accelerator pedal

zago

zago

Member
Hi everyone,

I had to pull aside yesterday as accelerator started to work very strange. Pushing the pedal and nothing happens. Turned off/ on an engine accelerator works for few seconds and afterwards engine dies. Put a car on parking. When starting engine it accelerating automatically without pushing a pedal. Is this potentiometer on pedal?
 
zago said:
Hi everyone,

I had to pull aside yesterday as accelerator started to work very strange. Pushing the pedal and nothing happens. Turned off/ on an engine accelerator works for few seconds and afterwards engine dies. Put a car on parking. When starting engine it accelerating automatically without pushing a pedal. Is this potentiometer on pedal?
Click to expand...
Additionally just to add. Every morning my accelerator doesnt work normally after start. Maybe it is not related.
 
Generally never really heard of issues, however heck this thread out.

Accelerator pedal sensor

As the title. Having the ongoing problem with this sensor according to VCDS I managed to take off the pedal Im going to attempt to open this up and try and clean it up, has anyone ever opened one up and if so are there any springs and such that will launch themselves and never found again...
www.a2oc.net www.a2oc.net
 
CrispyEdd said:
Generally never really heard of issues, however heck this thread out.

Accelerator pedal sensor

As the title. Having the ongoing problem with this sensor according to VCDS I managed to take off the pedal Im going to attempt to open this up and try and clean it up, has anyone ever opened one up and if so are there any springs and such that will launch themselves and never found again...
www.a2oc.net www.a2oc.net
Click to expand...
Checked this already. Thanks
 
CrispyEdd said:
Generally never really heard of issues, however heck this thread out.

Accelerator pedal sensor

As the title. Having the ongoing problem with this sensor according to VCDS I managed to take off the pedal Im going to attempt to open this up and try and clean it up, has anyone ever opened one up and if so are there any springs and such that will launch themselves and never found again...
www.a2oc.net www.a2oc.net
Click to expand...
Checked this already.
mtl said:
Did diagnostic showed any faults?
Click to expand...
I’ll try to check today.
 
zago said:
Checked this already.

I’ll try to check today.
Click to expand...
I would expect something to show up on the scan, according to SSP 247 the accelerator sends signals to the ECU (G79/G185) and also sends and receives signals from the throttle body (G186/V60). You might try remaking the connections at all these components (remove and refit) in case there is any oxide build up on the connector pins.
 
Looks like more troubles than expected. Probably no communication with abs and steering is the main cause. System too lean is old problem on this car. When i bought it there was no communication with diagnostic tool at all. Looks like electrician did only part of his job.
 

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Today accelerator is working again normally so problem is on the wiring ….somewhere
 
Cleared faults and drive to home. No communication between j500 and ecm appeared.
 

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Is your battery in good condition, and fully charged? If not, that could be the problem.
Look for around 13.5 V across the battery, ignition off, lights off, then around 12 V with ignition on, first position (engine not running), and dip lights on. Much less, and the battery is suspect.
Mac.
 
Merry Christmas guys. I had a ton of misleading fault codes with the Marelli ECM. First of all check battery voltage and if you have a battery conditioner, fully charge the battery. If that is ok, next culprit for the intermittent accelerator pedal malfunction is the throttle body. Check Engine-> Group 60 if the Adaptation has an Ok status. If so perform a Basic Setting, it is known that B spec throttle bodies are notorious for this. If spec N and Ok status should be ok but re adapt that to cross it off from the list. Next step Engine-> Group 74 EGR Adaptation status. Re adapt that as well, could be sticking a bit and that forces the Marelli to see extra air and throws whatever code it feels like to.

Disregard the intermittent codes between the different modules at this stage. Something is drawing more voltage/currrent that it is suppossed so and the Marelli is either crashing and rebooting or sees the flactuation and throws the code. Get back to us after you give those a shot.
 
Looks ok. As there no more the same faults probably needs to drive but so annoying doing this knowing it can stop on busy road in the morning.
 

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Yeah, i know the feeling. I've been left without an accelerator pedal in the middle of an intesection due to a stuck EGR. Drive it around a bit, if it is from the Throttle Valve or EGR it will come up in a start stop city kind of traffic. If not some build up to either of the valves, will be countered out with the adaptation as it measures the difference. If you notice any small jerks when in part throttle, or under light acceleration, either the valves or the EGR pipe going back to the throttle body base needs to be cleaned due restrained flow. Keeping my fingers crossed that it was just a re adaptation thing.
 
The same again. Engine died while drive with lights on dash. After couple of minutes worked again. All faults are the same except one:
After those tests that you suggested to do (60,74) one fault changed before was “ fuel too lean” and now is “efficiency below threshold”
 

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Crap dude, it took enough time so if you use the car every time about the same period & mileage, it should have occured earlier. As before ignore the intermittent communication errors. Voltage flactuation from the cut off or sth similar. So let's start a guessing game. I presume that you hear no rattling or metal clicking coming from the catalytic converter/underside.
So let's make the car run rich for a while, in order to either force an oxygen sensor to pop an error and lead us that way or just to rule out that an oxygen sensor might be acting up and Marelli being "nice guy" does not want to tell on him.
Simply unplug the EGR plug while the car is turned off and key out of the ignition. Engine light will stay on. If you notice a hunting idle after that we got the culprits, if not just drive it around and scan the ECM every now and then for anything new. Fuel Consumption will go up by max 1 l/100km.
Don't lose your nerve, we will work it out!!! :)

P.S. recheck voltage/condition of battery
 
zago said:
The same again. Engine died while drive with lights on dash. After couple of minutes worked again. All faults are the same except one:
After those tests that you suggested to do (60,74) one fault changed before was “ fuel too lean” and now is “efficiency below threshold”
Click to expand...
To me it seems that you have an engine ecu problem. Both the instrument and the brake ecu are reporting that they no longer hear the communication from the engine ecu.
And as you also experience that the engine dies it seems that the engine ecu shuts down.
I would start thinking on:
1. its power supply, including its ground.
2. faulty ecu (internal fault) , try with another one
 
Joga said:
To me it seems that you have an engine ecu problem. Both the instrument and the brake ecu are reporting that they no longer hear the communication from the engine ecu.
And as you also experience that the engine dies it seems that the engine ecu shuts down.
I would start thinking on:
1. its power supply, including its ground.
2. faulty ecu (internal fault) , try with another one
Click to expand...
This car had a communication problem since I bought it. Vcds didnt work so the electrician helped with this and diagnostic tool start working. CAN problem. It was repaired last summer. Now in winter this happened. My guess is again on wiring can.
Electrician “didnt remember” where the problem was. Asked him already. I guess he thought i will bring him the car again.
 
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Does anyone had problems with CAN wiring?
Is any common places of wiring failures?

Earth point (left side driver side on LHD) checked already it was ok.
 
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