Multiple Pcm Fault Codes And Engine Cuts Out At Constant Speed

[Swede-4WD]

Hi

 

I have for a longer period had a growing problem with sporadic fault codes (from my VAG-COM) from the PCM indicating all sorts of sensor faults.

(Beside that I have a constant fault "00533 - Idle Speed Regulation" that existed before these problems started. I have not yet come around to fix it since I have no problem with the idle speed or the emmisions at ideling.)

 

With increasing number of fault codes the engine also starts to cut out when I have constant speed and revs around 1500-3000 rpm. As soon as I accelerate a bit the power comes back.

 

When I reset all the fault codes the engine runs fine for a while until some codes come back (some new and some of the same as before).

 

My only conclusion so far is that I probably have a grounding or power supply problem for the PCM, but before tearing half the interior and the dashboard apart to be able to get to the PCM I thought I'd ask you out there if you have had any similar problems.

 

 

The car is a Ford Galaxy 1999 with VR6-2.8i, Automatic Transmission and 4x4 that now have just past 150.000 km.

 

VAG-COM headig on all fault codes are:

VAG-COM Version: Release 303.1

 

Control Module Part Number: 021 906 256 AE

Component and/or Version: MOTRONIC M3.8.1 AT V01

Software Coding: 00001

Work Shop Code: WSC 00020

 

The fault history and codes look like this in cronological order with oldes on top:

16 Mar-09

2 Faults Found:

00533 - Idle Speed Regulation

14-00 - Adaptation Limit (Add) Exceeded

00525

[big_kev]

Try looking here

 

http://wiki.ross-tech.com/index.php/00533

 

You can input the other codes into the search on the left.

Most of them will be there.

Edited August 5, 2009 by big_kev

[Mirez]

A failing MAF will cause all kind of mixture issues and the fact that it keeps popping in there might not just be by chance, the oxygen/HEGO sensor is in the exhaust system and because of the harsh life they have they do fail over time. Those two sensors being defective could easily be the cause of your mixture error and the poor running. I'd be looking at a replacement MAF to start - the codes arn't that random to make me think its a grounding issue, more a couple of sensors on the way out.

[Swede-4WD]

A failing MAF will cause all kind of mixture issues and the fact that it keeps popping in there might not just be by chance, the oxygen/HEGO sensor is in the exhaust system and because of the harsh life they have they do fail over time. Those two sensors being defective could easily be the cause of your mixture error and the poor running. I'd be looking at a replacement MAF to start - the codes arn't that random to make me think its a grounding issue, more a couple of sensors on the way out.

Thank's Mirez

 

I have exchanged the MAF and the Gal haven't had any unclean runs since that (4 days now).

I also got a new HEGO since I saw it was recommeded to change it after 160.000 km and I am running up to it very soon.

 

Any one knows if there are anything to do about the:

00533 - Idle Speed Regulation

14-00 - Adaptation Limit (Add) Exceeded

Is there anything to trim here or is there some standard part that has to be exchanged.

As I recall it I had the same sort of fault some years ago when she had been going aroun 80.000 km.

To my weak memory the repair shop changed some stepping motor.

 

Best Regs Tomas

[sepulchrave]

Hello,

 

Yes, the 'adaption limit exceeded' simply means that the ECU feels it is having to add too much throttle using the stepper motor to maintain a decent idle.

 

If you change the MAF and the HEGO sensor please remember to disconnect your battery and short the terminals to clear the adaptive fuel map and force the ECU to relearn from base settings. This should sort out all the other problems, but will take a few hours driving to do so.

[Swede-4WD]

Hello,

 

Yes, the 'adaption limit exceeded' simply means that the ECU feels it is having to add too much throttle using the stepper motor to maintain a decent idle.

 

If you change the MAF and the HEGO sensor please remember to disconnect your battery and short the terminals to clear the adaptive fuel map and force the ECU to relearn from base settings. This should sort out all the other problems, but will take a few hours driving to do so.

Hi,

 

I have changed both MAF and HEGO, but not shortened any terminals.

 

The terminals you talk about is that +12v to ground on the battery leads?

If so, how long will they have to be shorted to be sure the ECU will start relearning?

What other things will start to relearn after this action?

 

Is there no way to tell the ECU e.g. from VAG-COM that the ECU shall relearn?

 

BR Tomas

[sepulchrave]

Yes, short the +ve to ground for about 30 seconds with the battery disconnected.

 

The dynamic ignition map will also be reset.

 

No, you cannot wipe the maps with VAG-COM, only the fault memory.

 

Ok?

[Swede-4WD]

Thanks sepulchrave

 

It worked with shorting +12v to Gnd and after restarting the car it stopped a few times before it started running clean.

 

When entering VAG-COM I had to clear the codes for the power loss and the Idle Speed Regulation and since then there hasn't been any faults at all (30 minutes testrun with a lot of stops). Hope it stays that way. Will check again in a week or so.

 

Anyone for an idea why the VAG-COM indicate the Readiness Status as:

Exhaust Gas Recirculation: Passed

Oxygen Sensor Heating: Failed or Incomplete

Oxygen Sensor(s): Failed or Incomplete

Air Condition: Passed

Seconday Ait Injection: Passed

Evaporative Emissions: Failed or Incomplete

Catalyst Heating: Passed

Catalytic Converter(s): Failed or Incomplete

 

It has been this way for about 3 year, but all external meassurements of emmisions has passed both the workshops yearly service (and I specifically ask them to meassure this and I got back the data and an OK) and the yearly regulatory car inspection.

 

I have an old printout that show that about 3 years ago the only failed Readiness was the Evaporative Emissions.

 

Best Regs Tomas