ABS/PSM light on 996 Turbo

[jipettersen]

I have a 2001 996 turbo with 35 000 km.

Ruf ex. and Sportec ECU (Tiptronic)

After installation of Ruf exhaust and Sportec engine management i went 5000 km with no trouble. The car is running like h.... Max boost 1.1 bar.

Then the CEL lamp started to light. MAF sensor was changed and everything was OK again.

Then i discover under hard acceration (approx 1 bar 4- 5000 rpm in 3.,4.gear) that the ABS/PSM lamp went on.

This was reset when i started the car again.

First my dealer was assume air leaks in the pipes. No leakes were found but bad diverter valve. They were changed with newer type.

ECU has also been reset and loaded with Sportec SW again.

But still the ABS/PSM is lighten up.

The faul codes is P0103 MAF sensor ( has been changed 3 times so this is not a real error)

and 5525 Torque tranfer from DME disturbed at times.

When it throw the 5525 code is seems to be a defect ECU box, or ???

Spoked to Techart. They told me i must have an air leak. Maybe in air hose into / from the intercoolers.

The engine is running fine alle the time. Just my lack of ABS/PSM.

This is really frustrating. Starting to take my sleep away.

Any suggestions what to do next???

Any support will help a lot.. :clapping:

[Loren]

Are you sure the MAF id connected -- you get the same symptom if you unplug the MAF.

[jipettersen]

Are you sure the MAF id connected -- you get the same symptom if you unplug the MAF.

First, thank for the answer.

Well i don't know.

First the official Porsche dealer ( were i bought the car. It's still under Porsche warranty) changed the MAF. Then another Porche dealer tried a new MAF again. Same 5525 and P0103 codes. I suppose they now the test procedure, or not ?

But will the car work at all with the MAF disconneted? As i said, my car is working like normal until i accelerate hard. Then the codes above appear.

Is it just to disconnect the MAF and take a test drive to see if the same happens?

[Loren]

I wouldn't worry about 5525 - every TT w/Tip I have looked at had that same code.

The car will run at low RPMs fine with the MAF disconnected. What you will lose is high RPM - but the turbo may mask that somewhat.

It sure sounds like you have no MAF signal and any dealer should be able to test that easily with a PST2 or PIWIS tester.

If it is not the MAF then they should be looking at the connector and wiring or the throttle jacking.

The diagnostic manuals lists:

P0103 - Possible fault cause

-Intake air system on pressure side (between turbocharger and engine) leaks

- Short circuit to B+ (B+ is + 12 volts)

- Mass air flow sensor faulty

- Throttle jacking unit faulty

The reading on a Porsche System Tester should tell them if the MAF is changing with engine speed (intake air flow).

[jipettersen]

I wouldn't worry about 5525 - every TT w/Tip I have looked at had that same code.

The car will run at low RPMs fine with the MAF disconnected. What you will lose is high RPM - but the turbo may mask that somewhat.

It sure sounds like you have no MAF signal and any dealer should be able to test that easily with a PST2 or PIWIS tester.

If it is not the MAF then they should be looking at the connector and wiring or the throttle jacking.

The diagnostic manuals lists:

P0103 - Possible fault cause

-Intake air system on pressure side (between turbocharger and engine) leaks

- Short circuit to B+ (B+ is + 12 volts)

- Mass air flow sensor faulty

- Throttle jacking unit faulty

The reading on a Porsche System Tester should tell them if the MAF is changing with engine speed (intake air flow).

Thanks for the answer.

They claim they have checked the intake system for leaks. No leaks found but DV were gone. DV was changed.

MAF sensor changed 3 times

Throttle jacking unit not checked, just calibrated. Maybe it need cleaning?

Short circuit. Do you mean on the MAF connector wire?

Anyway, just to eliminate. We will also change the gaskets to/from the intercoolers.

Do you mean that the 5525 code is nothing to worry about and that this is not the couse for ABS/PSM lamp and that this is related to the P0103 MAF?

[jipettersen]

I wouldn't worry about 5525 - every TT w/Tip I have looked at had that same code.

The car will run at low RPMs fine with the MAF disconnected. What you will lose is high RPM - but the turbo may mask that somewhat.

It sure sounds like you have no MAF signal and any dealer should be able to test that easily with a PST2 or PIWIS tester.

If it is not the MAF then they should be looking at the connector and wiring or the throttle jacking.

The diagnostic manuals lists:

P0103 - Possible fault cause

-Intake air system on pressure side (between turbocharger and engine) leaks

- Short circuit to B+ (B+ is + 12 volts)

- Mass air flow sensor faulty

- Throttle jacking unit faulty

The reading on a Porsche System Tester should tell them if the MAF is changing with engine speed (intake air flow).

Thanks for the answer.

They claim they have checked the intake system for leaks. No leaks found but DV were gone. DV was changed.

MAF sensor changed 3 times

Throttle jacking unit not checked, just calibrated. Maybe it need cleaning?

Short circuit. Do you mean on the MAF connector wire?

Anyway, just to eliminate. We will also change the gaskets to/from the intercoolers.

Do you mean that the 5525 code is nothing to worry about and that this is not the couse for ABS/PSM lamp and that this is related to the P0103 MAF?

Dealer just called me. They have strong belive that this error is coused by bad/corrupt ECU box. He advised me to try to change it since every other stone is turned.

This will cost me around 900 euro but do i have any choice?

[Oz96Turbo]

Thanks for the post

I picked up my 2002 996 Turbo yesterday

I took to work on freeway today and what should come up, but ABS and PSM failure warnings

And the next lights I restarted the car and codes went

When I checked the on board check feature the warnings had been removed

I hoped there would be something on Renntech about this, and viola a post today on same subject so thank you

I DON'T QUITE UNDERSTAND : why is MAF related to an ABS/PSm failure

Mine is a 996 TT with x50 package

Only mod is after market exhaust

Its run fine the rest of the day and no repeat warning

Its just been serviced two days ago and everything checked perfect

Should I be worried???

Interestingly it had rained in the morning and it was very cool and humid, a bit unuual for Perth recently with the drought

Any ideas

[jipettersen]

Thanks for the post

I picked up my 2002 996 Turbo yesterday

I took to work on freeway today and what should come up, but ABS and PSM failure warnings

And the next lights I restarted the car and codes went

When I checked the on board check feature the warnings had been removed

I hoped there would be something on Renntech about this, and viola a post today on same subject so thank you

I DON'T QUITE UNDERSTAND : why is MAF related to an ABS/PSm failure

Mine is a 996 TT with x50 package

Only mod is after market exhaust

Its run fine the rest of the day and no repeat warning

Its just been serviced two days ago and everything checked perfect

Should I be worried???

Interestingly it had rained in the morning and it was very cool and humid, a bit unuual for Perth recently with the drought

Any ideas

To my undertanding ('m not a mechanic) the communication beetween the MAF sensor are interupted or missing. As a warning the system then shut down the ABS and then PSM.

Most probably in your case it is a bad MAF sensor (common problem). If not, i don't now ? Maybe leaks etc. as you can read above.

If this happens only one time, i will not be worried. But my experience is that this kind of error messages show up time and again.

On my car this is happening every time the boost hit 1 bar , 4-5000rpm, = full trottle. On "normal" driving there is not ABS/PSM light.

On mine everything pointing in the direction corrupt ECU. But early next week i will know.

[Oz96Turbo]

Thanks for the post

I picked up my 2002 996 Turbo yesterday

I took to work on freeway today and what should come up, but ABS and PSM failure warnings

And the next lights I restarted the car and codes went

When I checked the on board check feature the warnings had been removed

I hoped there would be something on Renntech about this, and viola a post today on same subject so thank you

I DON'T QUITE UNDERSTAND : why is MAF related to an ABS/PSm failure

Mine is a 996 TT with x50 package

Only mod is after market exhaust

Its run fine the rest of the day and no repeat warning

Its just been serviced two days ago and everything checked perfect

Should I be worried???

Interestingly it had rained in the morning and it was very cool and humid, a bit unuual for Perth recently with the drought

Any ideas

To my undertanding ('m not a mechanic) the communication beetween the MAF sensor are interupted or missing. As a warning the system then shut down the ABS and then PSM.

Most probably in your case it is a bad MAF sensor (common problem). If not, i don't now ? Maybe leaks etc. as you can read above.

If this happens only one time, i will not be worried. But my experience is that this kind of error messages show up time and again.

On my car this is happening every time the boost hit 1 bar , 4-5000rpm, = full trottle. On "normal" driving there is not ABS/PSM light.

On mine everything pointing in the direction corrupt ECU. But early next week i will know.

Oh OK, its sort of like the only way the car can tell you the MAF is dodgy or hoses or DVs, i get it

Thx for your post

Have had a dodgy MAF with previous C4, interestingly came on during cold humid conditions too.

I wasn't on boost at the time but cruising in 6th gear on Freeway at 100 kph

Appreciate your input

Hope yours gets sorted

Plesase post how it all ends up, I might need to know

All the best

Andrew

[jipettersen]

Thanks for the post

I picked up my 2002 996 Turbo yesterday

I took to work on freeway today and what should come up, but ABS and PSM failure warnings

And the next lights I restarted the car and codes went

When I checked the on board check feature the warnings had been removed

I hoped there would be something on Renntech about this, and viola a post today on same subject so thank you

I DON'T QUITE UNDERSTAND : why is MAF related to an ABS/PSm failure

Mine is a 996 TT with x50 package

Only mod is after market exhaust

Its run fine the rest of the day and no repeat warning

Its just been serviced two days ago and everything checked perfect

Should I be worried???

Interestingly it had rained in the morning and it was very cool and humid, a bit unuual for Perth recently with the drought

Any ideas

To my undertanding ('m not a mechanic) the communication beetween the MAF sensor are interupted or missing. As a warning the system then shut down the ABS and then PSM.

Most probably in your case it is a bad MAF sensor (common problem). If not, i don't now ? Maybe leaks etc. as you can read above.

If this happens only one time, i will not be worried. But my experience is that this kind of error messages show up time and again.

On my car this is happening every time the boost hit 1 bar , 4-5000rpm, = full trottle. On "normal" driving there is not ABS/PSM light.

On mine everything pointing in the direction corrupt ECU. But early next week i will know.

Oh OK, its sort of like the only way the car can tell you the MAF is dodgy or hoses or DVs, i get it

Thx for your post

Have had a dodgy MAF with previous C4, interestingly came on during cold humid conditions too.

I wasn't on boost at the time but cruising in 6th gear on Freeway at 100 kph

Appreciate your input

Hope yours gets sorted

Plesase post how it all ends up, I might need to know

All the best

Andrew

Problem solved.

Installed new DME/ECU today. First test drive with original SW. Everything OK but only 0,7 bar on max but thats about normal i think.

Then dumped the modified Sportec SW. NO ABS/PSM light. 1.1 bar and problem solved.

The only light flashing was PSM because of wheelspin on dry road in 140 kmt

:clapping:

[dxb911turbo]

I have a 2002 996 Turbo and I get the PSM and ABS warnings after I have come to a stop and the car is left idling for a couple of minutes (The warnings only come sometimes). Turn ignition off and then on a couple of times and the messages disappear. It is in the workshop as I write this. Will keep you posted!!

[Chuck Jones]

There have been lots of writeups on this very subject. Most of the guys just turn off the ignition, then turn it back on and see if hte ABS/PSM light clears. Most often, the warning comes on after a hard run, and the general belief is that it has someting to do with the turbulent airflow thru the MAF....but since it clears when you turn the ignition on/off/on again, it's not a big deal. If it continues to light up, or stays on, then it's time to take it to the dealership. I had this problem with mine for a couple months, then it finally came on steady and the dealership changd out the MAF....no further problems.

[dxb911turbo]

I have a K&N air filter fitted. Anyone think that this could be affecting the MAF?

[Chuck Jones]

There are all sorts of previously written articles on the K and N and problems encountered with it throwing CEL's and blowing MAFs......do a search here and on RennList and you'll be reading for a week. Some folks hate them and have spent a lot of money buying new MAFs.....other folks swear by them.....I guess it's the luck of the draw. I have this theory.....leave it stock and you won't have these problems. You don't get much perfomrance enhancement out of a filter anyway. Most of it is hype.