ABS & PSM Failure lights

[erubin]

I just had my failure lights for the pSM and ABS go on. This is the first time I have driven the car since my last DE event 1 week ago. Anybody have any ideas what might be going on?

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[mathism]

My first guess is you are low on brake fluid. Most likely, you wore your pads way down and there is now more fluid in the lines and less in the resevoir. Top off the resevoir and recheck for the lights. Make sure you also check your pads.

[erubin]

Originally Posted by mathism

My first guess is you are low on brake fluid. Most likely, you wore your pads way down and there is now more fluid in the lines and less in the resevoir. Top off the resevoir and recheck for the lights. Make sure you also check your pads.

Thanks for the reply. I checked the fluid reservoir and it was fine. The brake pads are on the low side but my pad wear sensor lights did not illuminate. The error lights have gone off and on intermittently over the last few days. I am going to change my pads out and see if this resolves the issue.

[Porsche Tech]

Originally Posted by erubin

I just had my failure lights for the pSM and ABS go on. This is the first time I have driven the car since my last DE event 1 week ago. Anybody have any ideas what might be going on?

There is a good possibility that the MAF may be starting to go as the traction control feature (PSM) needs load signal from the MAF to calculate how much power to apply or reduce. Usually see some DME fault too. PSM is just a function of power management in conjuction with application of ABS.
You need to get the DME and ABS control modules scanned though as there could be a bad wheel speed sensor or other component that is failing. If the ABS control module is missing a wheel speed sensor signal or itself becomes faulty the ABS light will illuminate and traction control can not function properly. Maybe some trash in an ABS wheel speed sensor from the track possible also.

[JB Lifeguard]

i was reading about this fault on Rennlist (there are many threads discussing this fault). it seems MAF sensor is #1 on list of possible faults, bad air filter is also mentioned.

if you find resolution for this let me know. Mine goes off when i drive on a highway for about 15-20 mi. Driving at low speed through side streets, I can drive along way.

roy

[Mother]

Both ABS and PSM flicker on off but mostly just on and durametric scanner says bad/shorted etc right wheel speed sensor. Cleaned sensor and inside wheel sensor area with no results. Just saying you could check it or clean also.

[JB Lifeguard]

Thanks for the hint, Mother.

I will clean the sensors and see what happens.

I have already cleaned the MAF sensor, with no change. I will check the air filter; due to the symptom, failure only at high speed, it may be that dirty air is shorting the MAF under high air volume flows.

i will post my results.

roy

[erubin]

I will give it a try as well. I am running a Carbonio CIA with much higher air flow. Not sure if this is contributing at all. What is the best solvent to use when cleaning the sensors?

[JB Lifeguard]

I am going to the Porsche/VW dealer to get my wife's Passat back. I will go in and ask the head tech guy and post his response.

[Porsche Tech]

Originally Posted by JB Lifeguard

Thanks for the hint, Mother.

I will clean the sensors and see what happens.

I have already cleaned the MAF sensor, with no change. I will check the air filter; due to the symptom, failure only at high speed, it may be that dirty air is shorting the MAF under high air volume flows.

i will post my results.

roy

To determine if it is a MAF failure you need to get the DME control module scanned and look at the live data for MAF and fuel trims (TRA/RKAT and FRA)
MAF air volume spec: 17kg/hr +/- 2 for 996
MAF hot film voltage: 1.2-1.4V +/- 2v engine running (key on engine off .9V +/-.2V
TRA value should be around 0
FRA value should be around 1

[na011]

I've had this happen to me in two different 997's. Both times it was covered under warranty. The Dealer said it is a switch (~$15 part) on the inside of the car (firewall) in back of & near the top of the brake pedal. The first time it happened (3+ years ago) they sent a flat bed wrecker to pick up the car. The next time (different car & 2 months ago) they said if you still have brakes (I did) to drive it in & most likely it was a bad switch and it was.

[JB Lifeguard]

Ok. News from my dealer. {By the way, if you need a dealer in South New Jersey, Cherry Hill P/A has given me excellent service.}

Last week, i had the turn signal box changed because the turn signal broke. In taking the steering column apart, the airbag clock spring unraveled. The part number is 996 652 211 00. This failure is giving signals that the turn sensors failed.

So, there it is. Who knew, my dealer had the answer.

Since the part is $232 plus installation, I guess I will live it for now.

Roy

2002 C4S

[EastBay]

Originally Posted by na011

I've had this happen to me in two different 997's. Both times it was covered under warranty. The Dealer said it is a switch (~$15 part) on the inside of the car (firewall) in back of & near the top of the brake pedal. The first time it happened (3+ years ago) they sent a flat bed wrecker to pick up the car. The next time (different car & 2 months ago) they said if you still have brakes (I did) to drive it in & most likely it was a bad switch and it was.

yep sounds like the classic brake light switch failure

[Dharn55]

JB Lifeguard - I have one of those airbag contacts if you are interested. I will sell it for alot less than they quoted you. And it is a DIY if you have a little aptitude and experience. There are some posts that have excellent instructions for it. PM me if you are interested.

[JB Lifeguard]

Dharn55

I tried to PM you, but it may not have gone thru.

i would be interested in the part. i will try to find the DIY instructions, but if you have them handy, or the link, could you please forward it.

i got your PM, and if you send me your email, we can communicate that way.

thanks

JB LG