badger15

Hi there, I just picked up an 01 996TT with 72K. I had the car checked by the local Porsche dealership and they said it needed nothing, one of the cleanest cars they have seen. I've been very happy with it but have been getting a periodic PSM/ABS message. At first I thought it was because the battery was junk, but after replacing it I still sometimes get it. Happens maybe every 3-4 times I drive the car and goes away after I recycle the key. Also, happens more often when I am actually braking.

Thanks for any help you can provide. I'm excited to become a member of the 996TT community.

mpclimber

MAF Sensor needs to be replaced.

Condor Man

I had this happen when I had new rear rubber with older front rubber in different brand.

As soon as I changed the front the problem stopped happening.

Good luck with the car!

Kevin

Welcome to the forum..

90% of the time it's your MAF..

However, it can also be your brake switch..

vincentdds

If it's your MAF sensor the warning light will not go away after recycling your key. See if your brake light works when this happen. It could also be your ABS sensors and/or the size of your after market wheels and tires. Mine comes on once in awhile upon going reverse.

mpclimber

I've seen the ABS/PSM warning light go away when you cylce the key on a dead MAF car.

msligar

I have an '02 and had this happen only once when I hit the brakes hard at very high speed. I cycled and it went away however was concerned that something might be wrong. I am curious if this would be the same root cause.

TT Surgeon

Once when they aligned my c4s it happened, the bumped one of the abs sensors. Could have happened during your ppi.
C

Kevin

msligar, your ABS, system was activated with your hard braking. Normal for your system.

adam_

what brand and size tires are you running, front and rear?

badger15

Thanks for all the responses. All my rubber matches and I am running stock wheels/tire sizes. This leads me to believe that I need a new MAF. I will be ordering one soon....hopefully it will take car of the issue.

vincentdds

Best price for MAF.
$225

badger15

Hey guys, I wanted to update you on this issue. I purchased a MAF from Kevin Matwichuk, he sent me an email with a MAF for sale after I posted this question. I just got the MAF and installed it. The first drive, only about 5 min, the car ran great. On my second drive, the issue returned. I am experiencing a surging idle and getting the PSM/ABS message!? Any ideas? Thanks for your help, I will answer any other questions you guys may have to the best of my ability.

Thanks again.

Kevin

Have you scanned the codes at a Porsche dealer since the MAF install?

A bypass valve could/can be failing, a small pressure control line might be off. Have you installed plugs?

badger15

The car has not been scanned since Fri.. I have not replaced the plugs, although the 60,000 mile service was done. The car is completely stock and is a tiptronic. The symptoms occur generally at idle. Although, I also notice periodic hesitation during acceleration. Are these symptoms consistent with a faulty bypass valve? The dealer that did the PPI, and my local dealer both mentioned the throttle body. The 1st said service it to correct the idle. The local dealer said the code mentioned it. What's my next step? Is there any way the new MFA is corrupt? As always, thanks for your help.
Grace and Peace,
Mitch