2002 996TT with 6 speed

UGH!
I thought I had this solved. It had gotten to the point I couldn't drive 1/2 mile before I got the ABS/PSM failure warnings. Replaced the brake switch with a genuine Porsche part and drove the car about 5 miles without a problem! Then, braking hard into a corner the warning came back. Groan... but, I found the right front tire pressure low. Corrected that and life has been good since...until yesterday, that is!

Ran some errands; shut down the car twice before returning home. Thing is, I did NOT pull into my garage and shut down, but left the car idling in the driveway with the car in neutral and the parking brake on. Putzed around in the garage sweeping out leaves and dust, cleaning up some oil, etc. Maybe 5 minutes.
Went back to the car to pull into the garage and the DAMN ABS/PSM warning was displayed!!
WTF is going on???

 

Any recent adventures within the world of potholes...an alignment maybe the way.

 

Nope, not a one.
I just can't fathom why a non-moving, idling car would suddenly trip the ABS/PSM warning.

 

MAF sensor been replaced recently? Or ever?

 

Hmm, not in the 8 years I've owned it!
Anyway to test/confirm it's bad? Or, just have to buy a new one and hope for the best?

 

Trouble codes?

 

OP - Do you have a Porsche-specific code reader? ABS and PSM lights are a great Whack-a-Mole situation!

 

Mine popped on randomly and I just happened to have a scanner in the car last time it happened, and managed to pull the following codes while the error message was still on; cleaned the maf sensor and they haven’t come back since…

not saying that’s what fixed it….but it’s promising so far.

 

Unfortunately, I do not.
Just removed and cleaned the MAF (there is a very mirrored plate that looked dirty in the sensor). Contacts and glass diode looked clean and well crimped.

 

When I got the error, it was a wheel speed sensor. It is an easy fix but you need to know which one because there is one in each wheel. It can be anything...You need to scan it with a proper obd2 reader ..

 

Thing is, the code showed when the car was SITTING STILL...it was fine while I was driving! That's the part that is weird; hard to see how it could be a wheel speed sensor.
But, I guess it could be the MAF

 

Please get the car scanned and report back with the trouble codes. Speculating with minimal info at this point in time is unlikely to resolve the problem.

 

Well, it seems like that could be a waste of money given what I've researched so far on this ABS/PSM issue. As an earlier poster stated, pretty much a Whack-a-Mole situation. Take a look at @e30rapidic 's post: he had FOUR different codes! Only one pointed to the MAF! Which he cleaned and it hasn't come back. So, I've cleaned my MAF and I'm going to drive it a bit and see if it comes back.
Agree that it's pretty much speculation at this point. It just doesn't seem like the codes do a very good job of pointing to the actual cause of this particular problem.

I'd hoped my odd situation of having the ABS/PSM code coming up while the car was just idling in neutral might have been unique enough that someone had seen that before, or at least could narrow down the possible causes.

I'll update with progress/solution. Maybe a few days as the car is down while I fix the driver's side fan..waiting on the part.

 

Thats weird that the MAF would have anything to do with the ABS/PSM.....but these cars are 25 years old now. Hope you got it squared away!

 

MAF issues cause the PSM error because the PSM calculates engine torque from the MAF. If the engine torque does not match what the PSM calculates it throws that code.