judd944

clicking the button does nothing. A search did not yield much.
I was driving last night and as I pulled onto an interstate the light came on. I am not sure when exactly but I turned on the cruise control and used my left indicator just before it turned on. I tried to turn the car on and off a few times and it is still there. no other lights are lit up on the dash.

Any ideas?

Chuck Jones

Go to Autozone and borrow their code reader....see if it will record an error code and go from there. When is the last time you had your brakes checked?

judd944

I have an OBD II reader. I can hook it up but the check engine light is not on. I just drove it again today. the light is still on. The brake pads have some life left and they have not tripped the wear sensor yet.

LVDell

PSM is not emissions based (OBDII). You will need somebody with a PST2 or PIWIS more likely the dealer.

Riad

Is your ABS light also on?

Could be a steering sensor fault.

judd944

nope, ABS light is not on.

I will keep an eye out for other lights turning on, some of the reading says that if the PSM light and another light it could be the MAF.

LVDell

Where did you read that? By the way, what is your car model and year? Which PSM light is on? The ! or the PSM OFF? Do you have an OBC that is displaying any further messages?

Loren

Check to see if your brake lights work (you will need a second person).
If they don't then you have a bad brake light switch.

LVDell

Good one Loren. Actually if you do this in your garage with the door down you could see if you brake lights illuminate (or just back up to a window at the front of your house).

Doug Donsbach

Some other things to check:

- Fuse E10
- Activate / release the parking brake several times (switch might be sticky there)

Otherwise, diagnosis is very involved as there are about 100 pages in the manual devoted to PSM fault identification.

judd944

Fuse E10 is still OK. I actually checked all the fuses that had something to do with PSM. they all were fine. The parking brake is functioning properly. (the light goes out when I release it)
Brake lights work but I am getting the wife to make sure they ALL work.

judd944

2001 986S

PSM off is what is lit up. the "!" light is not on.

I read it is common on the 996tt for the PSM light and the ABS light to come on with the failure of the MAF. rennteam or 6-speed. I cannot find it now.

I have a friend in the Porsche club that has this I will go try it tomorrow night and see what reads out.

judd944

PSM is not working. I can spin tire all I want now.

LVDell

Why in the world would PSM/ABS light up for an emissions based offense? That makes no sense. The reason I asked what lights were on was b/c there are 2 PSM lights and both serve very different purposes. Sounds like your PSM is malfunctioning since it does not engage. This sounds like a definite trip to the dealer or your local indy that has PST2/PIWIS.

Todd Holyoak

As everyone else states, you need to have the ABS/PSM system errors read out by a proper tester (PST/PIWIS/Durametric)
According to the factory manual:
There are 3 warning lights for the ABS/TC system.
1) The triangle warning lamp is the info lamp for FDR (I assume an acronym for TC), the ASR and ABD systems. If FDR, ASR or ABD function it flashes.
2) The PSM warning lamp which illuminates if:
The FDR is faulty
ABS is faulty
FDR is switched off
or the ABD is being activated
3) ABS warning lamp, illuminates with ABS fault

The only errors i know of that will deactivate only PSM is low brake fluid level, transverse accel sensor, turn sensor, and certain pressure sensor and booster pump sensor errors. All other errors result in the loss of all the PSM, ABS and TC functions.