99 C4

I have a 99 C4, and this weekend I went for a drive and my ABS light went on along with PSM/off. I did not do any hard braking or anything like that, It just went on during the drive. After pulling over and re-starting the car, the light's went off.
This is the second time this happened this month, eventhough the lights go off after re-starting, I wanted to know if anybody experienced this, or has an idea of what might be causing this.

MadCow

Does the light come back on after some forward motion? I had this happen to me (ABS light) on an Acura and it turned out to be one of the ABS speed sensors.

99 C4

It has not come back on more than once during a drive. I recently upgraded my air intake and needed to transfer the MAF sensor from one intake to the other. I was very delicate in the process. The reason I mention the MAF, is because i saw some posts relating the MAF to the ABS/PSM issue.

Armando Ramirez

Ok this one I have had LOT-O-TIMES...have had the sensors replaced......still happens every now and then....but I have noticed in never happens in the summer....I'm not sure where you are but I did get this explanation once and it kind of makes sense given mine has come on while pulling into a parking space or after just starting the car and moving slowing in a parking lot......it does not seem to be realted to hard driving....I was told by someone that these sensors have been known to send faults due to static discharge....which is inline with when it has happened to me here in fl as it seems to be that time of year when I start getting shocked everything I get in or out of the car. Like I said I got this like 7-10 times took it in and the sensor moved aroudn the car that it said was bad....but I have never had a problem with the ABS OR PSM.....have them check the harness just to make sure...but that was never my problem.

TT Gasman

A bad MAF will present this way.

wwest

Clean and tighten the battery post connections and if that doesn't work replace the battery.

m5guru

After taking delivery of my "new to me" 2002 C4 Cab and driving it around for about a week, the same thing happened to me. First happened every few times I started up, but then progressed to every time I hit the road. After the first application of the brakes, the ABS/PSM lights would come on. Other than the fact that there was no ABS or PSM, everything else seemed to work fine.

Luckily, I still had warranty left on the car, so I brought it in to a local Porsche dealer and had them check it out. It was indeed one of the rear brake sensors which was sending the error code and it was replaced. No problems since then (about 1000 miles).

However, just a week or two ago, the Airbag light has been coming on! I think I'm going to have to look into an extended warranty if something is going to fail every month!

David

chsu74

Searching for an answer here. Went for a drive after being away for 4 weeks on a business trip today.

I am getting more frequent PSM and ABS light coming on coasting after hard acceleration. It does go away after a restart. Anyone have pinpointed the cause?

I have a new MAF with approx 20K miles. The alternator shows normal charge.

Renntech search recommended the brake light switch will look into that for $13.00