I've been away from the board for a bit but thought I would throw this out to see if anybody has experienced something similar. I'm driving to the Porsche dealer to pickup some parts to change my oil this weekend and on the way the PSM and ABS lights come on along with the message "drive to the dealer...ching ching". I get to the dealer, turn the engine off, remove the key and figure what the heck...I restart the turbo and poof!, the PSM and ABS lights don't come back on and there's no message in the memory. The Porsche tech, Shawn who knows his stuff with turbo's, ran the computer on it and could not find any error messages or a problem that might have caused this. He put a new MAF sensor and throttle body on about 3 weeks ago due to the engine dying between 3rd to 2nd during a slow downshift. So, what would cause these two error message and then disappear when the car is restarted? Shawn had no idea what might have caused it other than to mention that they saw the same problem with the 993 turbo's.

 

Those codes are often related to MAF, but not always...there are a number of possibilities:
1. could be the MAF is not connected completely/correctly
2. could be a sensor
3. could be plugs/coil packs
4. leaks somewhere (possibly related the the TB install)

I guess if there were no codes...don't worry about it until it happens again.

 

I got the same thing, but the PSM and ABS lights came on at the track. When I turned the car off and then turned it on the lights would be gone, but when I went over a dip the lights would come back on. When they ran it using the computer it came up that it was a bad ABS and PSM senor on the front passanger side. When the sensors were replaced the problem went away.

 

Same thing happened to me a few times and I know exactly what it was each time. Depending upon the road, you'll find those grooves on the edge or middle of the road that when driven over make a vibration and large sound throughout the car (assuming to keep drivers from falling asleep at the wheel). Anyways, I think when you drive over that at speed the abs freeks out, and then the psm also freeks out. Its happened to me twice when passing people on this one section of road that has it in between lanes on the passing dotted lines. Hope that helps.

Bojan

 

I had the same problem. No other lights and no errors logged in the ECU and the car ran fine. It was the ABS/PSM wiring harness' near the front wheels. The wires had become frayed.

 

This is wild! So I need to stay away from titty bumps (as my wife calls them) and grooves in the road but what about that boom box car that's maxed out on the bass with the trunk and rear panels vibrating like there's no tomorrow, how do I avoid them?

Just kidding...this is great information. Very glad to hear that this is not a serious problem. Is there anything that I can do to check to see if the wires are loose or frayed near the end at the front wheels before taking it to the dealer? If so, where does the wire terminate and any idea what color the wires are? Thanks for all your help.

 

Had the exact same issue today! Tech said the diverter valve hoses were loose and the MAF meter was bad. Seems like a common issue.

 

When the psm abs light is on, check to see if your brake lights work.

 

Sounds like this could be coming from a number of differient areas. Did your brake lights not work when your PSM/AMS lights came on? So far my PSM/ABS lights have not come on again since this first happened. Should they come back on I will check to see if the brake lights work. I'm going to be changing the oil and air filter this weekend and will check the diverter hoses for any leaks. The MAF senor was just replaced three weeks ago so hopefully that's not the problem. Do any of you have more information (picture) as to where to PSM/ABS wiring harness' terminate are the front of the car to check it for fraying?

 

If your alignment is off, that might happen too...was at the track and however it happened, the right rear alignment got way out of whack...on the drive home the steering was pulling and the the ABS/PSM light went on.

 

It was aligned about 3 months ago and I have not tracked it since. It's not pulling to either side...pretty much runs straight. The ABC/PSM lights have not come on again since this first happened. Maybe just a gremlin running around. I'm going to go over the car this weekend to see if any wire connectors or loose or frayed as well as checking the hoses. Maybe I'll get lucky and find the problem.

 

that happened to my car couple of times too and went away after i restarted. so do you advise to take it to the p shop or just stay away from those titty bumps?

 

Well...you can avoid the ******* if you want...as for me, I'll be looking for them ever chance I get

As for taking to the P shop...naw, I'm going to drive mine until the friggin lights come on and stay on. Anyway, its more chanllenging to drive a turbo with the PSM not functioning don't you think?

 

This just happened to me. I'm taking tjj7ff's advice and holding off on going into Porsche. Car just had its 2-year service, so could be related, but I am going to wait it out.

 

I had this happen two days ago, which is the second time that this has occured. I was stopped at a light and noticed that the RPMs were fluctuating from 1,100 to 850 RPMs. Both warning lights came on during this period. I shut the engine off and restarted it and both lights did not come back on. The engine is still fluctuating in this RPM range. I also had a check engine light come on last week. I took it to the dealer where they found a code referencing that something was wrong with the idle? I didn’t have time to stay have them work on it. They reset the code and told me to make an appointment. The check engine light has not come on since. I guess I just need to take it down and let them go over it after the lights come back on, which I’m sure they will. This is getting to be a little fustrating.