I'm a new Porsche owner and have a 2001 Porsche 996 Turbo. I just got the car and after it has been running for a bit when the car is hot the PSM/ABS light come on the dashboard. I have changed the MAF as Porsche told me that was the problem, after I purchased a new one from them it has still not gone away; I also changed the break light switch as i was also told this could be the problem too. I am lost to what the problem can be, when the light dose come on the engine dose not always idle correct and drop is revs up and down for a bit then settles down. Can anyone help with this as i have looked everywhere? I have also looked at the batter charge and when from cold the battery reads 12.5Volts when running the car reads 13.6 volts but dose drop to the lowest at 13.4 Volts
Please help?

Thank you
Any ides would be great

 

Did you clear the pending error codes from the computer after you replaced the MAF?

 

Yes Porsche dealer cleared all faults for me, come back on when left the dealer

 

What are the codes exactly?

Check the wiring harness at the MAF sensor. I have seen wires pull out of the connector, or be damaged in that area. Sometimes it is right at the connector, other times it is further back in the harness (6-8 inches or so)

 

Before anythinh else, check your brake light switch. This is the cause of most ABS/PSM faults.

 

Hi,
I am going to the Porsche dealer today, so will get the fault codes and get back to you.
Also will look at the wiring harness at the MAF sensor and further back in the harness but do you think it could be that? As when i first start the car everything is ok and there is no problems. The car has no idle problems and the car drives fine it is only when the car heats up or have been driving for some time Psm/Abs may come on..

Also have changed the brake light switch with a new one from Porsche dealer and that did not seem to fix the problem.
Thank you
Neal

 

Did you install LED Taillights? Also verify all your lights are working properly.

 

I have Not installed LED lights and i can verify all light are working fine
Thank you

 

Any mods on the car?

 

Hi,
Know Mods all standard..
Thanks

 

Thank you for your updates I have purchased two new speed sensors today and am fitting them in the morning, I did try today but the sensors are very hard to remove after removing the bolts has anyone got any ides? I will up date you in the morning after I have fitted them, Hope this work if not I will replace the Oxygen sensors.

 

why keep throwing parts at it? let the dealer fix it.

 

The Dealer dose not know them selfs as i have taken it to the dealer and they keep throwing parts at it to. Why pay dealer prices for parts when you can get them cheaper your self!!!

 

I know exactly what you are going through i am having the exact problem at the moment.In the morning no psm abs lights after it warms up turn car off then back on again on it comes.New maf sensor brake light switch and still searching.

 

Do you have a 996 turbo? I changed my intake to the EVOM V Flow intake, silicone hoses, AP diverters, AP race plenum. I noticed that the MAF/ABS light came on. I ran a check using my Durametric cable and cleared the code. Then I tested the car again, then after a short boost run, the light came on again. I looked again under the hood and double checked the hose connections just to make sure there were no leaks. I noticed a small vacuum line was off underneath the intake Y collector right before the throttle body. After connection I reconnected the line and no light.