magelin

I bought my first Porsche a couple months ago, an '02 996tt

Within a minute or so of driving it will throw up a ABS light and a PSM light, sometimes it will also throw the check engine light.

I ran the durametric and came up with the following.

4206 Front Left Speed Sensor - Signal Implausible
5525 Incorrect data transfer with DME master control unit

I also got P0103 Porsche fault code 115 - Hot film MAF sensor

When I bought the car the seller told me something about a cable needing to be replaced it had come off or something in the front left wheel connecting to the brakes, he said it was a simple fix but he never ordered the cable/sensor. I am no longer in communication with him and never got a good answer when questioning it.

This weekend I can pull the car out and take the wheel off but have no idea what I would be looking for.

Last week I took the MAF out and sprayed it down with MAF cleaner but looks like I still might have an issue with P0103?

Thanks

"02996ttx50

cleaning mafs is.. well.. it works.. or not. new mafs tend to work well. look into the oem wheel sensors at suncoast/pelican/sonnen etc etc any pcar junkyard.
you probably need one.. ( or two lol )

as to mafs? i put enough power thru it, that it freaks out from time 2 time. i buy refurbbed mafs on ebay for $70. it's a diode. don;t get it twisted

gl with it

MechanicalEng

Its an 11 year old car, just get a new Bosch MAF, my car is an 02 also and I just replaced it 2 weeks ago, I had the same PSM/ABS light come on during WOT, the MAF costs about $270... after replacing the MAF the light never came back on

wross996tt

I have said this many times before, but if the MAF is fried, no cleaning can help it. My theory as to What usually affects the MAF is the airflow over the sensor. If this becomes overly turbulent, the sensor can have voltage spikes and fry the electronics. It is likely the sensor can get contamination on it (due to inadequate filtering of the air). A CEL will be triggered when the readings coming from the MAF sensor do not fall between the specs. of the DME parameters.

John McM

Check out my thread on the same problem with the Front Left Speed Sensor - Signal Implausible. It has a check list and shows how I resolved my problem. I needed to buy a harness repair kit and have it fitted. My car shows no faults since the repair, however I burned some needless money on mechanics and a sensor replacement before I fitted the repair kit. Good luck.

FWIW: In my travels I discovered this on the Net. I'll record it here so others have a diagnostic path.

ABS / PSM gauge light appears for no apparent reason.

Possible Causes:
•A wheel came off the ground, wheel hop from accelerating quickly at a low speed, or you hit a pothole (Solution: Turn off the car completely, then turn it back on. The ABS/PSM light will clear itself if this was the case.)
•Failed Brake Sensor (Solution: replace brake sensor approx $20.00)
•Failed or damaged wheel speed sensor (Solution: check datalog codes for left or right sensor failure, swap left and right sensors and see if the failure moves to the opposite side. Replace if code states failure moved to opposite side. Leave sensors alone if code doesn't change.)
•ABS Ring on Axle (Solution: clean the ring)
•Bad Wiring Harness (Testing: Run double 16ga wire from wheel speed sensor directly to ABS box and check for code to clear itself. Solution: Order repair kit and fix harness.)
•Bad ABS Module (This is expensive and should be your last resort. Solution: Repair ABS Module ABS Repair Company

"02996ttx50

+100. story of my ( maf ) life! i've been meaning to ask of you.. since you know your codes! do you know what might be the cause of a p1101 "definition not found" code from a simple obd reader? maf related though.. no? ( sorry inappropriate threadjack sorta.. ) i think i will pm. sorry

Macster

P1101: Input variables, charge measurement - Below Limit, Input variables, charge measurement - Above Limit.

While MAF is not named the phrase charge measurement points to the MAF.

As an aside error codes that begin with a 1 as in P1101 or P1XXX are manufacturer specific.

"02996ttx50

awesome. not sure i'm any clearer.. but my gut says "maf related" but thank you macster

wross996tt

Just for the record:

P1101
594 Input variables, charge measurement - below limit
594 Input variables, charge measurement - above limit

Possible fault cause
♦ Heavily soiled throttle
♦ Throttle damaged
♦ Mass air flow sensor

"02996ttx50

i figured you'd know. thanks. dirty throttle body was my next guess and we shall see. thank you gentlemen.

Bjarne Kastanje

Hi, I have a 02 996 Carrera.

Just bought the car, just had a large service on it (120 000 km), I got these error today, so I got quite scared. Switched the car off started it again. Drove for a while, no errors. Researched a bit on the web, people talking about MAF and sensors. Got out and took an other testdrive, the PSM and ABS lights came on again. Parked shut it off, started again, let it run for 5 minutes, no lights came on when just on idle and not moving.

Did you fix it? Please share what you did to mend the situation.

John McM

First advice, don't panic! Second piece of advice is to get the computer read at a mechanic so you have a starting point. Then you can research and diagnose more efficiently.

Bjarne Kastanje

Thank you John McM. i will take it to get a computer read. I had another go with the car this evening, no errors. It has been raining very heavily the last couple of days and I have not driven the car at all until today. So I was thinking that maybe the MAF senced that there is too much moisture or something. And when I say heavy rain, I mean really heavy, pluss the car (unfortunetly) is not under a roof. Can this be a possibility? Have been thinking about the rear air intak, there must be some water accumulating in the air box underneath.

John McM

I think that's unlikely as Porsche design for heavy weather conditions. Once you have the fault read out from the computer you will be better placed. Until then you could drive yourself mad thinking of all the possibilities. I personally have found the ABS PSM system the most likely to fault. Some are very occassional, some are persistent. You need to fix the latter ones so you can drive your car with confidence.

Bjarne Kastanje

I think I fixed it. Two weeks ago I bought a can of electro cleaner, took out the MAF, sprayed on the metal bits at the sensor end. Let it dry for half an hour. After startup I acctually got the ABS/PSM failure again error message. So I thought %"#¤, well that did not help. But the second time I drove, it did not appear, and has not appeared since. So I guess it is fixed. I love it when the quick fixes work. Have searched the web for possible solutions, and I saw a couple of forum entries stating that the PSM system is very sensitive to voltage spikes, and since the MAF is Connected to the PSM system this might happen.

I did get an error reading, which was acctually did not show anything, not even my airbag error.