leo993

I'm getting a CEL on my 96 993C4S. The OBDII reader indicates a crank position sensor error. i have consulted with my Indy, he indicates a true crank position problem would result in the engine not running. The car is running fine, and after resetting the code, the CEL does not immediately return. Did a search and could not find a post directly addressing this issue. Has anyone experienced this problem? What was the fix?
Thanks

TRINITONY

lol..not on the 993, but have one right now on my C43, and like the indy said, it results in intermittent starting and no CEL. Never heard of a CPS issue on here before, GL.

Steve Weiner-Rennsport Systems

This may be caused by an intermittent crank sensor connection or a failing dual-mass flywheel.

Time for some additional detailed investigations,...

Mike J

Do you get a rattle when shutting the car off when in neutral with the clutch out? That might indicate a worn DMF, which can oscillate and give weird crank sensor readings....

leo993

No rattle in neutral. Had SAI and top end, as well as clutch done about 2800 miles ago. 53,000 miles total.
Will continue to monitor. Will have the crank sensor connection checked.

leo993

I have noticed that this occurs somewhat cyclic. That is, it appears to take about a 500-600 mile drive cycle for the light to come on. It's happened about 4 times since the rebuild, and I have had the code checked and cleared by a very experienced independent, and by a reputable porsche dealer. Neither found anything that needed to be addressed. Cleared the code and sent me on my way.

Steve Weiner-Rennsport Systems

Since you had the clutch done recently, that connector may have been disturbed, as might be the crank sensor itself. I would confirm the sensor gap (adjust if necessary) and clean the connectors with contact cleaner.

Did they replace the D-M flywheel at this time?

leo993

I do not think they replaced the DM flywheel at that time.

leo993

Thanks Steve!!

Steve Weiner-Rennsport Systems

Bingo!

JMHO,....the D-M flywheel should be replaced anytime the PP, disc, and TOB are changed out, based on experience.

Once doesn't want to do this job over again before 80K.

leo993

Thanks again Steve, I will pass this along to my Indy.

Jeff96-993

Based on what I've read here, it usually seems a failing DMF causes a random misfire code. Never recall it causing a CPS error, but maybe I missed it.

As SteveW suggested, I'd definitely check the CPS installation gap and connections first.