dmw

Somewhat misleading title maybe. My 2002 Carrera 4S has died a couple of times while I’m driving recently. It would restart immediately afterward (although sometimes it took a while to crank). The most recent time/yesterday, it threw a check engine light (code P0335 Crankshaft Position Sensor “A” Circuit). I went to get a new battery, since the old one was 7 years old (just in case that was it) and now it won’t start. It cranks the starter motor but won’t start/fire up. It’s sitting in a parking lot and I’m wondering if there is anything I can do before towing it to the shop Monday. Thanks!

DBJoe996

Well, it told you what is/was wrong - crank position sensor. Every time there is a "cranks but no start", it is the crank position sensor. Maybe as a last resort you could try to reach up there and jiggle the wires. Might be a loose connection.

jdbornem

I'm not sure I understand the question, you already know what the answer is.
Error for crankshaft position sensor != battery problem

dmw

Just checking. I read other posts suggesting that an old/bad battery could throw strange codes and lead to other random issues. I had an old battery. I also read that a bad CPS leads to a rough running engine. Other than a couple random stalls (where the car always restarted) the car ran perfectly. It just seems strange that all of a sudden, immediately after the battery was replaced, the car cranks but won’t start. I thought maybe there was some type of reprogramming (anti-theft?) that had to be done after a new battery. Wanted to check that before leaving it in a random parking lot all weekend and towing it Monday.

DBJoe996

You don't have to do any reprogramming after battery replacement. If the key opens the car and makes it crank, then the immobilizer is working correctly. Have you checked the "new" battery with a multimeter? Who installed the new battery? Are the battery connections clean and tight? Have you checked the fuses for ignition? There are also relays that need to be checked. Also, another source of mysterious electrical gremlins is the ignition switch. Have you ever changed it out?

golock911

Please report back after you replace the crank sensor. And drive on. Good luck!

dmw

Go figure. I went back this morning and Tried e-gas calibration: turn key to the last position before crank and leave it there for 60s, then turn key to OFF and wait 10s. As suggested by this thread: https://rennlist.com/forums/996-foru...w-battery.html. Car fired right up so I drove it home. Turned it off. Started right up again. Car runs fine. No CEL. I’m still taking it into the shop just in case but will probably drive it around my neighborhood a few times this weekend to see what happens.

jdbornem

That's great. I have had crankshaft position sensors act like that before though. The car (not my 996) would die randomly, but still restart. Then one day it just decided it was done and the car wouldn't start at all, in a store parking lot. Towed it, replaced CPS, and everything was fine. So, you may still have a bad sensor. Glad you got it out of the parking lot though!

dmw

I’m pretty sure it’s the CPS. I’m counting myself lucky and taking it in this week.

DSC800

It does sound like the CPS. That sensor is very easy to DIY if you can raise the driver's rear on a ramp or jack + jack stand enough to climb under. It's one connector, one bolt, probably a 10mm. Pelican shows a photo of the location and you can see the sensor through the wheel spokes.

Botsy67

+1 w/ DSC reply... just saw a very good DIY from FCP (Mike Hidalgo) on this CPS, check it out. Looks like you could DIY it if you have a set of ramps or jack-stands, good-luck, cheers...

theprf

Just a note - the crank position sensor's WAY MORE DIFFICULT to get to on a 996.2 Mercedes Tiptronic.
BTW, I have an extra brand new Tiptronic CPS if anyone needs it.

dmw

Shop can’t get it in for 10 days. Is a 2002 Carrera 4S the same install as the video? I have a 4 post lift (mainly for storage) and this looks doable, assuming it’s not more difficult on a 2002 vs 1999 in the video. Thanks in advance.

dmw

Hmm. Looks like you need to take the wheel off, which means my lift won’t be much help.

De Jeeper

Just put a floor jack under the jack point. Do it all the time on my 4 post