Any ECU codes for crankshaft position sensor?

[Mike 99GC]

99' Grand Cherokee 4.0L I6 2WD 47k miles

It started stalling last week. Suddenly cuts out completely while cruising under light throttle or at idle. Will sometimes start immediately but also sometimes takes several minutes of trying periodically. I've also had it not start up after sitting while engine is both hot and cold. Other times it runs flawlessly for extended periods with multiple restarts no problem.

From reading the posts, the crankshaft position sensor seems a likely culprit. I stopped by an Auto Zone store while it was running/starting ok and had them check for ECU codes and it came up "Pass". I suspect they use a pretty generic OBDII scanner though.

Is changing the CPS still worth a try? I thought that the ECU should detect and log a fault if it is really the CPS acting intermittently.

I've read about checking codes with an ignition on-off-on-off-on sequence. Will that work on a '99 OBDII model?

has anyone used the Wells CPS from Autozone? It's only $40 while Jeep gets $98 for the OEM sensor.

Any advice would be deeply appreciated. The intermittent nature of it suddenly stalling makes me reluctant to take it to a shop that may try a shotgun approach and I know it's just a matter of time before it stalls on me in traffic and/or leaves me completely stranded :-(

Thanks,
Mike

[rksnc]

If you do not have a check engine light it will not be a complete failure. But there is a P320 no crank signal and a P0340 no cam signal. You will need scanner to get theses codes. Not a common problem of crank sensor coming and going, that I have seen. This one is not affected by heat as on other vehicles. Have you tried replacing fuel filter?

[Dale Aeppli]

Hi Mike, Check this site out maybe of help Dale
http://www.wjjeeps.com/faultcodes.htm