Crank position sensor (CPS)

JOHN S CROWE

MEMBER
1994 JEEP WANGLER YJ
4.0L
6 CYL
4WD
MANUAL
250,000 MILES

I installed a new CPS two weeks ago and it failed yesterday. I put one on this morning and it worked initially but quit working after a couple of times of starting/stopping the engine. I replaced the CPS again and had the same results. That is three. What could be causing this?
Thanks,
John S Crowe

1 Reply

CARADIODOC

MECHANIC
33,864 POSTS

There are two common things to consider. You have to determine how the circuit failed first to know how to solve it. The first is there was no spacer on the end of the sensor to set the critical air gap. That can cause a crank/no-start, intermittent stalling, or a broken sensor. The second issue is there is nothing wrong with any of the sensors. First we have to rule out wiring and connector terminal problems. To verify that, reinstall one of the older sensors, then see if the engine starts.

You did not list any symptoms or observations, so I can address that. You also did not say how you are determining the crankshaft position sensor has failed. Diagnostic fault codes often do not set for a failed sensor right away or just from cranking the engine.