1996 Jeep Grand Cherokee 4wd v6. Car would not start. We change the crank shaft position sensor and the car started with no problem. 1 month later when we start the car the check engine light comes on and the car run rough for about 5 minutes. I went to Auto zone to have them pull the code and got: P1391 CMO or CKP signal intermittent condition. The ECM detected the actual CMP position disagreed with the expected CMP level. 1. Timing belt or chain stretched or jumped. 2. Defective CMP sensor Is the cam position sensor the same as the crank shaft position sensor? If not where is the cam position sensor at or could it be something else?

SOURCE: 2001 Jeep Grand Cherokee code P1391

I would check to be sure that the timing chain hasn't jumped at all ..

SOURCE: 96 dakota p1391 error

intermittent loss of ckp or cmp.problem is in the distributor.make sure rotor not loose or distributor hold down bolt loose.camsensor on the distributor.also check to see if crank sensor is loose and out of adjustment.

SOURCE: I went to auto zone

one is the crank sensor,m the other is the cam sensor-which was it? you should get the actual code so there is no doubt, if you are having a hard time getting it started, it is probably a crank sensor, if it only manifests itself when running it could be either crank or cam sensor.

Sam Akber

• 1149 Answers
• Posted on Sep 12, 2011

SOURCE: i have a jeep grand

I would change the TPS throttle position sensor and the Map/MAF are you sure its not the mass air flow?. I think your computer is fine it could be have a loose ground issues but computers dont go bad.