2000 Cherokee - no spark

[birchlakeXJ]

P1391 = Intermittent Loss of CMP or CKP Loss of the Cam Position Sensor or Crank Position​

sensor has occurred.
SO, yes you are correct... it seems you are on top of the problem...you must have a intermittent sensor, sensor connection, or bad wire somewhere between CMP, or CKP, and PCM. Try wiggling the wires in each area with motor running to get it to stall.

Yup, I'd trust where the code is leading you. Crank sensor or cam sensor circuit. That includes sensor, connector, wiring.

You really should start some testing here.

Both cam and crank sensor can be tested with a meter. Start there.

 

[winterbeater]

Check for 5V power supply at the crank sensor (CKP) plug. Then wiggle wires to see if this changes. If no current, wiggle to see if it starts to get 5V, etc.

 

[steveybass]

I have a powered multimeter. How would I perform this test? Can I do it with the engine not running but with the ignition on?

 

[winterbeater]

Ignition on, not running. Meter on Volts DC. Put the black lead from your meter on a ground. The red lead should be able to pick up 5V in one of the three sockets in the wiring harness. It will be the one with the orange wire. The brown/yellow is the ground.

 

[steveybass]

Question. In checking ohms in a cam sensor and a crank sensor, what should the reading be if it's good? Some people say "infinite" - what does that look like on a digital meter? I have gotten readings of 0.00 and 7.5 on the cam sensors and 0.00 and 15.5 ish on the crank sensors. VERY CONFUSING!!!

 

[steveybass]

Wups. I meant digital multimeter.

 

[jordan]

grand cherokee 2000 3.1 turbo diesel

 

[jordan]

hi there i have a big problem after changing the battery on my 2000 grand cherokee 3.1 turbo diesel the engine is not starting ,all gauges work fine,it cranks but wont start,i called a car diagnostic guy he pluged his computer in the ecu connector and nothing the ecu is not communicating the same with the code reader,what is be the problem

 

[joe_peters]

grand cherokee 2000 3.1 turbo diesel

hi there i have a big problem after changing the battery on my 2000 grand cherokee 3.1 turbo diesel the engine is not starting ,all gauges work fine,it cranks but wont start,i called a car diagnostic guy he pluged his computer in the ecu connector and nothing the ecu is not communicating the same with the code reader,what is be the problem

Hello Jordan.

is the XJ Cherokee group, so you won't get much if any help here.

Try here at the Grand Cherokee association: http://www.nagca.com/

Good luck.