JEEP CODES P1391 AND P1398 - 1996 Jeep Grand Cherokee

Both point to a problem with a module rather than a sensor. We have an auto-electrician Expert here and hopefully he will be along. The first thing to do is clear the codes and see if they come back. If they do, you need a good auto-electrician, not a mechanic and not a guy from Autozone.

This tells you what causes P1698.

P1698 JEEP Code - PCM Fault No CCD Message From TCM

https://www.engine-codes.com > p1698_jeep
'P1698 JEEP code possible causes · Faulty Transmission Control Module (TCM) · Transmission Control Module harness is open or shorted · Transmission Control Module ...

This tell you all the items that can cause P1391.

P1391 JEEP Code - CMP or CKP Signal Intermittent Condition

https://www.autocodes.com > p1391_jeep
'P1391 JEEP code description ... The Powertrain Control Module (PCM) monitors the Camshaft Position Sensor (CMP) Or Crankshaft Position Sensor

..

Error Code P1391 is defined as CMP or CKP Signal Intermittent Condition. It refers to intermittent conditions in the CMP (camshaft position sensor)

Check the fuel filter,nozzles and clean the injector mouth

What kind of Jeep?

For some reason you question has been duplicated several times, so I will answer this one.
Code 1391 may be a problem with the ABS system, the other three codes are concerning the first 3 coils. Your engine has direct spark so each cylinder has its own coil.
I would clear the codes and see which ones come back after a test drive. If the three coil codes come back the coils would need to be tested.

http://www.jeepforum.com/forum/f9/p1398-crank-sensor-issue-i-cant-figure-out-647960/

The codes you mention 301-302-303 are all misfire in the respective cylinders. you should replace the coil, while you are at it also verify the condition od the sparkplugs.

I am having the same problem, did you solve it?

Mike

The van has several issues... I may not cover all of them here:

1. The rpm tac wire is not seated properly at the tranny.
2. The "ground" is not making a good connection; maybe the ground strap was removed and not replaced. Purchase a "ground strap" ($12) at an auto parts store (AutoZone?) and connect it from the engine to a convenient location on the chassis .

That should clear the rpm and the ****.

Comments anyone??

on a 2003 jeep liberty sport 3.7 liter getting codes of p0340 and p1391. its a reman motor. first 600 miles of break in we had no problems then we did a oil and filter change. we ffirst got the p1391 code and changed both the cmp and ckp sensor and ended up with both codes.