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goldenruleser, ASE Certified Technician
Category: Jeep
Satisfied Customers: 210
Experience:  31 years Shop owner ASE Sears Automotive Training previous experience working on jeeps
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1998 Jeep grand Cherokee 4WD 4.0 (Laundry List) Symptoms increased

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1998 Jeep grand Cherokee 4WD 4.0 Symptoms =increased stalls and misfires over last couple of months. First thot was tranny which was serviced and refilled - drover better, but still stalled. Mornings (cold start) no probs for 5 mins, then stutter or stall. Sometimes restart is instant with key turn. Dash guages turn off. One time dash was powered off (all guages off Pwr windown wouldn't work) yet truck was running smoothly. That hasn't happened in some time. Some days no problems at all-electrical? (Have Replaced: Coil, wires, ditsributor cap and rotar, ignition switch, checked fuses, and prep'd to replce the ignition pick up. Sensor? Codes checked and cleared and it is telling me that the coil is reporting but it was just replcd? newest= Left turn Sig on dash remains lit if HDlights are on and when engaged left sig is rapid&both fRNT/BK lights are working properly. Checked battery/alterntr=okay. wife told me she heard liquid squishing levld off low coolant ok
Please tell me 2 things with the key on does the check engine light stay on steady ? What are the past & current DTC codes you have for the vehicle. Thanks Dave
Customer: replied 8 years ago.
There is no check engine light. If I just turn the key to the on position...It remains lit steady and eventually turns off with the rest of the lights. Normally it ust stalls out. General current DTC codes = Coil and map sensor. old codes were specific to the tranny: Cam sensor and stop senor reporting too low. After tranny serviced and sensors replaced codes cleared. I am going to go over and have the codes checked right now so that I have the actual #s for you
You lost me does the yellow check engine light come on steady with the key on engine off ?
Customer: replied 8 years ago.

Key on engine off - all service lights turn on - ABS, etc... they all slowly cycle off check engine light is steady and then shuts off in about 10 - 15 sec

CPU Codes:

P0108 Map Circ High Input

P0320 Ignition engine speed circ malfunction

P0351 Ignition Coil primary and secondary circ malfunction

All your problems are do to poor/bad body frame grounds, Ground points G100,101,103,104,105,106,109,300,&304 will need to be checked for corrosion & tight connection to the frame or body. I have included some pictures in the links below that will help locate the ground points.Thanks for being a justanswer customer Dave
Customer: replied 8 years ago.
I am having trouble locating all of the grounds... I think that I have found two and cleaned them. Is it possible that the grounds are shared in the CPU? Or will all of them be bolted to the frame or firewall?
Yes it is & I am sorry but most of the wiring diagrams don't usually give good cut and dry ground point locations it's more common sense & experience to find the location some of them Dave
Customer: replied 8 years ago.

I appreciate your suggestion, but my problem was not the grounds. After countless hours of checking the grounds, the voltages, the fuses, the relays, the sensors and replacing hundreds of $ in parts - I have finally found the problem.




In a 98 Jeep Grand Cherokee it is located behind the coolant reserve tank, and it appears that the electrical connectors pull down over time causing a bad connection. It randomly connects and disconnects and causes all sorts of problems with reporting codes for the system. After a while, I thought that there had to be a problem behind the COIL since I had already replaced the ENTIRE ignition system (coil, wires, plugs, rotor, cap , Ig switch, distrib, etc...) but the PCM was reporting a coil circuit failure. I had even suspected that the security system might be the problem. My stalls slowly increased over time and were worse in warm weather (I live in FL) but didn't follow a regular pattern.


Anyone who might be reading this: The easiest way to test if this is your problem is to wiggle the harness with light pressure at the PCM. I ended up wedging a spacer between the front of the PCM and the underside of the electrical connector (which is "L" shaped) to push it up in to place and then fastened the spacer to the PCM with a large ZipTie.


I did a search on the web after I figured out what the problem was and found the following link about 3rd from the top - they have alternative suggestions and credits (I wish that I would have found this post $1000.00 ago)


"The Fix: (as unbelievable as this sounds, but reported to have almost a 90% success rate from around 45-65 people)


Then try to start."

This is apparently a relatively COMMON problem on aging Chrysler products with this type of electrical connector at the PCM. I hope that this information is helpful to others out there who may find this post - God is good and Angels are real! Thank you for watching over me -Customer11/2008


Hi,Customer,I Glad you found the solution to your problem. Dave
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