How I fixed my 1997 Grand Cherokee
by Hugh_Jass70 - 2/9/12 10:25 PM
Most mid to late 90's Grand Cherokees have bad solder joints in the PCM (Computer behind the radiator overflow on the passenger side firewall). It affects the grey wire which is the ignition coil ground controlled by the computer. You can gently wiggle the inner most PCM plug (closest to the center of the vehicle) and the engine will stumble or stall. You can also check for codes and see if it has a P0351 in memory. When you buy a supposed "remanufactured" PCM all you are getting is a used, cleaned PCM. Since many Grand Cherokees experience this problem, it is a gamble if the used computer is any good. My Grand Cherokee started to stall on me on a daily basis. Sometimes it would immediately restart, other times I would have to unplug and plug the inner most PCM plug to get it started. It became very scary to drive. It is temperature related as the circuit board flexes. I fixed my problem by making a clamp to gently press the PCM and three plug in connectors together. Go to the hardware store and buy a steel bar approximately 1" wide by 1/8" thick by 20 inches long. Cut two identical pieces approximately 8" long with holes on each end. You will put one bar behind the PCM and the other in front of the three connectors on the front of the PCM. Use two 4" lag bolts and two wing nuts on the sides of the PCM to clamp the bars together. It can be a tight fit and the bolts should come in from the back side of the pcm so the wing nuts can be tightened from the front. Don't try to over-tighten the wing nuts. You don't want to break anything. My Jeep hasn't stalled once since I did this. It can be made for under $10.