To start, I did try to search but couldn't find my problem. This is a 2000 cherokee sport 4.0. The car was running great as usual but I stopped for a short time then went to back up and it stalled and wouldn't start, acting as if the fuel pump was bad. Upon investigation fuse 11 was blown, replaced it blows immediatly. I unpluged the connector to the fuel pump, still blows the fuse, the ASD relay and the PCM are the other 2 things on that fuse, pulled the ASD relay fuse still blows figure its the PCM. I had to stop at that point, came back the next day to try unpluging the PCM and see if the fuse would blow however now the fuse doesn't blow, repluged the ASD and hooked up the fuel pump fuse holds Jeep runs fine. It was hot when it first quit, 90 deg and the engine was up to temp. Has anyone experenced the PCM failing in this way due to heat. Specificly blowing the fuse? Thanks in advance for any suggestions. Dave

 

The TCM is in that circuit as well. The Dark Blue/White tracer wire that goes from F11 to the PCM splices off (S136) to the TCM, in the wire bundle just after the PDC. Because F11 blowing is associated with selecting reverse there may be an issue with that wire going to the TCM, or the TCM itself.

The Dark Blue/White tracer wire goes through connector C107 (large Black cnnector), located at the trans dipstick tube. Examine the wires going in and out of C107 for chafing, causing a short to ground when the engine torques while in reverse.

 

Thank you for the response, I will look into that tomorrow, I can't get the fuse to blow again so it may be a chaffed wire as you suggested.

 

I checked the wire at the plug mentioned but all was well there. It did get me in the right direction, the cable comming up the back of the engine was between the fuel rail and the firewall the rail had worn through the loom and shorted the blue/ white tracer wire to ground. I think it's the TCM going to the PCM, along with 2 other wires. Thanks for the help. Dave

 

Good find.

Another case of chafed wires at that point.