where is 1991 Jeep Cherokee Engine Controller?
Welcome to JustAnswer.com! My name is DriveFast71(Ron) and I will do my best to answer all of your questions completely and accurately.
The engine controller is located in the engine compartment. It is mounted next to the air cleaner housing, next to the inner fender.
Would this be responsible for the 30amp EC fuse popping? There is obviously a short, but the symptoms are weird. 1st symptom: 1 week ago no power to the coil while cranking. Could crank indefinitely w/o starting but as sson as i quit cranking it started.2nd symptom: 3 days ago starter became intermittent. Eventually got it going several times.3rd Symptom: After getting it started 2 days ago, I drove 1/2 bock and it quit. 30 Amp EC fuse blown. I replace the starter (FAIL) and the ignition switch (FAIL). That is why I now question the ECM. What do you think?
If the ignition switch wasn't the problem, then yes, the next step I would take would be to look at the ECU and the wire harness. Make sure the harness is tight and seated correctly. Look for any signs of "rubbing" on the wire harness. Inspect the harness for any wires that may be touching each other or grounding out to metal.
OK. I am also thinking of eliminating the fuel pump wiring as the culprit. Is it true that the fuel pump would not function if there was a short in the wiring to it? Because it is functioning I would tend to eleminate that wiring as a possible short.
Correct. If there was a short to the wiring of the fuel pump, it would not run.
Good. You are the first person able to answer that for me. I am also eleminating the Transmission controller, because the tranny had no symptoms or mis-shifts etc. Like you said that leaves the ECM and the harness inside the engine compartment. I am clueless when it comes to using a tester on circuits, being more mechanically inclined, so I usually just start replacing stuff. Any way to test the ECM w/o replacing it?Can I still ask q's after hitting accept?
Unfortunately, due to the age, i'm not seeing a "testing" procedure. Here's what Jeep says:
No specific procedures are provided to diagnose the ECU by itself. ECU failure is determined as a result of a related system failure.
Like I say- inspect that wire harness completely. Most commonly, there will be a loose or broken wire at the harness as it plugs into the ECU. If not, then somewhere in the harness there is a "rubbed through" wire, or a wire touching metal, or two wires touching or even a faulty ECU itself. From here on out, unfortunately, it's just a lot of digging and visual checks.
Got it. That all makes sense.
Glad I could help. Good luck to you. Have a great day!
Where would be a good place to get the wiring diagrams?
Oh boy... good question... i can *TRY* to see what I got... but no promises. Can I get back to you in the morning, as I was actually just leaving for the day...
Yes that would be fine.
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Great, thanks for all your help.
You're welcome. Have a great day!