I have a 2001 grand Cherokee Limited 4.0 that won't start. It cranks all day. There is no power going to the fuel pump. No spark. The gauges don't work, only the lights. One light that shows say "check gauges" and the other has a no key light. I have tried to get engine codes. One from using the key to turn on and off the ignition. But no codes are brought up. Two I tried 2 different obd2 scanners and both failed to connect. I have checked the fuses. I replace fuel pump and filter. Also replaced the ecu. I haven't replaced the cam position sensor. I don't know if that should be my next step. Or is there anything else I should attend to?

 

Dave and some of the others here are far more familiar with the GC electrical system than me but I'll go ahead and step up with a quickie. If the fuel pump aint working and the ignition is not firing you obviously have no electricity going to them with the possible but unlikely exception that you are dealing with multiple malfunctions at the same time.. Start tracking power on the smaller of the two positive battery cables to make sure you have power on it first where the cable comes out of the battery terminal connector, then down to the power distribution center, and onwards from there. I haven't had any ground problems yet with my 2004 but reading here they are very common on Grand Cherokees so check and clean your body and engine grounds also. I had the same problem on mine and it was simply that the battery connector on the positive cable was getting power to the large positive cable which makes the starter spin, but no power to the smaller cable which powers everything else. Put on a new battery cable end and problem solved. Now the problem may be the same on yours or the lossof power may be further downstream so you just got to get a test light and starting at the battery work your way down until you find it. with multiple systems being dead at the same time most llkely the problem is going to be found in the positive battery cable between the battery and fuse box.

 

All the gauges are powered by output from the PCM (computer) so if you have no gauges, the PCM isn't getting power or not enough to function. After checking the obvious, wiggle the cable plugs that go into the PCM. You may have a bad connection on one of the pins.

 

What's the procedure for removing the power connection at the ECM without damaging it.short or overload? I want to check all my power connections tomorrow.
remove battery first, removed connector and clean and replace? is it a good idea to use a electronic cleaner/dielectric grease before re-installation?
I am having some issues with my 04 Limited V8