I have a 2000 grand with the 4.0. The voltage regulator was bad but to replace it you need to replace the PCM. I bought a reman PCM and it ran great for about 10 miles then it shut down. Before I replaced it the CEL said high voltage now with the new one it says RF wheel speed sensor signal malfunction, ECU internal malfunction, over voltage, no cam shaft reference signal at PCM, ignition coil primary circuit 1&3 loss of camshaft crank. What the hell is going on? I put the old computer back in so I could try to drive it home and it's the same with my old comp now. Could the new reman have fried all this stuff? I called them and they told me to pull all 3 harnesses and the negative on the battery for 1 hour to reset the comp so I left them unhooked for 9 hours while I went to work and still nothing.

I could at least drive it before the swap and now there is no spark at all.
All fixed, see post #9

 

I would be very greatful for any help at all.

 

Sorry Troy, I'm of no help with electrical issues. I'm sure others will answer with some help.

 

Nobody has any ideas at all?

 

You got me man I wish I had an answer for you. Hopefully someone will chime in soon. But you said you have no spark are you getting power to your coil?

 

Just an aside. My 00 WJ 4.0 has coil packs.

Sorry, I'm not computer smart enough to know about this. Give me a 60's car and I'll run with the best of them!

 

I checked the coil pack and I'm getting power to it at all 6 boots, CPS and harness, computer, alt and injectors. It also has great fuel pressure. I just swapped out the comp with another one they sent me and still nothing. I did find that the CPS hold down bolt was loose and it was flopping around in the block so I tested the CPS with a multimeter and it tested good.

 

Just replaced the crank sensor and still nothing. By the way that is a very easy job. I was told 2.5 hours and I started at 11:54 and finished at 12:17. It still cranks like nobodies bussiness but won't fire. Theres no spark.

 

All is well with the WJ now. The new computer fixed the volt guage and over charging problem and the cam sensor fixed everything else. It runs like a top now. Thanks to all that helped.

 

Glad to hear you have everything sorted out, and she's running strong again.