When I turn the key over the gauge lights on, sentry key lights and check engine lights on. The Jeep will not turn over gauges don’t move, the battery and alternator connections are fine. I replaced the crank and cam sensors which the Jeep ran fine for a drive then the radiator cap blew which in turn made the problem I have now exist I checked all the connections even replaced the fuses.
Old fart with a wrench
When you say it won't turn over, do you mean it won't crank or it won't fire up? 4.0 or 4.7?
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It’s a 4.7 and it won’t fire up as in the starters working but it won’t start at all. The lights work headlights radio it has voltage. It’s like the pcm not plugged in but it is. At this point I have no idea what it could be. I would replace the skim and pcm from another Jeep but I have no idea honestly.Originally Posted by dave1123
When you say it won't turn over, do you mean it won't crank or it won't fire up? 4.0 or 4.7?
Old fart with a wrench
Get someone to check the crank sensor for putting out a signal. Without that signal, the PCM won't turn on the fuel pump, ignition, or injectors. You can also swap the fuel pump and ASD relays. If the ignition and injectors are hot, the engine will fire and run on residual fuel pressure for about 2 to 3 seconds, provided the PCM gets that crank sensor signal.
So I replaced the pcm still no gauge light and sentry lights on, even replaced the fuel pump got a new battery checked the connections. At this point I’m at a loss it’s like there’s no pcm at all
Newbie
have you check the PCM itself for proper operation? They mostly use a hall effect sensor with a magnet. Find the one you have check the wiring diagram. Provide 12 volts if it's a four wire. If its a two wire then you can use the continuity signal from the multi-meter.
Senior Member
Where did you get the PCM from? If you got it from one of those hack rebuilders in Florida, you may have made no progress.
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what do you mean check the wiring diagram? There’s three plugs that plug into the pcm itself. And I got the pcm from flagship one with a lifetime warranty, as of right now no spark and no fuel when key is turned over Originally Posted by xintersecty
have you check the PCM itself for proper operation? They mostly use a hall effect sensor with a magnet. Find the one you have check the wiring diagram. Provide 12 volts if it's a four wire. If its a two wire then you can use the continuity signal from the multi-meter.
I assume our newbie poster meant to say have you checked the crank sensor for operation. My friend, you are buying and installing parts without proper or for that matter any diagnosis. You will go broke pretty quickly and make things worse like that. I see no indication to do any of the things you have done, from what you describe.
What form of English translation might we use to decypher this sentence.". The lights work headlights radio it has voltage."
What form of English translation might we use to decypher this sentence.". The lights work headlights radio it has voltage."
Senior Member
97grand4.0 is correct. This is no way to go about solving your problem. What happened to your old PCM? You just may need it. : https://reviews.birdeye.com/flagship...49438559399200
Old fart with a wrench
It's most likely the crank sensor that costs about $50. I told you to check it's signal because without it the PCM won't turn on the ignition and injectors. Do the diagnosis or use the parts cannon, your choice.
