1999 Grand Cherokee pcm issues
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
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
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?
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.
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
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
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.
Trending Topics
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.
CF Veteran




Joined: Nov 2015
Posts: 2,856
Likes: 201
From: syracuse ny
Year: 1997
Model: Grand Cherokee (ZJ)
Engine: 4.0, new lifters valve job with new springs and exhaust valves, preload set with shims
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
Joined: Sep 2013
Posts: 518
Likes: 3
From: Santa Cruz Ca.
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.7
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
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
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.
Thread
Thread Starter
Forum
Replies
Last Post
Kevin Hubbell
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
9
Jun 11, 2016 06:11 AM
RonV88
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
Jun 9, 2016 08:56 PM
hondotexas
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
Feb 18, 2013 08:17 PM
qualm
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
2
Feb 28, 2011 06:01 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)



