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Not getting power to fuel injector from PCM

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Old 08-29-2018 | 12:05 AM
  #16  
Patrick Sargent's Avatar
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Default Same issue

I'm having the same issue I'm not getting a pulse from injector #4 at the PCM but I have constant power on the other wire that's on the injector did anyone figure this out I went over all the wires and the plug everything is good just dead at the computer and it's only injector 4 everything else is fine..also mine is a 2000 Cherokee Sport 4.0

Last edited by Patrick Sargent; 08-29-2018 at 12:07 AM. Reason: Left somethang out
Old 08-29-2018 | 08:21 AM
  #17  
awg's Avatar
awg
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Year: 96
Model: Cherokee (XJ)
Engine: 4.0
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Originally Posted by Patrick Sargent
I'm having the same issue I'm not getting a pulse from injector #4 at the PCM but I have constant power on the other wire that's on the injector did anyone figure this out I went over all the wires and the plug everything is good just dead at the computer and it's only injector 4 everything else is fine..also mine is a 2000 Cherokee Sport 4.0
The answers from previous posts indicate a bad splice, wire, or connector is preventing the injectors path to PCM Earth being the most likely cause

these faults can be very hard to track down. I used home made needle backprobes with jumper leads to prove out and bypass some electrical faults on my XJ

worse than 50yr old Lucas wiring

Old 08-29-2018 | 04:44 PM
  #18  
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From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
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He needs to hotwire that injector to see if the coil is open. Or switch it around to see if the miss follows the injector. Either way, it must be proved the injector itself is not at fault.
Old 08-28-2020 | 11:25 PM
  #19  
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From: Jeddah, Saudi Arabia
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0L
Default #2&4 injectors doesn't work

Hi all:
I have exactly the same problem in my 2000 XJ (code P0204), I undo the injectors wire loom that runs beside the valve cover and I saw the wires in a very bad shape, all stuck together, you con not remove one wire, it will strip off the insulation because of the heat.
Anyhow I have a 12V on the DG/OR power wire, I have a continuity on the ground LB/BR wire that goes to the white connector ( C2). I figured it is the PCM that is not sending a ground signal to the injector.
I bought a full used engine wiring including fuse box and PCM, so I am waiting it to come, then I will replace the old wiring and see how it will go.
My issue started with #4 injector but later #2 injector quit.

Last edited by Hamid; 08-28-2020 at 11:29 PM.
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Udahmann (01-16-2021)
Old 01-16-2021 | 03:05 PM
  #20  
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Where is point S115? I am trying to replace a damaged #6 injector circuit.
Circuit to PCM is good.
Old 10-13-2021 | 06:07 PM
  #21  
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Default Injector ground continuity

Originally Posted by Hamid
Hi all:
I have exactly the same problem in my 2000 XJ (code P0204), I undo the injectors wire loom that runs beside the valve cover and I saw the wires in a very bad shape, all stuck together, you con not remove one wire, it will strip off the insulation because of the heat.
Anyhow I have a 12V on the DG/OR power wire, I have a continuity on the ground LB/BR wire that goes to the white connector ( C2). I figured it is the PCM that is not sending a ground signal to the injector.
I bought a full used engine wiring including fuse box and PCM, so I am waiting it to come, then I will replace the old wiring and see how it will go.
My issue started with #4 injector but later #2 injector quit.
When you say you have continuity on your ground wire, I'm assuming you mean between the injector and the PCM, not between the injector and chassis ground (which should read infinite if the PCM driver's good). I think......

Last edited by KelKel; 10-13-2021 at 06:22 PM. Reason: Should add to compare resistance of PCM to Injectpr ground to other injector ground wires in order to rule out ground-wire to chassis short
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doublechaz (10-14-2021)
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