PCM replacement?

J

jcbarr

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Aug 16, 2022
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Kyle, TX
I've heard PCMs are hard to find these days. I've got a 1998 4.0L. Codes showing #5 cylinder problem (P0205) even after I replaced injector, switched it to see if it's defective, and replaced connector. The injector is not clicking. So I'm thinking it's the PCM.

One mechanic told me those are too difficult to find today. True? Any recommended brands?

Thanks
 
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@jcbarr We can repair that issue and save you some money on replacing yours.

Call me tomorrow at 866-888-7710 whenever you get a chance.

Thanks,

Mark
 
I would not even consider talking to anybody but Mark and his crew- These are just not another product in their line - it is what they do. They are specialists, and they know how to do business.
 
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You need to check to make sure the PCM controlled ground isn't shorted to ground before you throw a PCM at it (VERY COMMON). Otherwise you're just chucking parts and shooting in the dark. There are a few ways to skin this cat. But I believe this is the quickest way.

With an INCANDECENT test light connected to Battery Negative: With Key On/Engine Off, Unplug #5 injector. Gently touch Pin 1 (Orange/Dark Green Tracer). Test light should light.

With Key On/Engine Off, Switch Test light to Battery Positive. Gently touch Pin 2 (Pink/Black Tracer). Test light SHOULD NOT light.

If the test light illuminates by touching Pin 2 connected to battery positive with the key on/engine off, it can mean a couple of things. Most likely is that the control wire (injector ground) running back to the PCM is shorted to a permanent ground which means you're constantly dumping fuel into the cylinder because it's firing all the time. Most of the time the short is located behind the valve cover where the fuel injector wiring runs back to the PCM.

OR, it could mean that the driver for the #5 injector inside the PCM is shorted to ground (less likely but possible.)


If the test light doesn't illuminate by touching pin 2 while connected to battery positive, then you need to check PCM control by installing a Noid light with the engine running. It should flash. If the noid light doesn't flash, you need to run continuity from Pin 2 to PCM to verify the control wire isn't broken. If wire integrity is good, THEN you need a PCM.
 
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Hey everyone i have an 03 Tj sport auto and she is fighting me . Not sure what the issue is right yet . I put her in the ditch a month ago and now she is having some kind of electrical issue of some sort. Dash cluster drop off and it's triggered the skim Imobiliser system she did it to me first at gas pumps a week after the ditch . Start 2 seconds then shut down .happened 4 times in a row the 5th time she kept running but the key with circle and line threw was still lit up . Dash cluster would work for a few seconds then drop off . I've peeled into the wire harnesses that run next to battery along fender to look for breaks looks really clean behind dash cluster wires look great . Now I am looking to see how hard it is to get pcm replacement or rebuild I'm not sure what is best option . @Wranglerfix I'm wondering if I may call you at some point see what the deal on the pcm is I love her and she's my only wheels . 03 Tj sport 4.0 190k km 🇨🇦 I'm in Canada as well northern Ontario thanks in advance
 
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TJ Jimmy said:
Hey everyone i have an 03 Tj sport auto and she is fighting me . Not sure what the issue is right yet . I put her in the ditch a month ago and now she is having some kind of electrical issue of some sort. Dash cluster drop off and it's triggered the skim Imobiliser system she did it to me first at gas pumps a week after the ditch . Start 2 seconds then shut down .happened 4 times in a row the 5th time she kept running but the key with circle and line threw was still lit up . Dash cluster would work for a few seconds then drop off . I've peeled into the wire harnesses that run next to battery along fender to look for breaks looks really clean behind dash cluster wires look great . Now I am looking to see how hard it is to get pcm replacement or rebuild I'm not sure what is best option . Wranglerfix I'm wondering if I may call you at some point see what the deal on the pcm is I love her and she's my only wheels . 03 Tj sport 4.0 190k km 🇨🇦 I'm in Canada as well northern Ontario thanks in advance
Click to expand...

You need to tag Mark like this @Wranglerfix , but I’m not sure he’s on here too much. I’d go to his website and try to sort it out that way.

https://wranglerfix.com/product/jeep-wrangler-tj-replacement-pcms/
 
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