Grounding problem from PCM I think

[James2004 2.4]

4or5 codes later and still stuck 2004 TJ Wrangler 2.4 first code cam shaft sensor ran for a day then crank shaft sensor ain't ran since. Figured out fuel pump wasn't working then figured out no ground got fuel pump working now no injectors. I have bought every kinda tester got a pretty good scan tool how do I figure out if it's wiring harness or PCM cause I've just about rewired the hole thing and now I'm showing tps problem's and still the injectors ain't firing someone please for my sanity help me

 

[hear]

you can back probe near the PCM to determine if it's getting a good ground, and if it's distributing a good ground. Most of the sensors use the ground supplied by the PCM. Wiring diagrams can be found in the Resources section on this site. But to your specific question, wiring problems & computer problems have a tendency to look pretty similar.

It would be nice to know if you have power to the coil & injectors initially, and if it is the ASD that is shutting things down for you.

Clocksprings have been known to cause screwy issues related to sensors as well.

 

[James2004 2.4]

I have fire everywhere except at the injectors and now it's throwing the code for the TPS so I'm kinda lost and is this asd the little box hooked to the side of the head on the left with a ground strap hooked to the fire wall

 

[macleanflood]

You could send your PCM to @Wranglerfix for testing.

I'd open up your factory service manual, section 8w, and look up the grounds and go through each one and clean it up and ohm it out to it's nearest splice.

-Mac

 

[hear]

I have fire everywhere except at the injectors and now it's throwing the code for the TPS so I'm kinda lost and is this asd the little box hooked to the side of the head on the left with a ground strap hooked to the fire wall

ASD is the automatic shutdown relay, its in the power distribution center (aka fuse box) under the hood. I'm not sure what the "little box hooked to the side of the head" is. Pics would help.

 

[James2004 2.4]

Ok I got fire to the injectors I'm getting a p0123 code witch is TPS but this box on the side of the head is hooked to the grounding stud and it has a connector hooked to it with a green and black stripe wire going to it so I know that's a ground coming from the PCM. So I unplugged it and ran a straight ground wire to the plug and it popped my injector fuse under the hood just as soon as I got the switch so does that mean I gotta a short in the harness from the PCM to the injectors or TPS or somewhere else or maybe just rip out every wire and start over

 

[macleanflood]

I'd look up where that lands on the PCM connectors and ohm check it before you do anything else.

-Mac

 

[hear]

or maybe just rip out every wire and start over

never a terrible idea, unfortunately.

 

[macleanflood]

never a terrible idea, unfortunately.

Unless you cause more problems than you started with. Oh the problems with 20 year old cheap wiring harnesses.

-Mac

 

[James2004 2.4]

Thank you everyone I have figured it out and it was in the wires going to the reverse light switch don't know how that happens but my woman has been having this Intermenton problem for about 5 years before I came along and she says she just wiggled them wires down there and a mechanic showed her that and it was the crank shaft sensor wires she sometimes it will start and sometimes it sits for a week maybe a month and she goes outside and it starts I guess stranger things have happened anyway I might have got a little lost on this job but these little 2.4 Dodge neon motors I call them I do know a little bit about them and if you take a little bit of time with them they will take a beatin

 

[hear]

Unless you cause more problems than you started with.

-Mac

It's a rare TJ harness where that is even possible.

 

[macleanflood]

Ive found my early 97 harness is pretty good. Probably before the bean counters figured they'd make more money outsourcing the harness.

Mine survived getting pulled and swapped over to another tub. And while I pulled some of it apart... transmission and engine harness...most of it I didn't touch.

-Mac