OK so the check engine light is on code is p0705 (trans range selector). I ohmed out the old connector at the pins and discovered it wasn't sending any thing for reverse. I decided to pull the switch and attempt to rebuild it. That didn't end well so now there's a new switch on it. I have reverse lights, it only starts in neutral and park and shifts through all gears just fine...... So now I'm lost. Is this a wiring issue back to the pcm? Any help would be great thanks.

 

See if you can clear the code using a scanner or code reader, or, by disconnecting the battery negative post connector for about 5 minutes. See if the CEL goes out.

 

D'Oh...
To fast on the reply....

 

Pull the pos. and neg cables off the battery and touch them together for a second or two. Clears those pesky codes.

 

Tried clearing the code touching the positive to ground. Worked for about 3 second then came back.

 

You may want to perform the TRS (NSS) voltage checks in post #26 in this thread. https://www.cherokeeforum.com/f2/p16...201769/index2/ using a digital voltmeter.

The TCM pinout is in post #24.

The TCM gets its power from fuse #10 in the JB.

 

Thanks I'll see what I get messing around with those today. Not sure if it has any bearing on the TCM issue but my passenger side rear turn, brake, and reverse lights are doing some crazy things like alternating, it blinking faster when I hit the brakes I was thinking that was just a short in the multifunction switch but could it be a symptom of an underlying common problem?

 

Take a look at the grounds and connectors behind the spare tire mount.

 

Didn't get around to checking the TCM pin out. The toilet flooded my house this morning. I finished welding panels back in where I had to grind off the mounting nuts for the rear shocks. Did mess with the lights. In reverse the rear passenger marker light is getting just a little bit of voltage. With lights on only the rear pass alternates with turn signal and marker and causes all dome lights to blink but only while using the right turn signal or 4 way. All grounds look brand new.

 

Unrelated to the code but the lights were a ground under the passenger side seat I never reconnected when I replaced the floor pans.
Does any know where the grounds for the trans circuits run? I'm thinking that's where the problem lies here too since I replaced almost half way up the fire wall and the trans tunnel when I did the floors.

 

The TCM is grounded at your coil mount bracket studs (G101). So is the battery (-) cable, PCM, and the Oxygen Sensor heaters.

It's a good idea to pull the wire ring terminals off these studs and scrub them clean with 400 grit sandpaper or 3M Scotch Brite Gray pads, and securely reattach. This has fixed a few problems in the past.

The solenoids in the trans are grounded through the trans body. The trans body is grounded through the bellhousing to the engine, then to the battery via those coil studs.

To assure the chasiss is being properly grounded to the battery, there's a small (AWG 8) cable running frrom the battery (-) post to the right inner fender. This ground point (G100) is essential for all chassis grounds. Like the coil stud wires, remove the bolt at G100 and clean the ring terminal and derust the fender so a good contact is made when reassembling it.

DO NOT use Dielectric grease on any ground points.

 

CCKen you rock, I actually found another one of your posts that covered all the grounds in the engine compartment. Unfortunately after cleaning all of them with sand paper and rust remover in addition to having to replace two o-rings that didn't want to come off (the two for the TCM near the coil) it is still sowing the check engine light. The first couple times it took about 10 seconds to come on but now it just stays on again.

 

OK so what I hope should be the final update on this issue as I was driving over to autozone to have the code read to verify it was still the same and not a new one the check engine light went out and it's still in the computer but I'm thinking it's just there as history since the lights not on. Yes the light comes on when you first turn the key so it's not blown. Really hope it's fixed. Again thanks for your help CCKen

 

Glad to help.