Juicejam

2000, 2WD, 4.2L, Auto

Vehicle cannot shift out of neutral. Shift lever moves, cable is connected. Scanned and three codes come up:
P0603 Internal Control Module KAM Error
P0755 Shift Solenoid B Fault
P1400 DPFE Circuit Low Voltage

My harness had been touching against one of the smaller engine exhaust pipes and I had smelt burning from that area. The corrugated plastic sheathing of the harness was melted but the wires inside appeared intact. I had placed some electrical tape as a buffer in the area where the sheath had melted.

Is the fault in the solenoid an electrical power issue?

Any help would be really appreciated.

miked79928

I think since you identified the issue on the harness that is the best place to start. I would look at the solenoid last.

formerjeepguy

The P0603 troubles me. I think that indicate a keep alive memory problem. Look for and correct any issues in the wiring harness. Make sure there are no shorts or open wires.

A short or solenoid issue *could* have taken out the PCM. Poke a piece of paper clip into pin 55 on the PCM and look for constant battery voltage. I think it can go as low as about 8.5 volts before it sets the code. If the voltage is good then the PCM is probably bad. If the voltage is low or zero then trace the circuit and find the problem. It could even be a bad fuse.

Good luck.

Juicejam

Thanks very much. I will start with the fuses. Which fuse is for the PCM?

white89gt

I believe it is fuse number 2 in the box under the hood. It also runs the instrument cluster though, so you might have something else wonky.

Juicejam

Checked the fuse, it is ok. Inspected the harness in more detail. Found two separate wires with their insulation coating melted stuck together. I pulled them apart and found one exposed and thin. Could this have shorted out something? I guess that is where I continue my work.

white89gt

Yes... what size was the fuse? It is supposed to be a 5 amp. Did someone go bigger?

Juicejam

Ah, I think we are talking about two different fuses. I looked in the fusebox under the hood at the 30A fuse (F1.2 PCM power relay). I gather you are talking about the one under the passenger compartment inside the truck. Will have to check that one now.

By the way, the burnt wires are due to the harness touching against one of the exhaust tubes from the engine block. The insulation on the tube was worn off so the heat burnt through the plastic tubing of the harness and then unto the wires.

white89gt

Oh, you're right.... it's under the dash. My bad - sorry. Fuse number 2, under the dash.

Juicejam

Thanks, Whitey. Just checked and this fuse is also fine. Will have to direct focus to the wires now.