Could use some help. My brother has a 96 5.0 Auto. It would stall and not start until it seemingly had cooled down. It got to the point where it wouldnt start at all.

We replaced both the coil and the Ignition module. Still nothing. We then rebuilt the distributor. Now it starts, but it is throwing a P1351 Ignition Diagnostic Monitor Cicuit Input Malfunction Code.

Im at a loss on what to check on this. I searched previous posts on IDM and saw something about a possible open resistor.

Can anyone direct me to where this resistor might be, or if you have any ideas for me to check, that would be great.

Thanks

 

The fault is one of the following:

ICM
PCM
Wiring harness (short ot open)

Start by verifying continuity between the ICM and PCM. Then, check the IDM line for short to ground or short to battery power.

If no faults are found, check for the IDM signal while cranking. If none is found, then either the ICM is not generating the signal or the PCM input circuitry is faulty and is killing the signal.

Looking at a previous poster's experience with an aftermarket ICM (he also got a P1351 after ICM replacement), I'd suspect the ICM as the reason for the P1351.

Sorry, don't have a 96 service CD so I can't check specifics for your truck.

Steve