intermittently will not start?

Hi,

It could be a few things. First, when it won't start, see if it does in neutral. If there is no change, the next thing I would recommend is checking the starter relay. It may be failing.

If there is a different relay having the same part number in the fuse box, switch them. If there isn't, here is a link that explains how to test it:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If that is good, we need to check the relay circuit to see if there is power to it as well as a ground path via the PCM. This vehicle has a totally integrated power distribution module (TIPM). They are known to have connector issues, so leave the key alone for now. Chances are that isn't the issue and yes, it needs to be programmed.

I attached the wiring schematic for the starter circuit below, so you have a reference.

Let me know what you find.

Take care,

joe

See pic below.

i replied earlier but didn't see it listed. The starter relay is on the firewall near the TIPM, i swapped it with the relay next to it and there is no change. As there is no voltage on the solenoid input, sometimes i wonder if there is a problem with the ignition switch actuator itself. with the key in the start/run position could i put 12v on the solenoid input on the starter itself to engage the starter? i did clean up the grounds on the firewall, some of them had deteriorated from so many being jammed into one eyelet/connector and will attach an image at a later date.

Hi,

I need you to check for power at the trigger wire on the starter itself. According to the schematic, it should be a brown wire. It should have battery voltage with the key in the start position. Have a helper turn the key while you check.

Often, the TIPM connectors fail. They will show 12v until a load is placed on them. If you check at the starter motor, we'll know if the voltage drops.

Let me know.

Joe