I noticed you haven't been contacted for a couple of days. Have you made any progress?
First, see if it will start in neutral. The neutral safety switch may be failing.
If there are no sounds made by the starter, we need to check for power to the yellow wire with a gray tracer on the starter motor. You will need a helper to do this. This wire only receives power when the key is in the start position. Have a helper turn the key to the start position while you check that wire for power. If there is power, chances are the starter motor itself has failed. If there isn't power, we may have a problem with the totally integrated power module (TIPM).
The TIPM design has been known to fail. They have too many tiny pins in the connectors that can corrode or break. We'll cross this road if we have to.
I attached the wiring schematic for the starter circuit, so you have a reference.
Let me know what you find or if you have other questions.
See pics below. Note: The schematic was only one page long. I had to cut it in half to make it readable for you. I did overlap the two so you can follow from one to the next.
Images (Click to enlarge)
Friday, September 23rd, 2022 AT 9:34 PM