96 Intrepid shut down

96 Intrepid 3.5L engine 4LE trans 105000 miles

Trans overhauled about 8000 miles ago with new solenoid pack. Has new cam, crank sensors. Also has new coil pack and pcm.

Car runs normally when cold. Once it warms up it shuts down. Shows code 43 indicating a loss of coil voltage. Shut down last night after test drive. Found the Automatic shut down relay disengaged. Manually jumped it and car started and ran normally. Traced the actuation wire for the relay to the pcm. It shows.3 ohms from one end to the other and open to ground. Have Haynes books on it, but their schematics are wrong.

Any ideas? It does have an alarm, but it's tied to the start circuit only. What triggers the shutdown relay? If it's the pcm, what triggers it?

Thanks

Found oem schematic for the car. OEM says the car isn't wired for 3.5 engine. Block, VIN, my eyes all agree that it's a 3.5. All parts over the life of the car (we've owned it since new) have been 3.5L. Checked the schematic for a 3.3. Schematic looks to match. Haven't checked all circuits yet, but the ones that I'm interested in match.

Still would like to know what makes the pcm turn the auto shutdown relay on and off.
Thanks