PCM Self test error code

[cmc3]

2017 XLT ~150k miles
I'm having a intermittent problem at first start when I have not used the suv in a few days. When I first start I get multiple module (ABS, PSCM, PAM, RCM) failures and multiple dash warnings. Switch it off ... try again ... everything seems to be working fine. Doesn't happen unless the car has been sitting a few days. Today I went out with FORSCAN for the initial start. The car started, but the modules listed above had faulted. I let the car run a few minutes then switched it off and restarted. This time all the modules can up. So I started running self tests.
NO ERRORS: ABS,PSCM,PAM,RCM,PHMC,HVAC

The PCM self test resulted in P1780:00 Transmission control switch out of range...repeat test same result
The car seems to run and shift correctly. Where is this switch?

Next day update:
Switch is inside the center console, next to shifter......however the problem seems to have gone away. The self tests run with no errors now.

Module problem on first start is also gone.

 

[Yupster Dog]

I'm having a intermittent problem at first start when I have not used the suv in a few days.

To make sure you are not running in circles you need to make sure the vehicle is getting proper power.
Have battery checked and load tested.
Take off and clean battery post and clamps.
Check all battery cables and connections. (voltage drop test)

Check all ground connections
When multiple systems show error like that, look for a lifted/intermittent ground somewhere.

 

[cmc3]

New battery, but the intermittent ground is a good pointer. I'll get out my wiring book and look for a common connection.