Strange BMS and Sync related issues

[SVTRondogg]

Since I cannot see - exactly where they are tapping for power
I can assume they are Tapping
1. Direct Power
2. Switched Power
3. BOO (Brake on/off) signal wire from the BCM to the Shift Interlock
4. And a relay (in the pic) is the source for the security device control of that BOO signal

There is a bad connection - in that section of wiring or the relay itself is bad and what I THINK is happening is that the relay is hanging up - (sticking)
The security module (sees) constant power on the circuit from the relay as if the brake is applied and when powered down (Truck off) it still thinks the truck is running and does not (write to memory) last state - Valet Mode

Now for the APIM issue

Same thing except this is a Can Bus data transmission - the bus is staying awake as it thinks you are pressing the brake pedal - Brake (on) message along the HS3 Bus, the APIM is on that bus.

When you have the truck running and you press the brake pedal
1. Normal - you should hear a click in the center console and if you place your hand on the shifter, you can feel the interlock (clicking)

2. When the security device is (Armed) it prevents the (Relay-In Pic) from letting power through to the Shift Interlock (in Item #1) until you enter the code - i think it takes away the coil ground

3. When in (Valet) it either bypasses that relay or it provides the ground to the relay coil.

I would unbundle the wiring and inspect it for security and pull and reseat all connectors and possibly replace that coil as I have a suspicion that the issue is in that relay.

If you can identify where they are tapped (power and ground) we can do wire checks if needed.

From the pics it looks like they are tapping into
C2280D - It will be a Blue/Orange wire - this is the BOO signal to the shift interlock

and

C2280F - for power and grounds - hard to tell

The wiring will run from this location - to the security device

As I said - I cannot see exactly where they tapped - but the most logical failure point is the relay

I did some more digging today. It has taken a bit my schedule is always too tight to play in the garage anymore.

One symptom you noted earlier is the screen will stay on and frozen after key off and the door is open. Usually 3-5 minutes is my best estimate.

Today I unbundled the module and tried to separate all the interconnects between the module and the tapped wires.

I was able to unplug two of them, one was a light blue wire and one was green.

The remaining 3 were power, ground, and a 3rd signal wire I may have to go back in to identify. These 3 I cut since I was unable to remove the connect terminals and didn't want to pull too hard on the wire taps on the factory wire (I hate those things).

End result is the keypad is powered off, which is good. The bad is the shifter interlock stays engaged. As the work around for now I pulled the vinyl shifter trim up and have to manual press forward the plastic tab to shift out of park.

Let me know if any of these pictures is helpful.

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