@Weebs - You have a textbook
5-Volt Reference Circuit short-to-ground.
All those seemingly unrelated codes (P1628, P0340, P2228, P051C, P2127) share the exact same 5-volt power line (Circuit #2) from the PCM. If
one wire in that bundle chafes and touches bare metal, the entire 5V circuit drops to 0V, instantly killing the engine.
Heat softens the wire loom and engine mounts. A left turn shifts the engine's weight, pressing that bare wire against a metal ground. Straightening out pulls the wire away, turning "Active" codes into "Stored" codes.
They taped the wire 10 months ago but didn't reroute the harness away from the rub point. It just rubbed through the tape again.
Tell the dealer to stop test driving. Force an "Active" code in the service bay with a
"Hot Wiggle Test":
- Hook up the scanner to monitor live data for "Sensor Reference Voltage 2".
- With a heat-soaked engine running, aggressively wiggle, push, and yank the wiring harness near the old repair.
- If that fails, power-brake it (put in Drive, hold the brake firmly, and hit the gas while turning the wheel left) to torque the engine and simulate the physical shift of a turn.
The voltage will instantly drop to 0V, the truck will stall, and they'll have the active code they need. Tell them to fix the wire AND reroute the harness so it stops rubbing!
