P1648-vw

Pull up the passenger-side carpet/sill panel, open the TCM plastic box, and look for water, condensation, or green corrosion on the pins.

I can help identify the most likely culprit and direct you to the specific module to check. VW P1648 Code: Troubleshooting and Solutions | JustAnswer p1648-vw

This is a communication error between ECUs, not necessarily a failed sensor. 1. Common Causes Pull up the passenger-side carpet/sill panel, open the

Repairing broken CAN bus wires.

Using a wiring diagram, check continuity of the high and low CAN Bus wires (usually orange/black and orange/brown) between the TCM and ECM. 4. Typical Fixes Pull up the passenger-side carpet/sill panel