What does code P1646 mean?

Q: What does code P1646 mean?

Check DTC Memory Of All Wheel Drive ECU. P1646 on a Volkswagen means the engine control module (ECM) has been commanded to check the fault memory of the all-wheel-drive (AWD) control unit and has found a problem or an inability to communicate. The ECM is not reporting a fault in its own systems; it is flagging that the AWD ECU either has stored its own diagnostic trouble codes (DTCs) or cannot be reached over the vehicle's data bus.

DTC codes / Volkswagen codes / P1646

P1646 · VolkswagenCheck DTC Memory Of All Wheel Drive ECU

P1646 on a Volkswagen means the engine control module (ECM) has been commanded to check the fault memory of the all-wheel-drive (AWD) control unit and has found a problem or an inability to communicate. The ECM is not reporting a fault in its own systems; it is flagging that the AWD ECU either has stored its own diagnostic trouble codes (DTCs) or cannot be reached over the vehicle's data bus.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.