What does code P1391 mean?

Q: What does code P1391 mean?

CMP Sensor Bank 2 Short To Ground. P1391 on a Volkswagen means the engine control module (ECM) has detected a short to ground on the signal circuit of the bank 2 camshaft position (CMP) sensor. The ECM monitors the sensor's signal voltage and flags this code when that circuit is pulled below the expected threshold, indicating a wiring or sensor fault rather than a mechanical timing problem.

DTC codes / Volkswagen codes / P1391

P1391 · VolkswagenCMP Sensor Bank 2 Short To Ground

P1391 on a Volkswagen means the engine control module (ECM) has detected a short to ground on the signal circuit of the bank 2 camshaft position (CMP) sensor. The ECM monitors the sensor's signal voltage and flags this code when that circuit is pulled below the expected threshold, indicating a wiring or sensor fault rather than a mechanical timing problem.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

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