What does code P1618 mean?

Q: What does code P1618 mean?

Glow Plug Heater Relay Circuit Short To B+. P1618 on Volkswagen vehicles means the glow plug control module has detected a short to battery positive voltage in the glow plug heater relay circuit. The computer monitors the relay control wire and sees voltage present when the relay should be off, indicating a wiring fault or failed relay.

DTC codes / Volkswagen codes / P1618

P1618 · VolkswagenGlow Plug Heater Relay Circuit Short To B+

P1618 on Volkswagen vehicles means the glow plug control module has detected a short to battery positive voltage in the glow plug heater relay circuit. The computer monitors the relay control wire and sees voltage present when the relay should be off, indicating a wiring fault or failed relay.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

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.