What does code P1786 mean?

Q: What does code P1786 mean?

Reversing Light Circuit Open. P1786 on Volkswagen vehicles indicates that the transmission control module (TCM) has detected an open circuit in the reversing light circuit, which is typically wired through the transmission range sensor or a dedicated switch on the gearbox. The TCM expects a specific voltage or continuity on the reversing light output when reverse gear is selected, and it sets this code when that signal is missing or out of range.

DTC codes / Volkswagen codes / P1786

P1786 · VolkswagenReversing Light Circuit Open

P1786 on Volkswagen vehicles indicates that the transmission control module (TCM) has detected an open circuit in the reversing light circuit, which is typically wired through the transmission range sensor or a dedicated switch on the gearbox. The TCM expects a specific voltage or continuity on the reversing light output when reverse gear is selected, and it sets this code when that signal is missing or out of range.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

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