What does code P066F mean?

Q: What does code P066F mean?

Cylinder 3 Glow Plug Control Circuit High. P066F indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for cylinder 3's glow plug, which is used in diesel engines to warm the combustion chamber for reliable cold starts. The PCM monitors the circuit and sets this code when the voltage exceeds the expected range, typically indicating an open circuit, a short to voltage, or a faulty glow plug control module.

DTC codes / P06xx · Computer and output circuits / P066F

P066FCylinder 3 Glow Plug Control Circuit High

P066F indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for cylinder 3's glow plug, which is used in diesel engines to warm the combustion chamber for reliable cold starts. The PCM monitors the circuit and sets this code when the voltage exceeds the expected range, typically indicating an open circuit, a short to voltage, or a faulty glow plug control module.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaComputer and output circuits

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