What does code P2678 mean?

Q: What does code P2678 mean?

Coolant Degassing Valve Control Circuit / Open. P2678 indicates that the powertrain control module (PCM) has detected an open circuit or a general circuit fault in the control wiring for the coolant degassing valve, which is used to manage coolant flow and vent gases in the cooling system. The PCM monitors the valve's control circuit and sets this code when the expected voltage or current is outside the normal range, typically indicating a break in the wiring or a failed valve.

DTC codes / P26xx · Computer and output circuits / P2678

P2678Coolant Degassing Valve Control Circuit / Open

P2678 indicates that the powertrain control module (PCM) has detected an open circuit or a general circuit fault in the control wiring for the coolant degassing valve, which is used to manage coolant flow and vent gases in the cooling system. The PCM monitors the valve's control circuit and sets this code when the expected voltage or current is outside the normal range, typically indicating a break in the wiring or a failed valve.

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.