P2678
Coolant Degassing Valve Control Circuit / Open
This code indicates coolant degassing valve control circuit / open. It relates to the auxiliary emission controls and may affect performance, emissions, or drivability depending on the exact failure.
Coolant Degassing Valve Control Circuit / Open
Common causes
- medium
Sensor failure
O2, NOx, pressure, or temperature sensors can drift or fail.
Typical part cost: $100-400
- medium
Exhaust leak or restriction
Leaks before sensors or a restricted exhaust can set emissions codes.
Typical part cost: $100-400
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P2678 mean?
P2678 means "Coolant Degassing Valve Control Circuit / Open". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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