P2678

Coolant Degassing Valve Control Circuit/Open

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$17–56 (est.)

Symptoms

Engine overheating
Unstable engine operation
Increased fuel consumption
Check Engine Light Is On
Poor interior heating

Causes

Open or short circuit in control circuit
Degassing valve malfunction
Problems with the engine control unit
Corrosion of contacts or connectors
Wiring harness damage

How to Fix

Check the integrity of the valve control circuit
Check the resistance of the degassing valve
Inspect connectors and contacts for corrosion
Replace degassing valve if necessary
Check the operation of the system after repair

Related codes

P2677 P2679 P2680