P2680 - Coolant Degassing Valve Control Circuit High
The P2680 code indicates that the Engine Control Module (ECM) has detected a high voltage condition in the control circuit of the coolant degassing valve. This valve is responsible for releasing air from the cooling system to prevent air pockets that can cause overheating. A high voltage reading typically points to a short to power, a faulty valve, or an issue with the wiring or connector.
1. Most Common Causes
- Faulty coolant degassing valve
- Short to power in the control circuit
- Damaged wiring or connector
- Failed ECM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine overheating
- Coolant loss or leaks
- Poor heater performance
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the coolant degassing valve and its wiring for damage or corrosion.
Step 3: Test the valve's resistance with a multimeter (specs vary by vehicle).
Step 4: Check for voltage at the valve connector with key on; if voltage is present when it shouldn't be, repair short to power.
Step 5: If wiring and valve are okay, test the ECM output or replace the valve.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The valve controls coolant flow and air release; a malfunction can lead to overheating and engine damage.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and repair, including parts and labor. The valve itself costs $20-$60.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.