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 venting air from the cooling system to prevent air pockets and ensure proper coolant flow. A high voltage reading typically points to a short to power, a faulty valve, or an issue with the wiring or connector. This can lead to improper cooling system operation and potential engine overheating.
01. Most Common Causes
- Short to power in the control circuit wiring
- Faulty coolant degassing valve
- Damaged connector or corroded terminals
- ECM internal failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine overheating or temperature fluctuations
- Coolant loss or visible leaks
- Poor heater performance
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect the coolant degassing valve and its connector for damage, corrosion, or loose pins.
Step 3: Using a multimeter, check for voltage at the valve connector with key on. If voltage is above 5V or battery voltage when commanded off, suspect a short to power.
Step 4: Test the valve resistance; compare to manufacturer specs (typically 10-30 ohms). Replace if out of range.
Step 5: Check for continuity between the valve control circuit and power sources; repair any shorts found.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The code indicates a potential cooling system issue that could lead to overheating and engine damage. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the cause. A valve replacement is usually under $100, plus diagnostic time.