Coolant Pump Control Circuit Low
The P261C code indicates that the Engine Control Module (ECM) has detected a low voltage condition in the control circuit of the electric coolant pump. This pump is responsible for circulating coolant through the engine and heater core, especially after shutdown to prevent hot spots. A low circuit voltage suggests a short to ground, open circuit, or faulty pump motor, which can lead to inadequate cooling, overheating, and potential engine damage.
1. Most Common Causes
- Faulty electric coolant pump motor
- Open or shorted wiring in the pump control circuit
- Corroded or loose connector at the coolant pump
- Failed ECM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine overheating, especially after shutdown
- Reduced heater performance
- Coolant leaks near the pump
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the coolant pump connector and wiring for damage, corrosion, or loose connections.
Step 3: Using a multimeter, check the control circuit voltage at the pump connector with the engine running. Expected: battery voltage (12V+). Low voltage indicates a short or open.
Step 4: Test the pump motor by applying direct battery voltage. If pump does not run, replace the pump.
Step 5: If wiring and pump are good, check for ECM issues (rare) and perform a continuity test from the pump connector to the ECM.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The coolant pump may not operate properly, leading to engine overheating and potential damage. Have the vehicle inspected and repaired as soon as possible.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. The coolant pump itself costs $50-$150, and labor adds $100-$250 depending on vehicle accessibility.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.