Coolant Pump Control Circuit High
The P261D code indicates that the Engine Control Module (ECM) has detected a voltage higher than expected in the control circuit of the electric coolant pump. This pump is responsible for circulating coolant after engine shutdown to prevent hot spots and turbocharger heat soak. A high voltage condition typically points to a short to power, a faulty pump motor, or an ECM issue. This can lead to inadequate cooling, especially during idle or after shutdown, potentially causing engine overheating and damage.
01. Most Common Causes
- Short to battery voltage in the coolant pump control circuit
- Faulty coolant pump motor (internal short)
- Damaged wiring or connector at the coolant pump
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine overheating, especially in stop-and-go traffic or after shutdown
- Reduced cooling system performance
- Possible coolant leaks from pump
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect the coolant pump wiring and connector for damage, corrosion, or shorts.
Step 3: Using a multimeter, check the control circuit voltage at the pump connector with the ignition on. Should be near battery voltage when commanded on, but not excessively high.
Step 4: Test the coolant pump by applying battery voltage directly; if it doesn't run or draws excessive current, replace the pump.
Step 5: If wiring and pump are okay, suspect ECM issue; perform ECM power and ground checks.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The coolant pump may not function properly, leading to overheating, especially after shutdown. This can cause engine damage. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor. The coolant pump itself is often $50-$150, plus diagnostic time and labor for replacement.