Coolant Pump Control Circuit Low
The P2602 code indicates that the Engine Control Module (ECM) has detected a low voltage condition in the control circuit of the coolant pump. This pump is responsible for circulating coolant through the engine and, in some vehicles, the turbocharger or heater core. A low voltage signal suggests a short to ground, open circuit, or faulty pump motor, which can lead to inadequate coolant flow, overheating, and potential engine damage.
01. Most Common Causes
- Faulty coolant pump motor
- Open or shorted wiring in the control circuit
- Poor electrical connection at the pump connector
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine overheating
- Reduced heater performance
- Coolant leaks near the pump
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Visually inspect the coolant pump connector and wiring for damage or corrosion.
Step 3: Test the pump control circuit voltage with a multimeter (should be near battery voltage when commanded on).
Step 4: Check the pump motor resistance; compare to specifications.
Step 5: If wiring and pump are okay, test the ECM output or replace the pump.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with a faulty coolant pump can cause engine overheating and severe damage. It is recommended to have the vehicle towed to a repair shop.
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.