Motor Electronics Coolant Pump Control Performance
The P0C73 code indicates that the Motor Electronics Coolant Pump (MECP) is not performing within expected parameters. This pump circulates coolant through the inverter and motor electronics in hybrid/electric vehicles. The control module detects a discrepancy between commanded and actual pump speed or flow, often due to electrical faults, mechanical binding, or air in the system.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Overheating of motor electronics or inverter
- Reduced hybrid/EV performance or limp mode
- Coolant leaks near pump area
2. Most Common Causes
- Faulty Motor Electronics Coolant Pump
- Open or shorted wiring/connectors to pump
- Low coolant level or air in cooling system
- Failed pump control module or relay
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Inspect coolant level and condition; bleed air if necessary.
Step 3: Visually check pump connector and wiring for damage or corrosion.
Step 4: Test pump operation by commanding it on via scan tool; listen for operation and measure voltage/signal.
Step 5: If pump does not run, check power and ground at pump connector; if present, replace pump.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with P0C73 can lead to overheating of the motor electronics, potentially causing costly 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 $50 to $150 for diagnosis and minor repairs like a connector fix, but pump replacement can be $200-$500 including parts and labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.