Motor Electronics Coolant Pump Control Performance
The P0C73 code indicates that the Engine Control Module (ECM) has detected a performance issue with the motor electronics coolant pump. This pump is responsible for circulating coolant through the inverter, motor, and other high-voltage components in hybrid/electric vehicles. The ECM monitors pump speed and flow; if actual performance deviates from expected, this code sets. Common causes include a faulty pump, electrical issues, or low coolant.
01. Most Common Causes
- Faulty motor electronics coolant pump
- Low coolant level or air in system
- Wiring or connector issues (open/short)
- Failed pump relay or fuse
02. Symptoms You Will Notice
- Check Engine Light on
- Overheating of hybrid/electric drive components
- Reduced performance or limp mode
- Unusual noise from coolant pump
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Inspect coolant level and condition; top off if low.
Step 3: Visually check pump wiring and connectors for damage.
Step 4: Test pump operation using a scan tool to command it on.
Step 5: Measure pump resistance and voltage supply; replace if out of spec.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with P0C73 can cause overheating of high-voltage components, leading to costly damage. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Pump replacement parts range $100-$300, plus labor. Total can be $200-$500 depending on vehicle.