What Does P0C73 Mean?
DTC P0C73 indicates that motor electronics coolant pump A is not performing as commanded by the control module. The pump may be running too slowly, failing to achieve the required flow rate, or not responding properly to control signals. This pump is critical for maintaining safe operating temperatures of the power electronics including the inverter, DC-DC converter, and motor controller.
Safety Warning
Inadequate cooling of motor electronics can lead to inverter or motor controller overheating, resulting in sudden power loss or component damage. The vehicle will typically derate power significantly to protect components, potentially leaving the driver with limited propulsion.
Common Causes
30%
Worn or failing coolant pump motor (brushes, bearings, impeller wear)
25%
Wiring or connector fault in the pump control circuit (high resistance, open, short)
20%
Coolant system restriction or air pocket reducing pump effectiveness
15%
Control module driver circuit failure for pump A
10%
Low coolant level in the motor electronics cooling loop
Diagnostic Steps
1
Verify the motor electronics coolant level is at the proper mark and there are no visible leaks in the cooling loop.
2
Command the pump on via scan tool bidirectional control and listen for proper operation; note any unusual noise or vibration.
3
Measure the voltage and current at the pump connector while commanding various speeds; compare to manufacturer specs.
4
Inspect the pump wiring harness and connector for corrosion, chafing, or loose pins that could cause control signal degradation.
5
Check for coolant system restrictions such as collapsed hoses, clogged heat exchangers, or trapped air pockets that could impede flow.
6
If electrical checks pass, replace coolant pump A.
Estimated Repair Cost
$300 - $1,500
Parts + labor, varies by vehicle and location
DTC P0C73 indicates that motor electronics coolant pump A is not performing as commanded by the control module. The pump may be running too slowly, failing to achieve the required flow rate, or not responding properly to control signals. This pump is critical for maintaining safe operating temperatu...
The most common cause of P0C73 (Motor Electronics Coolant Pump "A" Control Performance) is: Worn or failing coolant pump motor (brushes, bearings, impeller wear)
Typical repair costs for P0C73 range from $300 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Inadequate cooling of motor electronics can lead to inverter or motor controller overheating, resulting in sudden power loss or component damage. The vehicle will typically derate power significantly to protect components, potentially leaving the driver with limited propulsion.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0C73 to identify the root cause.
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Quick Info
Category
Powertrain
System
Motor Electronics Thermal Management
Difficulty
Type
Generic (SAE)
Recommended Tools
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