Drive Motor Inverter Voltage Too High
The P0C79 code indicates that the voltage detected by the drive motor inverter control module is higher than the specified threshold. This typically occurs in hybrid or electric vehicles where the inverter converts DC battery power to AC for the drive motor. High voltage can be caused by a faulty inverter, voltage sensor issues, or problems with the high-voltage battery system. If left unaddressed, it may lead to inverter damage or reduced performance.
01. Most Common Causes
- Faulty inverter assembly
- Defective voltage sensor
- High-voltage battery overcharging
- Wiring or connector issues in the inverter circuit
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced motor power or performance
- Vehicle may enter limp mode
- Possible warning messages on dashboard
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm the code and check for related codes.
Step 2: Inspect the inverter and high-voltage wiring for damage or loose connections.
Step 3: Test the inverter voltage sensor using a multimeter and compare to specifications.
Step 4: Check the high-voltage battery state of charge and charging system for overvoltage.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. High voltage can damage the inverter or other components, and the vehicle may lose power unexpectedly.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on whether the inverter needs replacement or just sensor/connector repair.