Drive Motor Inverter Voltage Too High
The P0C79 code indicates that the voltage in the drive motor inverter circuit has exceeded the maximum allowable 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 damage the inverter, motor, or battery system, and is often caused by a faulty inverter, voltage sensor malfunction, or issues with the battery pack.
1. Symptoms You Will Notice
- Check Engine Light or hybrid system warning light on
- Reduced power or limp mode
- Vehicle may not start or move
- Possible battery overcharge warning
2. Most Common Causes
- Faulty inverter assembly
- Defective voltage sensor
- Battery pack overvoltage condition
- Wiring or connector issues in the high-voltage circuit
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Inspect high-voltage wiring and connectors for damage or corrosion.
Step 3: Test the inverter voltage sensor and compare readings to specifications.
Step 4: Check battery pack voltage and state of health; perform a battery load test if necessary.
Step 5: If no issues found, replace the inverter assembly and clear codes.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. High voltage can cause sudden loss of power or damage to the hybrid system. Have the vehicle towed to a repair shop.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Inverter replacement can range from $1,000 to $3,000 or more, depending on the vehicle.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.