P0C77

Symptoms

• The check engine or hybrid system light comes on
• Reduced performance of the hybrid system
• The car may go into emergency mode
• Possible problems with charging the high-voltage battery
• Clicking or unusual noises from the high voltage compartment

Causes

• Pre-charge relay malfunction
• Problems with the precharge resistor
• Short circuit in high voltage circuit
• Malfunction of the hybrid system control unit
• Damage to the high voltage system wiring harness

How to Fix

1. Check the precharge relay for faults
2. Check the resistance and integrity of the precharge resistor
3. Diagnose high-voltage circuits for short circuits
4. Check the condition of the high voltage system wiring harness
5. Scan the hybrid system control module for additional errors
6. Repair only from an authorized dealer

Related codes

Error P0C77 by Vehicle Brand