P0C78
Hybrid/EV Battery System Precharge Time Too Long
P0C78 is an OBD-II diagnostic trouble code meaning: Hybrid/EV Battery System Precharge Time Too Long. Common causes: faulty precharge relay, damaged pre-charge resistor. Estimated repair cost: $56–278.
Symptoms
- Hybrid system does not activate
- Check Engine light comes on
- A hybrid system fault message appears
- Reduced vehicle performance
- The car goes into emergency mode
Causes
- Faulty precharge relay
- Damaged pre-charge resistor
- Problems with high voltage battery
- Malfunction of the hybrid system control module
- Open or short circuit in the precharge circuit
How to Fix
- Carry out diagnostics of the high-voltage system
- Check relay and precharge resistor
- Test the integrity of the precharge circuit
- Check the condition of the high-voltage battery
- Update or replace the control module if necessary
- Repair only from an authorized dealer
Related codes
Error P0C78 by Vehicle Brand
FAQ
What does the P0C78 code mean?
P0C78 is an OBD-II diagnostic trouble code that indicates: Hybrid/EV Battery System Precharge Time Too Long
What causes a P0C78 error code?
The most common causes of P0C78 include: Faulty precharge relay; Damaged pre-charge resistor; Problems with high voltage battery; Malfunction of the hybrid system control module.
How do I fix a P0C78 diagnostic trouble code?
To fix P0C78: Carry out diagnostics of the high-voltage system. Check relay and precharge resistor. Test the integrity of the precharge circuit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0C78?
Do not drive — repair immediately
How much does it cost to fix P0C78?
The estimated repair cost for P0C78 is $56–278. Actual cost depends on your vehicle, location, and labor rates.
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