P0C78

Q: Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

Hybrid/EV Battery System Precharge Time Too Long

High severity

The HV battery system precharge time is longer than the calibrated window. Indicates high resistance, weak contactor, or aged components.

Common causes

Increased resistance in path
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $440-3300
Contactor coil weakening
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $440-3300
See all causes + fix costs
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P0C78 mean?

P0C78 means "Hybrid/EV Battery System Precharge Time Too Long". It is a generic OBD-II code that points to a fault in the hybrid / ev powertrain.

What are the most common causes of P0C78?

increased resistance in path; contactor coil weakening; pack cell imbalance approaching service threshold — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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