P0C4B

Hybrid/EV Battery Pack Coolant Pump A Supply Voltage Circuit/Open

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–278 (est.)

Symptoms

Check Engine light comes on
Hybrid system power reduction
Battery overheating
Noise or lack of operation of the cooling pump
The vehicle goes into emergency mode

Causes

Open or short circuit in the pump power supply circuit
Faulty pump relay or fuse
Problems with the wiring harness or connectors
Failure of the cooling pump itself
Malfunction of the hybrid system control module

How to Fix

Check the coolant pump fuse and relay
Inspect the wiring harness and connectors for damage
Check the voltage at the pump terminals
Test or replace the cooling pump
Check the operation of the hybrid system control module

Related codes

P0C4A P0C4C P0C4D