What it means
The HV battery pack coolant pump A reports a control circuit high condition. Battery thermal management may be impaired.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery-pack coolant pump A circulates coolant through the battery thermal-management system, while its control circuit operates or regulates the pump. P0C49 sets when the module detects a high electrical condition on that control circuit, which can result from a short to voltage or a pump or driver fault.
Common causes
Most likely first.
- Short to voltage in the pump control circuit
- Faulty coolant pump or driver
- Poor connector connection
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Save freeze-frame data and review related codes, then compare pump A's requested and reported status in live data or through a supported scan-tool command.
- With the vehicle powered down as specified by the manufacturer, inspect pump A's connector and control wiring for loose terminals, corrosion, or damaged insulation.
- Check the control circuit for a short to voltage using the manufacturer's wiring diagram and test procedure.
- Inspect the pump and driver connections for poor contact or wiring damage that could put unintended voltage on the control circuit.
- If no wiring fault is found, test pump A and its driver against the manufacturer's specification to determine which is causing the high reading.
Common fixes
- Reconnect and secure a loose pump A connector.
- Repair control wiring shorted to voltage.
- Repair or replace damaged connector terminals or wiring.
- Replace pump A or its driver if testing confirms the component is faulty.
Can I keep driving?
Avoid high loads and charging while this fault is active because pump A's control may not manage battery cooling correctly. Stop if the vehicle limits power or shows a battery-temperature warning, and arrange diagnosis promptly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.