What it means
The control module monitors the control circuit for hybrid/EV battery pack coolant pump B. It sets this code when the circuit is open or its electrical continuity is interrupted.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery coolant pump B circulates coolant through the high-voltage battery thermal-management system. The control module monitors pump B's control circuit and sets P0E1A when electrical continuity is interrupted, such as by an open wire, an open motor, or a terminal that is not making contact.
Common causes
Most likely first.
- Open in pump control wire
- Open pump motor
- Pin pushed back out of connector body
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
- Read freeze-frame and hybrid-system live data for battery temperature, pump B command, and any recorded pump-speed or coolant-flow feedback when the fault occurred.
- With the vehicle powered down as specified by the manufacturer, inspect pump B's wiring and connector for damage, looseness, corrosion, or a pushed-back terminal.
- Check the pump B control circuit for continuity using the manufacturer's wiring diagram and procedure.
- Test pump B's motor circuit for an open condition according to the manufacturer's specification.
- If the wiring and motor pass, verify the module's command and pump B response using the manufacturer's diagnostic procedure.
Common fixes
- Seat or repair a loose pump B connector or pushed-back terminal.
- Repair an open or damaged pump B control wire.
- Clean or replace damaged pump B connector terminals.
- Replace pump B if its motor circuit tests open.
Can I keep driving?
A failed pump can reduce battery cooling or heating, which may lead to charging limits, reduced power, or further battery temperature warnings. Avoid strenuous driving or charging if the hybrid system reports overheating or severe power limits, and arrange prompt diagnosis.
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.