What it means
The control circuit of the HV battery precharge contactor A reports a control circuit/open condition. Precharge sequence cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Precharge contactor A is the controlled switch used in the DC-link precharge sequence. The control module monitors its circuit for continuity, and P0AE4 sets when that circuit appears open or cannot be commanded reliably. An open wire, failed coil, or pushed-back connector pin can stop precharge and prevent normal high-voltage operation.
Common causes
Most likely first.
- Open in coil control wire
- Open contactor coil
- 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
- Review freeze-frame and live data for the precharge-contactor A command and sequence status when the open condition was detected.
- With the vehicle safely powered down, inspect contactor A's connector for a pushed-back pin, poor seating, or corrosion.
- Trace the control wire to precharge contactor A and check for breaks, damaged insulation, or an open connection.
- Measure contactor A coil continuity and resistance against the manufacturer's specification.
- If the wiring and coil pass, verify the control signal and module response using the vehicle's service procedure.
Common fixes
- Seat the connector pin correctly and secure the connector.
- Repair an open in contactor A's control wire or connector.
- Replace precharge contactor A if its coil is open or outside specification.
- Repair the control module circuit if testing confirms it is not providing the expected command.
Can I keep driving?
Limit driving because the vehicle may have reduced power or may fail to enter Ready mode when precharge cannot be commanded. Arrange prompt hybrid-system diagnosis, particularly if charging is affected.
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.