What it means
The HV battery precharge contactor is stuck in the closed position. Risk of damage to precharge resistor from sustained current.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The precharge contactor closes temporarily to charge the high-voltage DC link through a resistor before the main contactors close. P0AE2 sets when the control module detects that this contactor remains closed when it should release. A welded contact, stuck driver, or obstructed mechanism can keep current flowing through the precharge path and risk overheating its resistor.
Common causes
Most likely first.
- Contacts welded closed
- Driver stuck on
- Carbon or debris buildup preventing free movement
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 command and reported state, including whether it remains closed after the sequence should end.
- With the vehicle safely powered down, inspect the precharge-contactor connector and harness for damage or a control wire that could keep the driver energized.
- Following the manufacturer's service procedure, verify whether the control module continues commanding the contactor after the expected precharge period.
- Have the precharge contactor and its driver circuit tested for welded contacts, sticking operation, or a shorted driver.
- Inspect the precharge resistor and related components for evidence of overheating before returning the vehicle to service.
Common fixes
- Repair a shorted control wire or connector fault that keeps the contactor energized.
- Replace a precharge contactor with welded or sticking contacts.
- Repair the driver circuit if testing confirms it is stuck on.
- Replace heat-damaged precharge-path components after correcting the cause.
Can I keep driving?
Do not continue normal driving or repeated start attempts; a precharge contactor that stays closed can overheat the resistor and leave the vehicle unable to operate. Have the hybrid system assessed 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.