What Does P0AE2 Mean?
The hybrid battery precharge contactor is stuck in the closed position and will not open when commanded by the battery ECU. This means the precharge resistor remains in the HV circuit even after the main contactors close, which wastes energy as heat through the resistor and can damage or overheat the precharge resistor. It also indicates the contactor contacts may be welded together from excessive arcing.
Safety Warning
A stuck-closed precharge contactor keeps the precharge resistor in the HV power path, which can overheat and potentially catch fire. Additionally, it means the battery cannot be fully isolated during shutdown or emergency disconnect, creating a serious safety hazard. The vehicle must be serviced immediately by HV-qualified personnel.
Common Causes
35%
Welded precharge contactor contacts from repeated high-current arcing
25%
Mechanically jammed contactor armature in the closed position
18%
Failed precharge resistor causing excessive current that welded the contacts
12%
Battery ECU continuously commanding the contactor closed due to software fault
10%
Contamination or debris preventing armature return spring from opening the contactor
Diagnostic Steps
1
With the vehicle off, monitor the precharge contactor status via the scan tool; if it shows closed with no command, the contactor is physically stuck.
2
Following HV safety procedures, de-energize the HV system completely before any physical inspection of the contactor.
3
Inspect the precharge contactor for signs of overheating, discoloration, or deformation of the housing that would indicate contact welding.
4
Measure resistance across the contactor's main terminals with the coil de-energized; near-zero resistance confirms welded contacts.
5
Inspect the precharge resistor for burn marks, cracking, or open circuit; a failed resistor causes excessive current through the contactor.
Estimated Repair Cost
$400 - $1,800
Parts + labor, varies by vehicle and location
The hybrid battery precharge contactor is stuck in the closed position and will not open when commanded by the battery ECU. This means the precharge resistor remains in the HV circuit even after the main contactors close, which wastes energy as heat through the resistor and can damage or overheat th...
The most common cause of P0AE2 (Hybrid Battery Precharge Contactor Circuit Stuck Closed) is: Welded precharge contactor contacts from repeated high-current arcing
Typical repair costs for P0AE2 range from $400 to $1,800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A stuck-closed precharge contactor keeps the precharge resistor in the HV power path, which can overheat and potentially catch fire. Additionally, it means the battery cannot be fully isolated during shutdown or emergency disconnect, creating a serious safety hazard. The vehicle must be serviced immediately by HV-qualified personnel.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0AE2 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Hybrid High-Voltage Battery Contactors
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
