P0AE6

What it means

P0AE6 is a generic code meaning the control circuit for hybrid or EV battery precharge contactor A is reading low. The precharge contactor lets current flow through a resistor to charge the high-voltage system's capacitors gently before the main contactors close. The control unit sets the code when the voltage or current on the contactor's drive circuit does not match what it commanded, which points to a short to ground, an open circuit or a fault in the driver.

Symptoms

• Hybrid or EV system warning light on the dashboard
• Vehicle will not go into READY mode or will not start
• Reduced power or the car running in limp-home mode
• Engine-only running on a hybrid, with no electric assist
• Charging not starting on a plug-in or electric vehicle
• Other high-voltage battery or contactor codes stored alongside

Possible causes

• Damaged wiring or poor connector contact in the precharge contactor control circuit, such as a short to ground or high resistancelikely
• Faulty precharge contactor or relay coil with an internal shortlikely
• Fault in the battery management or control unit driver circuit for the contactorpossible
• Corrosion or water ingress in the high-voltage battery pack connector or harnesspossible
• Low 12 V supply or poor earth to the battery control unit upsetting circuit readingspossible
• Outdated control unit software where the manufacturer has issued a known fix for this faultrare

How to diagnose

1. Read all stored codes and freeze frame data, noting whether other high-voltage or contactor codes are present and under what conditions this one was set
2. Check the 12 V battery condition and charging voltage, and inspect the main earth connections, as low supply can cause false circuit faults
3. Visually inspect the contactor control wiring and connectors for chafing, corrosion, water ingress and loose pins, following the model's service information
4. Check for any manufacturer service bulletins or software updates relevant to this vehicle and code
5. Make sure the high-voltage system is isolated and proven dead by a suitably trained person before any work near orange cables or the battery pack
6. Measure the contactor control circuit for continuity, short to ground and coil resistance against the manufacturer's specification, as the access point depends on the model
7. Use live data in a scan tool to command or monitor contactor operation if the model supports it, and compare the commanded and actual states
8. Clear the code and road test, then recheck to confirm whether it returns

How to fix

• Repair or replace damaged wiring and clean or replace faulty connectors in the contactor control circuit
• Replace the precharge contactor or relay if its coil resistance or operation is out of specification
• Repair or replace the battery control unit or its driver if the circuit and contactor test good
• Dry out, clean and reseal affected high-voltage battery connectors, replacing any that are corroded
• Fix the 12 V battery or earth fault if low supply is found, then retest
• Update the control unit software only where the manufacturer lists it as a fix for this fault

Can I keep driving?

Nearby codes

• P0AE5GenericHybrid/EV Battery Precharge Contactor A Control Circuit Range/Performance
• P0AE7GenericHybrid/EV Battery Precharge Contactor A Control Circuit High