P0A0D on Ford: How to Diagnose & Fix
High Voltage System Interlock Circuit High
1 Ford model · 1 documented issue · 1 critical · $600-$3,000 repair
P0A0D on Ford by model: symptoms, diagnosis and fix
On the battery-electric Focus, the high-voltage pack's main positive and negative contactors (relays) fail - either welding stuck closed or burning their contacts open. When a contactor faults, the on-board charger cannot close the HV circuit, so the car reports a charging fault, refuses to accept AC from either the 120V convenience cord or a 240V EVSE, and may throw HV isolation faults. Owners on the Focus Electric community have traced dead-charge conditions to burnt contactors in the upper pack, sometimes alongside coolant intrusion into the pack, and Ford also issued service information for HV packs that will not charge on the second-generation 120V charge cord.
Common Symptoms
- Vehicle will not charge on 120V or 240V
- Charge port light does not illuminate or flashes an error
- Stop Safely Now or high-voltage warning message
- Unlocking charge cord message on the display
- Loss of range or no propulsion
How to Fix
Diagnose with the HV pack DTCs before replacing the charge cord or the on-board charger - a stuck or open contactor sets specific battery energy control module codes. The repair is replacement of the affected contactor inside the HV battery pack, which requires a high-voltage-qualified technician (pack de-energizing, isolation testing, coolant loop handling). If the pack shows coolant intrusion, that leak must be repaired or the replacement contactor fails again. Also verify the EVSE and its charge-cord software level, since the factory second-generation 120V cord has its own no-charge service fix.
Sources for this issue (3)
P0A0D code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0A0D mean on a Ford?
P0A0D stands for "High Voltage System Interlock Circuit High." The high-voltage interlock circuit voltage is high (typically an open in the HVIL loop). An open interlock causes the HV system to disable for safety. On Ford it is documented across 1 model: Focus.
What are the most common causes of P0A0D?
The most common causes of P0A0D are: Open HV interlock loop (disconnected connector or service plug), Broken interlock wire, Corroded/damaged pins, Control module fault. The specific cause varies by vehicle.
How much does it cost to fix P0A0D on a Ford?
Published repair estimates on Ford range from $600 to $3,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0A0D on a different make?
View P0A0D across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.