P0A0DHigh Voltage System Interlock Circuit A High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- The voltage sensed on interlock loop A is higher than expected – most often a short to a voltage source, or the loop not being pulled down when the module expects it. GM checks both states: in the 2016 HPC2 table P0A0D sets when the sensed voltage exceeds 24 % of 5 V with the source switched off (5 of 8 samples) or 44 % with it switched on (4 of 6 samples), Type A with MIL after one trip. Hyundai's Sonata Hybrid 2011-2015 bulletins send P0A0D straight to the HEV safety plug, alongside high-voltage path and relay codes, with check engine light and no ready mode. Mercedes model line 243 stores P0A0D00 in the battery management as a short to positive. P0A0C is the low-side counterpart; both leave the HV system switched off.
- What you may notice
- No ready mode or ready light blinking
- Check engine and charging warning lights on
- Vehicle cannot be started
- Likely causes
- LikelyService/safety plug not fully inserted or with poor contact (Hyundai Sonata Hybrid)
- PossibleInterlock wire shorted to a 12 V or reference voltage
- PossibleDamaged interlock harness or connector after body or battery work
- RareFaulty interlock stage in the battery or hybrid control module
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.