P0A0EHigh Voltage System Interlock Circuit A Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- The interlock loop A signal drops out or jumps for short moments and then recovers, so the module sees an unstable loop rather than a lasting open or short. Typical are connectors with loose or spread contacts, harness sections that move with the body or drivetrain, and moisture in seals. No manufacturer documents P0A0E publicly; the GM tables only list P0A0C and P0A0D for the same loop. Reference designs and patents on interlock monitoring describe the loop as a current or voltage path through each HV connector and point out that contact resistance and interference can cause brief false trips. CARB treats the HVIL as a safety-only system. For the driver this means sudden HV shutdowns or no-starts that come and go; static faults use P0A0A to P0A0D.
- What you may notice
- Hybrid/EV warning that appears and disappears
- Occasional loss of ready mode or sudden shutdown of electric drive
- Intermittent no-start, often after rough roads or rain
- Likely causes
- LikelyLoose or spread interlock contacts in an HV or low-voltage connector
- PossibleHarness section with a broken strand that opens under vibration
- PossibleMoisture entering through a damaged connector seal
- RareElectrical interference on the interlock line or a weak module input
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.