Powertrain, generic · Hybrid propulsion

P0A0E High Voltage System Interlock Circuit A Intermittent

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Loose or spread interlock contacts in an HV or low-voltage connector
Harness section with a broken strand that opens under vibration
Moisture entering through a damaged connector seal
Electrical interference on the interlock line or a weak module input

Symptoms

  • 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

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time1–6 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv interlock circuit awiring harnessbms

Related codes

P0A0AP0A0BP0A0CP0A0DP0D19

References: law.cornell.edu, ti.com, patents.google.com, patents.google.com.