OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P0A0C

High Voltage System Interlock Circuit Low

The HV interlock signal is below threshold, indicating broken loop or short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / numberA / 0C

Possible causes

  • Interlock loop broken high
  • Connector pins corroded - high contact resistance low
  • Harness chafing through insulation low

Inspection / repair

  • Difficulty: shop only
  • DIY: shop recommended
  • Estimated cost: 200–1500 €
  • Estimated time: 1–5 h
  • Component: hv interlock loop
  • Component: hv service connector
  • MIL / check engine light
  • limp mode possible

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication