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

P0A0D

High Voltage System Interlock Circuit High

The HV interlock signal voltage is above threshold, indicating short to battery or unexpected continuity loss.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / numberA / 0D

Possible causes

  • Short to battery on interlock high
  • Connector pins corroded - high contact resistance low
  • Supply wire pinched against B+ source 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

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