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

P2D9E

High Voltage System Voltage Low

The high-voltage system voltage is below the expected window. HV battery output drops, isolation event, or loaded too heavily.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberD / 9E

Possible causes

  • HV battery cells aged high
  • BMS regulation outside calibration medium

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 500–5000 €
  • Estimated time: 3–16 h
  • Component: hv battery
  • Component: bms
  • Component: hv bus
  • 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