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

P0CB0

DC/DC Converter Voltage Below Threshold

The DC/DC converter output voltage on the 12 V side falls below the operating threshold while operation is commanded, suggesting partial converter failure.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / numberC / B0

Possible causes

  • Converter partial failure high

Inspection / repair

  • Difficulty: shop only
  • DIY: shop recommended
  • Estimated cost: 800–4000 €
  • Estimated time: 3–10 h
  • Component: dc dc converter
  • Component: low voltage battery
  • 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