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

P2633

Fuel Pump B Control Circuit Low

Voltage on the second fuel pump control line is below the expected window. Usually a short to ground or a shorted motor winding.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number6 / 33

Possible causes

  • Control wire shorted to ground high
  • Internal short in pump motor medium
  • Connector pins corroded - high contact resistance low

Symptoms

  • Check engine light on
  • Hard start, no start, or stalling under load
  • Power loss especially at high load or rpm
  • Possible long cranking time

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 180–1000 €
  • Estimated time: 0.8–3.5 h
  • Component: fuel pump b
  • Component: wiring harness
  • 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