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

P2371

Fuel Volume Regulator B Control Circuit Performance

The ECU sees implausible feedback on the control loop for fuel volume regulator B - duty cycle does not match measured rail pressure response. The regulator either reacts too slowly, sticks, or has shifted from its calibration.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number3 / 71

Possible causes

  • Regulator stem sticking due to debris or wear high
  • High-pressure pump wear changes regulator response medium

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 200–1500 €
  • Estimated time: 1–4 h
  • Component: fuel volume regulator b
  • Component: high pressure pump b
  • Component: fuel rail
  • MIL / check engine light
  • emissions-relevant

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