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

P2A84

Alternative Fuel Pump B Compression Stroke Valve Control Circuit Range/Performance

The control circuit of the compression stroke valve in alternative fuel pump B reports a control circuit range/performance condition. Pump compression stroke cannot be commanded as expected.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberA / 84

Possible causes

  • Valve responds slower than expected high
  • High-resistance contact in connector medium
  • Sensor element aged beyond calibration window 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: hard
  • DIY: shop recommended
  • Estimated cost: 300–1500 €
  • Estimated time: 2–6 h
  • Component: alt fuel pump b compression stroke valve
  • Component: wiring harness
  • Component: afcm
  • MIL / check engine light
  • emissions-relevant
  • 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