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

P2A3F

Excessive Time to Enter Alternative Fuel Control

On bi-fuel vehicles, the AFCM cannot transition into alternative fuel control mode within the calibrated time window. Tank pressure low, vaporizer cold, or fuel quality limits the change-over.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberA / 3F

Possible causes

  • Alt fuel tank pressure low high
  • Vaporizer not yet at operating temperature medium

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 100–800 €
  • Estimated time: 0.5–4 h
  • Component: afcm
  • Component: alt fuel tank
  • Component: alt fuel vaporizer
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

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