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

P25BE

Alternative Fuel Disable Control Circuit / Open

The controller cannot drive the alternative-fuel disable line that switches a bi-fuel vehicle (CNG, LPG, hydrogen) back to gasoline. An open detected on the control side blocks the safety shutoff for the gas system.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / BE

Possible causes

  • Broken wire or corroded connector on the disable control line high
  • Open coil in the alt-fuel disable relay medium
  • Output driver in the alt-fuel control module faulty low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–600 €
  • Estimated time: 0.8–2.5 h
  • Component: alt fuel control module
  • Component: alt fuel disable relay
  • 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