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

P240D

Alternative Fuel Low Pressure System Leak

A leak detected in the low-pressure side of an alternative fuel system (LPG, CNG between regulator and rail, or H2 between vapouriser and rail). Risk of escape into the engine bay.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / 0D

Possible causes

  • Hose or fitting leak high

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–800 €
  • Estimated time: 0.8–3 h
  • Component: alternative fuel low pressure line
  • 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