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

P0318

Rough Road Sensor A Signal Circuit

A general electrical fault is reported on rough-road sensor A — used to gate misfire detection so that engine vibration from rough roads is not misclassified as misfire.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number3 / 18

Possible causes

  • Sensor failed high

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–500 €
  • Estimated time: 0.5–2 h
  • Component: rough road sensor
  • MIL / check engine light
  • emissions-relevant

Sources

References

sae:J2012

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