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

P0340

Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)

The camshaft position (CMP) sensor signal is missing or implausible. The ECU uses CMP together with CKP to identify cylinder phase for sequential injection and coil-on-plug ignition; without CMP the engine may run on group injection or fail to start.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number3 / 40

Possible causes

  • Sensor failed high
  • Timing chain stretched, throwing off sensor timing medium
  • Wiring fault low

Symptoms

  • Check engine light on
  • Power loss especially in mid-rpm range
  • Possible rough idle or stalling
  • Increased fuel consumption

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–600 €
  • Estimated time: 0.5–4 h
  • Component: camshaft position sensor
  • Component: timing chain
  • Component: timing belt
  • 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