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

P0664

Intake Manifold Tuning Valve Control Circuit Low Bank 2

Same as P0661 on bank 2. The intake manifold runner control (IMRC) flaps tune intake geometry for filling efficiency across the rpm range; stuck flaps cost part-load torque and can set lean codes.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number6 / 64

Possible causes

  • Control line shorted to ground high
  • Connector pins corroded - high contact resistance low
  • Harness chafing through insulation low

Symptoms

  • Check engine light on
  • Possible limp mode or no-start
  • Multiple follow-up faults across modules
  • Reset/relearn may be needed after repair

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 120–500 €
  • Estimated time: 0.6–2 h
  • Component: intake manifold tuning valve b2
  • 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