P1021 – VANOS Solenoid B Performance (BMW)

Description

P1021 BMW indicates VANOS solenoid B is not performing within expected parameters.

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Symptoms

  • Rough idle
  • Hesitation
  • Reduced power

Causes

  • Solenoid wear
  • Oil contamination
  • Wiring fault

Diagnosis

  • Test solenoid
  • Check oil condition
  • Inspect wiring

Repair

  • Replace solenoid
  • Change oil
  • Repair wiring