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Home >> Subaru >> 2012 >> Impreza WRX STi Limited >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Fuel Injection System (WRX-STI) >> Camshaft Position Sensor >> Inspection >> Camshaft Position Sensor (Method With Oscilloscope)

Camshaft Position Sensor (Method With Oscilloscope)

  1. Prepare an oscilloscope.
  2. Remove the lower inner trim of passenger's side. < Refer to REMOVAL , Lower Inner Trim. >
  3. Turn over the floor mat of passenger's seat.
  4. Remove the protect cover.
    Fig 1: Locating Protect Cover Mounting Screws
    G07704447Courtesy of SUBARU OF AMERICA, INC.
  5. Remove the nuts and bolts which hold the ECM to the bracket.
    Fig 2: Locating ECM Bracket Mounting Nuts And Bolts
    G07704448Courtesy of SUBARU OF AMERICA, INC.
  6. Connect the probe to ECM connector.
    • Intake camshaft position sensor
      Fig 3: Connecting Probe To ECM Connector (Intake Camshaft Position Sensor)
      G07704449Courtesy of SUBARU OF AMERICA, INC.
    • Exhaust camshaft position sensor
      Fig 4: Connecting Probe To ECM Connector (Exhaust Camshaft Position Sensor)
      G07704450Courtesy of SUBARU OF AMERICA, INC.
    CONNECTOR TERMINALS REFERENCE CHART

    Camshaft position sensor Terminal No. Probe
    Intake RH 24 +
    LH 16 +
    Exhaust RH 23 +
    LH 29 +
    RH and LH 30 -
  7. Start the engine and let it idle.
  8. Check the pattern is the same as the waveform and voltage shown below.
    Fig 5: Camshaft Waveform Pattern
    G07704451Courtesy of SUBARU OF AMERICA, INC.
  9. After inspection, install the related parts in the reverse order of removal.

    Tightening torque: 

    7.5 N-m (0.8 kgf-m, 5.5 ft-lb)