Primary Speed Sensor: Inspection

2022 Subaru Impreza Base, 4D Sedan, Automatic CVT TransSECTION Inspection
WARNING: This page is about a different car, the 2022 Subaru Crosstrek. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check for oil leaks.
  2. Check the output waveform and output voltage of the primary speed sensor.
    1. Disconnect the ground terminal from battery sensor. Ref. to REPAIR CONTENTS>REPAIR CONTENTS>NOTE>BATTERY .
    2. Remove the clip from the air intake boot, and loosen the clamp.
      G11252776Courtesy of SUBARU OF AMERICA, INC.
    3. Remove the air intake boot, and place it aside so that it does not interfere with the work.
      CAUTION:

      Be careful not to pull out the PCV hose. 

      G11252777Courtesy of SUBARU OF AMERICA, INC.
    4. Disconnect the ground cord.
      G13603170Courtesy of SUBARU OF AMERICA, INC.
    5. Remove the pitching stopper. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580 CROSSTREK)>TRANSMISSION MOUNTING SYSTEM>REMOVAL>PITCHING STOPPER .
    6. Remove the transmission case cover (front).
      G13603171Courtesy of SUBARU OF AMERICA, INC.
    7. Move the lock lever in the arrow direction while pressing the lock button (A), and disconnect the connector.
      G13592051Courtesy of SUBARU OF AMERICA, INC.
    8. Set the ST between the TCM and transmission harness. Ref. to TRANSMISSION (DIAGNOSTICS) (CROSSTREK MODEL)>GENERAL DESCRIPTION>CAUTION .

      Special tool: 

      CHECK BOARD (18460AA040)

    9. Install the air intake boot. Ref. to INTAKE (INDUCTION) (H4DO (EXCEPT FOR HEV))>AIR INTAKE BOOT>INSTALLATION .
    10. Connect the ground terminal to battery sensor. Ref. to REPAIR CONTENTS>REPAIR CONTENTS>NOTE>BATTERY .
    11. Connect the probe of oscilloscope to ST.
      G13225684Courtesy of SUBARU OF AMERICA, INC.
      Terminal No. Probe
      14 +
      26 -
    12. Start the engine and warm up completely.
    13. Lift up the vehicle.
      CAUTION:
      • Lift up the vehicle until the tire bottom is 0.3 m (0.98 ft) or more above the ground. 
      • Make sure that safety is secured where the tiers rotate. 
    14. Turn OFF the pre-collision brake function.
    15. Turn the VDC function OFF.
    16. Release the parking brake.
    17. Shift the select lever to "D range".
    18. Release the brake pedal, and rotate the tires.
    19. Check the output waveforms and output voltage.
    NOTE:

    For the output waveform and output voltage, refer to "TRANSMISSION (DIAGNOSTICS)". Ref. to  TRANSMISSION (DIAGNOSTICS) (CROSSTREK MODEL)>TRANSMISSION CONTROL MODULE (TCM) I/O SIGNAL>WAVEFORM>SENSOR  . 

  3. After inspection, install the related parts in the reverse order of removal.
NOTE:
  • When connecting the connector to the TCM, move the lock lever and confirm that a clicking sound is heard. 
  • Insert the transmission case cover (front) between transmission case cover (rear) and transmission body. 
  • When inserting, be careful that the insulator inside transmission case cover is not turned over. 
G11255547Courtesy of SUBARU OF AMERICA, INC.

Tightening torque: 

7 N.m (0.7 kgf-m, 5.2 ft-lb)

G13603171Courtesy of SUBARU OF AMERICA, INC.

Tightening torque: 

32.3 N.m (3.3 kgf-m, 23.8 ft-lb)

G13603170Courtesy of SUBARU OF AMERICA, INC.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.