2022 Subaru Ascent BaseFACTORY OEM SERVICE PROCEDURE

Front Wheel Speed Sensor: Inspection

  1. Check for oil leaks.
  2. Check the output waveform and output voltage of the front wheel speed sensor.
    1. Disconnect the ground terminal from battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
    2. Disconnect the connector from TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>Transmission Control Module (TCM)>REMOVAL .
    3. Set the ST between TCM and connector. Ref. to TRANSMISSION (DIAGNOSTICS)>General Description>CAUTION .

      Special tool: 

      CHECK BOARD (18460AA040)

    4. Connect the ground terminal to battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
    5. Connect the probe of oscilloscope to ST.
      G13225684Courtesy of SUBARU OF AMERICA, INC.
      Terminal No. Probe
      12 +
      26 -
    6. Start the engine and warm up completely.
    7. 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.
    8. Turn OFF the pre-collision brake function.
    9. Turn the VDC function OFF.
    10. Release the parking brake.
    11. Shift the select lever to "D range".
    12. Release the foot brake pedal, and then depress the accelerator pedal until the vehicle speed increases to 20 km/h (12 MPH).
    13. Check the output waveforms and output voltage.
      NOTE: For the output waveform and output voltage, refer to "TRANSMISSION (DIAGNOSTICS)". Ref. to TRANSMISSION (DIAGNOSTICS)>Transmission Control Module (TCM) I/O Signal>SENSOR .
  3. After inspection, install the related parts in the reverse order of removal.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.