Primary Speed Sensor: Inspection

WARNING: This page is about a different car, the 2016 Subaru Outback and 2016 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.

Remove the bulkhead harness connector from TCM. < Ref. to REMOVAL , Transmission Control Module (TCM). >
Set the ST between the TCM and bulkhead harness.
ST 18460AA040 CHECK BOARD
Set the probe of oscilloscope to the check board connector.
Terminals:

No. 14 (+) - No. 42 (-)

Fig 1: Identifying Bulkhead Harness Connector Terminals
Courtesy of SUBARU OF AMERICA, INC.
Start and warm up the engine.
Check the waveform of primary speed sensor with engine idling.
NOTE: The waveform cycle changes as the speed changes.

Fig 2: Primary Speed Sensor Signal Waveform
Courtesy of SUBARU OF AMERICA, INC.