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Camshaft Position Sensor (Method With Oscilloscope)

Disconnect the ground terminal from battery sensor. <Ref. to BATTERY , NOTE, Note.>
Prepare an oscilloscope.
Remove the engine control module (ECM). <Ref. to REMOVAL , Engine Control Module (ECM).>
Install the ST between the ECM and bulkhead harness and the engine harness. <Ref. to CAUTION , General Description.>
ST 18460AA030 CHECK BOARD
Connect the ground terminal to battery sensor. <Ref. to BATTERY , NOTE, Note.>

Connect the probe to ST.

Intake camshaft position sensor

Fig 1: Checking Waveforms And Voltage Of ECM - Intake Camshaft Position Sensor
Courtesy of SUBARU OF AMERICA, INC.
Exhaust camshaft position sensor

Fig 2: Checking Waveforms And Voltage Of ECM - Exhaust Camshaft Position Sensor

G11574616

Courtesy of SUBARU OF AMERICA, INC.

Camshaft position sensor		Terminal No.	Probe
Intake	RH	20	+
Intake	LH	21	+
Exhaust	RH	32	+
Exhaust	LH	33	+
RH and LH		34	-

Start the engine and let it idle.
Check the waveforms and voltage.
NOTE: For waveform and voltage, refer to "Engine Control Module (ECM) I/O Signal". <Ref. to Engine Control Module (ECM) I/O Signal .>
After inspection, install the related parts in the reverse order of removal.