Diagnostic Procedure

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK OUTPUT OF ABS WHEEL SPEED SENSOR USING SUBARU SELECT MONITOR. Select "Current Data Display & Save" on the Subaru Select Monitor. Read the defective ABS wheel speed sensor output.	Does the speed indicated on the display change in response to the speedometer reading during acceleration/deceleration when the steering wheel is in the straight-ahead position?	Go to step 2 .	Go to step 7 .
2 CHECK POOR CONTACT OF CONNECTOR. Turn the ignition switch to OFF.	Is there poor contact of connectors between VDCCM&H/U and ABS wheel speed sensor?	Repair the connector.	Go to step 3 .
3 CHECK CAUSE OF SIGNAL NOISE. Make sure the radio wave devices and electronic components are installed correctly.	Are the radio wave devices and electronic components installed correctly?	Go to step 4 .	Install the radio wave devices and electronic components properly.
4 CHECK CAUSE OF SIGNAL NOISE. Check if the noise sources (such as an antenna) are installed near the sensor harness.	Are noise sources installed?	Install the noise sources apart from sensor harness.	Go to step 5 .
5 CHECK VDCCM&H/U. Connect all connectors. Clear the memory. < Refer to CLEAR MEMORY MODE . > Perform the Inspection Mode. < Refer to INSPECTION MODE . > Read the DTC.	Is the same DTC displayed?	Replace the VDCCM&H/U. < Refer to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) . >	Go to step 6 .
6 CHECK OTHER DTC DETECTION.	Is any other DTC displayed?	Perform the diagnosis according to DTC. < Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >	It results from a temporary noise interference.
7 CHECK INSTALLATION OF ABS WHEEL SPEED SENSOR.	Is the ABS wheel speed sensor installation bolt tightened to 7.5 N.m (0.76 kgf-m, 5.5 ft-lb)?	Go to step 8 .	Tighten the ABS wheel speed sensor installation bolts.
8 CHECK ABS WHEEL SPEED SENSOR SIGNAL. Install the ABS wheel speed sensor. Prepare an oscilloscope. Check the ABS wheel speed sensor. < Refer to CHECK ABS WHEEL SPEED SENSOR UNIT , INSPECTION, Front ABS Wheel Speed Sensor. >	Does the oscilloscope indicate the waveform pattern like shown in the figure when the tire is slowly turned? Does the oscilloscope indication repeat the waveform pattern like shown in the figure when the tire is slowly turned in equal speed for one rotation or more?	Go to step 10 .	Go to step 9 .
9 CHECK ABS WHEEL SPEED SENSOR OR MAGNETIC ENCODER.	Are there foreign matter, breakage or damage at the tip of ABS wheel speed sensor or magnetic encoder?	Remove dirt thoroughly. Also replace the ABS wheel speed sensor or magnetic encoder as a unit with hub unit bearing if it is broken or damaged.	Go to step 10 .
10 CHECK CAUSE OF SIGNAL NOISE. Make sure the radio wave devices and electronic components are installed correctly.	Are the radio wave devices and electronic components installed correctly?	Go to step 11 .	Install the radio wave devices and electronic components properly.
11 CHECK CAUSE OF SIGNAL NOISE. Check if the noise sources (such as an antenna) are installed near the sensor harness.	Are noise sources installed?	Install the noise sources apart from sensor harness.	Go to step 12 .
12 CHECK VDCCM&H/U. Connect all connectors. Clear the memory. < Refer to CLEAR MEMORY MODE . > Perform the Inspection Mode. < Refer to INSPECTION MODE . > Read the DTC.	Is the same DTC displayed?	Replace the VDCCM&H/U. < Refer to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) . >	Go to step 13 .
13 CHECK OTHER DTC DETECTION.	Is any other DTC displayed?	Perform the diagnosis according to DTC. < Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >	It results from a temporary noise interference. NOTE: Though the ABS warning light, and the VDC warning light & VDC indicator light remain lit at this point, this is normal. Drive the vehicle at 12 km/h (7 MPH) or more in order to turn off the ABS warning light, and the VDC warning light & VDC indicator light. Be sure to drive the vehicle and check that the warning light goes off.