DTC C1971 Clutch Sensor

DTC detecting condition:

A fault is detected if electrical malfunction is detected for clutch stroke sensor.

Trouble symptom:

Parking brake system does not operate.

Wiring diagram:

Vehicle dynamics control system <Ref. to VEHICLE DYNAMICS CONTROL SYSTEM .>

Fig 1: Clutch Stroke Sensor - Circuit Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK OUTPUT OF CLUTCH STROKE SENSOR USING SUBARU SELECT MONITOR. Using the Subaru Select Monitor, select "Data monitor". <Ref. to READ CURRENT DATA , OPERATION, Subaru Select Monitor.> Read the «Clutch stroke sensor» displayed on the screen.	When the clutch pedal is operated, does the value of «Clutch stroke sensor» change in accordance with the clutch pedal?	Go to step 7 .	Go to step 2 .
2 CHECK HARNESS. Turn the ignition switch to OFF. Disconnect the connector from clutch stroke sensor. Turn the ignition switch to ON. Measure the voltage between clutch stroke sensor connector terminals. Connector & terminal (B501) No. 3 (+) - (B501) No. 5 (-):	Is the voltage 4.5 V or more?	Go to step 3 .	Repair the power supply circuit of clutch stroke sensor.
3 CHECK HARNESS (CHECK FOR OPEN CIRCUIT). Turn the ignition switch to OFF. Disconnect the connector from the VDCCM & H/U. Measure the resistance of harness between clutch stroke sensor and VDCCM & H/U connector. Connector & terminal (B501) No. 3 - (B310) No. 11: (B501) No. 4 - (B310) No. 10: (B501) No. 5 - (B310) No. 15:	Is the resistance less than 1 Ω?	Go to step 4 .	Repair the harness and connector between clutch stroke sensor and VDCCM & H/U connector.
4 CHECK HARNESS (CHECK FOR GROUND SHORT CIRCUIT). Measure the resistance of harness between clutch stroke sensor and chassis ground. Connector & terminal (B501) No. 3 - Chassis ground: (B501) No. 4 - Chassis ground: (B501) No. 5 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 5 .	Repair the ground short of harness between clutch stroke sensor and VDCCM & H/U connector.
5 CHECK HARNESS (CHECK FOR SHORT CIRCUIT TO POWER SUPPLY). Turn the ignition switch to ON. Measure the voltage between clutch stroke sensor and chassis ground. Connector & terminal (B501) No. 3 (+) - Chassis ground (-): (B501) No. 4 (+) - Chassis ground (-): (B501) No. 5 (+) - Chassis ground (-):	Is the voltage less than 1 V?	Go to step 6 .	Repair short to power supply of harness between clutch stroke sensor and VDCCM & H/U connector.
6 CHECK CLUTCH STROKE SENSOR OUTPUT. Connect all connectors. Turn the ignition switch to ON. Using an oscilloscope, check clutch stroke sensor output. Connector & terminal (B501) No. 4 (+) - Chassis ground (-):	Is there any output?(Does a cyclic rectangular wave appear?)	Go to step 7 .	Replace the clutch stroke sensor.
7 CHECK POOR CONTACT OF CONNECTORS.	Is there poor contact of connector between VDCCM & H/U and clutch stroke sensor?	Repair the connector.	Go to step 8 .
8 CHECK VDCCM & H/U. Connect all connectors. Perform the Clear Memory Mode. <Ref. to CLEAR MEMORY MODE .> Read the DTC. <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>	Is the same DTC displayed?	Replace the VDCCM & H/U. <Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .>	Go to step 9 .
9 CHECK DETECTION OF OTHER DTCS FOR VDC. <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>	Is any other DTC displayed?	Perform the diagnosis according to DTC. <Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .>	Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.