DTC C1542: Clutch On Fault

DTC detecting condition:

Abnormal clutch signal

Trouble symptom:

Hill start assist does not operate.

Wiring diagram:

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

Engine electrical system Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM

CAN communication system Ref. to WIRING SYSTEM>CAN COMMUNICATION SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

NOTE:

Depending on the user clutch operation patterns, the hill start assist warning light may illuminate for a while, and then go off.

Illumination condition:

While the vehicle speed is 10 km/h (6 MPH) or above, and the clutch switch signal ON (depressed) condition continues five minutes or more, if the vehicle speed lowers to 10 km/h (6 MPH) or below, the module judges as abnormal (clutch switch stuck ON), and then turns on the warning light.

Turning off condition:

If the clutch switch signal OFF (foot released) condition continues for 2 seconds, the module turns off the warning light.

The hill start assist function does not operate, while the warning light illuminates.

CHECK LAN SYSTEM .
Check the LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE

Is the check result OK?

Yes : Go to 2.

No : Perform the diagnosis for LAN system.
CHECK CLUTCH SIGNAL USING SUBARU SELECT MONITOR .
Using the Subaru Select Monitor, read data of [Clutch Switch] in the [Data Monitor] of [Brake Control]. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DATA MONITOR

Is [OFF] displayed when the clutch pedal is not depressed, and is [ON] displayed when depressed?

Yes : Go to 5.

No : Go to 3.
CHECK CLUTCH SIGNAL OF ECM USING SUBARU SELECT MONITOR .
1. Using the Subaru Select Monitor, read data of [Clutch Switch] in the [Data Monitor] of [Engine]. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DATA MONITOR
Is [OFF] displayed when the clutch pedal is not depressed, and is [ON] displayed when depressed?

Yes : Go to 5.

No : Go to 4.
CHECK HARNESS BETWEEN ECM AND CLUTCH SWITCH (CHECK FOR OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the clutch switch.
4. Measure the resistance of harness between ECM and clutch switch connector.
  Connector & terminal
  
  (B61) No. 24 - (B115) No. 2:
Is the resistance less than 1 Ω?

Yes : Repair the power supply circuit of clutch switch. Or replace the clutch switch. Ref. to CLUTCH SYSTEM>CLUTCH SWITCH

No : Repair the harness between ECM and clutch switch connector.
CHECK VDC Control Module & H/U .
1. Connect all connectors.
2. Using the Subaru Select Monitor, perform the clear memory of [Brake Control]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY
3. Execute the inspection mode. Ref. to BRAKE CONTROL (DIAGNOSTICS)>INSPECTION MODE
4. Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)
Is the same DTC displayed?

Yes : Replace the VDC Control Module & H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDC CONTROL MODULE & H/U)

No : Go to 6.
CHECK DETECTION OF OTHER DTCS FOR VDC .
Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)

Is any other DTC displayed?

Yes : Perform the diagnosis according to the DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST

No : Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.