DTC P0842 Secondary Oil Pressure Sensor Circuit (Low): Wiring Diagram

CVT Control System. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: CVT Control System - Wiring Diagram (Secondary Oil Pressure Sensor)

G08318812

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK INPUT SIGNAL FOR TCM. Start the engine. Warm up until the ATF temperature reaches to 40 - 70°C (104 - 158°F). Shift the select lever to "P" range. Stabilize the engine speed at idle. Read the data of «Actual secondary pressure» using Subaru Select Monitor.	Is the «Actual secondary pressure» 0.5 - 1.5 MPa?	Check for poor contact of connector.	Go to step 2 .
2 CHECK HARNESS. Turn the ignition switch to OFF. Disconnect the TCM and transmission connectors. Measure the resistance between TCM connector and transmission connectors. Connector & terminal (B54) No. 2 - (B12) No. 12: (B54) No. 15 - (B12) No. 10: (B54) No. 17 - (B12) No. 11:	Is the resistance less than 1 Ω?	Go to step 3 .	Repair the open circuit of harness.
3 CHECK HARNESS. Measure the resistance between TCM connector and chassis ground. Connector & terminal (B54) No. 2 - Chassis ground: (B54) No. 17 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 4 .	Repair the short circuit of harness.
4 CHECK TRANSMISSION HARNESS. Disconnect the secondary pressure sensor connector. Measure the resistance between transmission connector and secondary pressure sensor connector. Connector & terminal (T3) No. 10 - (AT6) No. 3: (T3) No. 11 - (AT6) No. 2: (T3) No. 12 - (AT6) No. 1:	Is the resistance less than 1 Ω?	Go to step 5 .	Repair the open circuit of harness.
5 CHECK TRANSMISSION HARNESS. Measure the resistance between transmission connector and chassis ground. Connector & terminal (T3) No. 11 - Chassis ground: (T3) No. 12 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 6 .	Repair the short circuit of harness.
6 CHECK SENSOR POWER SUPPLY. Connect the connectors of TCM and transmission. Turn the ignition switch to ON. Measure the voltage between secondary pressure sensor connector terminals. Connector & terminal (AT6) No. 1 (+) - (AT6) No. 3 (-):	Is the voltage 4.5 V or more?	Replace the secondary pressure sensor. Refer to SECONDARY PRESSURE SENSOR .	Check for poor contact of the connector, and repair the defective part.