DTC P0890 At Self-Shut Relay Diagnosis (Low): Wiring Diagram

Fig 1: Self-Shut Relay - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK HARNESS.  Disconnect the TCM and self shut relay connectors. Measure the resistance between TCM connector and self shut relay connector. Connector & terminal  (B55) No. 20 - (B494) No. 1:  (B55) No. 2 - (B494) No. 3:  (B55) No. 11 - (B494) No. 3:  (B55) No. 22 - (B494) No. 3:	Is the resistance less than 1 Ω?	Go to step 2  .	Repair the open circuit of harness.
2 CHECK HARNESS.  Measure the resistance between TCM connector and chassis ground. Connector & terminal  (B55) No. 20 - Chassis ground:  (B55) No. 2 - Chassis ground:  (B55) No. 11 - Chassis ground:  (B55) No. 22 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 3  .	Repair the short circuit of harness.
3 CHECK RELAY POWER SUPPLY.  Measure the voltage between self shut relay connector and chassis ground. Connector & terminal  (B494) No. 2 (+) - Chassis ground (-):  (B494) No. 4 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 4  .	Repair the open or short circuit of harness.
4 CHECK SELF SHUT RELAY.  Measure the resistance between self shut relay terminals. Connector & terminal  (B494) No. 1 - (B494) No. 2:	Is the resistance 110 - 140 Ω?	Go to step 5  .	Replace the self shut relay.
5 CHECK SELF SHUT RELAY.  Measure the resistance between self shut relay terminals. Connector & terminal  (B494) No. 3 - (B494) No. 4:	Is the resistance 1 MΩ or more?	Go to step 6  .	Replace the self shut relay.
6 CHECK INPUT SIGNAL FOR TCM.  Connect the connectors of TCM and self shut relay. Read the data of "Battery voltage" using Subaru Select Monitor.	Is the "Battery voltage" 10 V or more?	Current condition is normal. Check for poor contact of the connector or harness, and repair the fault location.	Go to step 7  .
7 CHECK FOR POOR CONTACT.	Is there poor contact of the self shut relay circuit?	Repair the poor contact.	Check the TCM.