Nothing Is Displayed On The Screen Or Indicators Do Not Illuminate: Wiring Diagram

Auto A/C

Air Conditioning System. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: Auto A/C - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Manual A/C

Air Conditioning System. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 2: Manual A/C - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK FUSE. Turn the ignition switch to OFF. Remove fuse No. 4, 31, 7 and 12 from the fuse & relay box. Check the condition of fuse.	Is the fuse blown out?	Replace the fuse.	Go to step 2 .
2 CHECK CONNECTOR. Check the connectors (i166), (i165), (i88), (i97) and (i80) for poor contact.	Is there poor contact of connector?	Repair the connector.	Go to step 3 .
3 CHECK A/C CONTROL PANEL POWER CIRCUIT. Remove the A/C control panel. Disconnect the A/C control panel connector. Measure the voltage between A/C control panel connector terminal and chassis ground after turning the ignition switch to ON. Connector & terminal Auto A/C (i88) No. 5 (+) - Chassis ground (-): (i88) No. 6 (+) - Chassis ground (-): Manual A/C (i88) No. 1 (+) - Chassis ground (-): (i88) No. 7 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 4 .	Check for open or short circuit in the harness between A/C control panel and fuse.
4 CHECK A/C CONTROL PANEL GROUND CIRCUIT. Measure the resistance of harness between A/C control panel and chassis ground after turning the ignition switch to OFF. Connector & terminal Auto A/C (i88) No. 12 - Chassis ground: Manual A/C (i88) No. 11 - Chassis ground:	Is the resistance less than 10 Ω?	Go to step 5 .	Repair the harness for ground line.
5 CHECK A/C CM POWER SUPPLY CIRCUIT. Install the A/C control panel. Disconnect the A/C CM connector. Measure the voltage between A/C CM connector terminal and chassis ground after turning the ignition switch to ON. Connector & terminal (i80) No. 1 (+) - Chassis ground (-): (i80) No. 2 (+) - Chassis ground (-): (i80) No. 3 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 6 .	Check for open or short circuit in the harness between A/C CM and fuse.
6 CHECK A/C CM GROUND CIRCUIT. Measure the resistance of harness between A/C CM and chassis ground. Connector & terminal (i80) No. 6 - Chassis ground:	Is the resistance less than 5 Ω?	Go to step 7 .	Repair the harness for ground line.
7 CHECK COMMUNICATION CIRCUIT. Measure the resistance of harness between A/C control panel and air conditioner control module. Connector & terminal Auto A/C (i88) No. 10 - (i80) No. 18: (i88) No. 4 - (i80) No. 7: Manual A/C (i88) No. 6 - (i80) No. 18: (i88) No. 12 - (i80) No. 7:	Is there continuity?	Go to step 8 .	Repair the harness.
8 CHECK COMMUNICATION CIRCUIT HARNESS. Measure the resistance between communication circuit harness and chassis ground. Connector & terminal (i80) No. 18 - Chassis ground: (i80) No. 7 - Chassis ground:	Is there continuity?	Repair or replace the short circuit of the harness.	Go to step 9 .
9 CHECK HARNESS. Using a tester, check continuity between terminals. Connector & terminal (i80) No. 18 - No. 7:	Is there continuity?	Repair or replace the short circuit of the harness.	Go to step 10 .
10 CHECK A/C CONTROL PANEL. Turn the ignition switch to OFF. Replace the A/C control panel with a properly functioning part.	Does the A/C control panel operate normally?	Since the A/C control panel has an internal error, replace A/C control panel with a new one. Refer to REMOVAL .	Since the A/C CM has an internal error, replace A/C CM with a new one. Refer to REMOVAL .