DTC B1603 Evaporator Sensor Short: Wiring Diagram

Air Conditioning System. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: Evaporator Sensor - Wiring Diagram

G08348794

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK CONNECTOR. Check the condition of connector connection. Read the DTC using Subaru Select Monitor.	Is B1603 displayed?	Go to step 2 .	Check the connection of the evaporator sensor circuit.
2 CHECK EVAPORATOR SENSOR. Disconnect the evaporator sensor. Read the DTC of the A/C ECM using the Subaru Select Monitor.	Is B1604 displayed?	Replace the evaporator sensor. Refer to REMOVAL .	Go to step 3 .
3 CHECK HARNESS. Turn the ignition switch to ON. Using the tester, measure the voltage between terminals. Connector & terminal (i172) No. 1 (+) - No. 2 (-):	Is the voltage 4.5 - 5.0 V?	Check the connection of the evaporator sensor circuit.	Go to step 4 .
4 CHECK HARNESS. Disconnect the connector from A/C CM. Using a tester, check continuity between terminals. Connector & terminal (i172) No. 1 - No. 2:	Is there continuity?	Repair or replace the short circuit of the harness.	Replace the A/C CM. Refer to REMOVAL .