Check Ignition Switch Circuit

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, display the following items in the [Data monitor] of [Body Control]. Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR .
   • [IGN voltage]
   • [BATT voltage (control)]

Does the [IGN voltage] indicate 0 V when the ignition switch is OFF, and fall within a range of ±1 V from the [BATT voltage (control)] when the ignition switch is ON?

Yes:  The ignition switch input circuit is OK.

No:  Go to  2.

1. Turn the ignition switch to OFF.
2. Check the F/B fuse No. 5 and M/B fuse No. 6.

Is the check result OK?

Yes:  Go to  3.

No:  Replace the defective fuse.

1. Disconnect the F/B connector.
2. Measure the voltage between F/B connector and chassis ground.

   Connector & terminal 

   (B8) No. 8 (+) - Chassis ground (-):

Is the voltage 8.5 - 16.5 V?

Yes:  Inspect the power supply switching system in Diagnostics with Phenomenon. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON>LIST>POWER SUPPLY SWITCHING SYSTEM .

When no fault is found in the power supply switching system: Go to  4.

No:  Check the DC power supply circuit.

1. Disconnect the connector of body integrated unit.
2. Check the F/B and body integrated unit connector.

Is there poor contact of connector?

Yes:  Repair or replace the poor contact of connector.

No:  Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .