Key Switch Signal Circuit Check

Key Switch Signal Circuit Check

Description

Transmits a key switch signal to the BCM.

Component Function Check

1. CHECK BCM INPUT SIGNAL

Select "Data list" for "BCM" and check the "KEY ON SW" monitor value.






Is the inspection result normal?
YES
Inspection End.
NO
Refer to "Diagnosis Procedure".

Diagnosis Procedure

Regarding Wiring Diagram information, refer to [Warning Chime System: Wiring Diagram] [1][2]Audible Warning Device.

1. CHECK FUSE

Check if the key switch 10 A fuse [No. 25, located in the fuse and fusible link box] is blown.

Is the fuse blown?
YES
Be sure to repair the cause of malfunction before installing new fuse.
NO
GO TO 2

2. CHECK BCM INPUT SIGNAL

Check voltage between BCM harness connector M18 terminal 37 and ground.











Is the inspection result normal?
YES
Inspection End.
NO
GO TO 3

3. CHECK KEY SWITCH CIRCUIT

1 Disconnect BCM connector M18 and key switch connector.





2 Check continuity between BCM harness connector M18 (A) terminal 37 and key switch harness connector M27 (B) terminal 1.






3 Check continuity between BCM harness connector M18 (A) terminal 37 and ground.






Is the inspection result normal?
YES
GO TO 4
NO
Repair or replace harness.

4. CHECK KEY SWITCH POWER SUPPLY CIRCUIT

Check voltage between key switch harness connector M27 terminal 2 and ground.











Is the inspection result normal?
YES
Replace key switch.
NO
Repair or replace harness.

Component Inspection

1. CHECK KEY SWITCH

1 Turn ignition switch OFF.





2 Disconnect key switch.
3 Check continuity between key switch terminals 1 and 2.






Is the inspection result normal?
YES
Inspection End.
NO
Replace key switch.