Key Switch (BCM Input) Circuit Check

Key Switch (BCM Input) Circuit Check

Regarding Wiring Diagram information, refer to [Power Door Lock System: Wiring Diagram [King Cab] Power Door Lock System [King Cab] ] or [Power Door Lock System: Wiring Diagram [Crew Cab] Power Door Lock System [Crew Cab] ].

1. CHECK KEY SWITCH INPUT SIGNAL

With SDT

Check key switch "KEY ON SW" in data list mode with SDT. Refer to [SDT Function (BCM - DOOR LOCK)] SDT Function (BCM - Door Lock).
- When key is inserted to ignition key cylinder:






- When key is removed from ignition key cylinder:






Without SDT

Check voltage between BCM connector M18 terminal 37 and ground.











Is the inspection result normal?
YES
Key switch (insert) circuit is OK.
NO
GO TO 2

2. CHECK KEY SWITCH (INSERT)

1 Turn ignition switch OFF.
2 Disconnect key switch connector.
3 Check continuity between key switch terminals.










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