Key Cylinder Switch Circuit Check [Driver Side]

Key Cylinder Switch Circuit Check [Driver Side]

Description

The main power window and door lock/unlock switch detects condition of the door key cylinder switch and transmits to BCM as the LOCK or UNLOCK signal.

Component Function Check

1. CHECK DOOR KEY CYLINDER SWITCH INPUT SIGNAL

Check "KEY CYL LK-SW" AND "KEY CYL UN-SW" in data list mode for "DOOR LOCK" with SDT.






Is the inspection result normal?
YES
Key cylinder switch is OK.
NO
Refer to "Diagnosis Procedure".

Diagnosis Procedure

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 DOOR KEY CYLINDER SWITCH LH

With SDT

Check front door lock assembly LH (key cylinder switch) ("KEY CYL LK-SW") and ("KEY CYL UN-SW) in data list mode in SDT. Refer to [SDT Function (BCM - DOOR LOCK)] SDT Function (BCM - Door Lock).
- When key inserted in front key cylinder is turned to LOCK:






- When key inserted in front key cylinder is turned to UNLOCK:






Without SDT

Check voltage between BCM connector M18 terminals 7, 8 and ground.











Is the inspection result normal?
YES
Front door lock assembly LH (key cylinder switch) signal is OK.
NO
GO TO 2

2. CHECK FRONT DOOR LOCK ASSEMBLY LH (KEY CYLINDER SWITCH)

1 Turn ignition switch OFF.
2 Disconnect front door lock assembly LH (key cylinder switch).
3 Check continuity between front door lock assembly LH (key cylinder switch) connector terminals 3, 4 and 5.











Is the inspection result normal?
YES
GO TO 3
NO
Replace front door lock assembly LH (key cylinder switch). Refer to [Front Door Lock: Removal and Installation] Front Door Lock Removal and Installation.

3. CHECK FRONT DOOR LOCK ASSEMBLY LH HARNESS

1 Disconnect BCM.
2 Check continuity between BCM connector M18 terminals 7, 8 and front door lock assembly LH connector D14 terminals 3, 5.











3 Check continuity between BCM connector M18 terminals 7, 8 and ground.






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

4. CHECK FRONT DOOR LOCK ASSEMBLY LH GROUND

Check continuity between front door lock assembly LH connector D14 terminal 4 and ground.











Is the inspection result normal?
YES
GO TO 5
NO
Repair or replace harness.

5. CHECK BCM OUTPUT VOLTAGE

1 Connect BCM.
2 Check voltage between BCM connector M18 terminals 7, 8 and ground.











Is the inspection result normal?
YES
Check condition of the harness and connector.
NO
Replace BCM. Refer to [BCM: Removal and Installation] Removal and Replacement.