B1241

DOOR LOCK: POWER DOOR LOCK CONTROL SYSTEM: B1241: Body ECU Switch Circuit Diagnosis

DTC B1241 - Body ECU Switch Circuit Diagnosis

DESCRIPTION

DTC B1241 output when: 1) the door control switches of the master switch or the door control switch on the passenger side door are pressed, or 2) when the door lock and unlock switch (door key-linked switch) built into the front door lock LH is used. DTC B1241 disappears when the switches are not pressed or used.
A malfunction is occurring when:

- The DTC is output when a switch is not operated. The switch may be stuck ON.
- The switch is not output when a switch is being operated. The switch's contact may be faulty.









WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (DOOR)
(a) Remove the DOOR fuse from the driver side junction block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (DOOR CONTROL SWITCH)
(a) Check the Data List for proper functioning of the door control switch.
Main Body ECU:






OK:
ON (door is locked/unlocked) appears on the screen.
NG -- INSPECT POWER WINDOW REGULATOR MASTER SWITCH (DOOR CONTROL SWITCH)
OK -- Continue to next step.

3. CHECK DOOR LOCK / UNLOCK FUNCTION (OPERATE VIA DRIVER SIDE DOOR KEY CYLINDER)
(a) Refer to "all doors lock / unlock functions do not operate via driver side door key cylinder" All Doors Lock / Unlock Functions Do Not Operate Via Driver Side Door Key Cylinder.
OK:
Normal operation
OK -- CHECK DOOR CONTROL SWITCH
NG -- REPLACE FRONT DOOR LOCK ASSEMBLY LH
4. INSPECT POWER WINDOW REGULATOR MASTER SWITCH (DOOR CONTROL SWITCH)




(a) Measure the resistance of the switch.
Standard resistance:






NG -- REPLACE POWER WINDOW REGULATOR MASTER SWITCH
OK -- Continue to next step.

5. CHECK WIRE HARNESS (SWITCH - ECU AND BODY GROUND)




(a) Disconnect the P17 switch connector.
(b) Disconnect the 1H junction block connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

6. CHECK DOOR CONTROL SWITCH
(a) Press the lock switch on the passenger side door control switch and check that all the doors lock. Press the unlock switch on the passenger side door control switch and check that all the doors unlock.
OK:
All doors lock/unlock when lock/unlock switches are pressed.
OK -- CHECK WIRE HARNESS (DRIVER SIDE JUNCTION LOCK - BATTERY AND BODY GROUND)
NG -- Continue to next step.

7. INSPECT DOOR CONTROL SWITCH




(a) Measure the resistance of the switch.
Standard resistance:






NG -- REPLACE DOOR CONTROL SWITCH
OK -- Continue to next step.

8. CHECK WIRE HARNESS (SWITCH - ECU AND BODY GROUND)




(a) Disconnect the D11 switch connector.
(b) Disconnect the 1H junction block connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

9. CHECK WIRE HARNESS (DRIVER SIDE JUNCTION LOCK - BATTERY AND BODY GROUND)




(a) Disconnect the 1A, 1B and 1E junction block connectors.
(b) Measure the voltage of the wire harness side connector.
Standard voltage:





(c) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE DRIVER SIDE JUNCTION BLOCK