DTC Troubleshooting: B1240 (4B)

DTC B1240 or DTC indicator 4b: A Problem in the Mode Control Motor Circuit, Linkage, Door, or Motor

DTC Description	DTC
B1240 A Problem in the Mode Control Motor Circuit, Linkage, Door, or Motor

Problem verification:

Problem verification

?1.	Clear the DTCs with the HDS.

?2.	Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

?3.	Do the Self-Diagnostic Function with the HDS or the climate control unit.

?4.

Check for DTCs.

DTC Description	DTC
B1240 A Problem in the Mode Control Motor Circuit, Linkage, Door, or Motor

Is DTC B1240 or 4b indicated?


	YES

Go to step 2.


	NO

Intermittent failure. Check for loose wires or poor connections on the mode control motor circuit.?

Open wire check (MODE MTR DEF/M-DEF line):

Open wire check (MODE MTR DEF/M-DEF line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Disconnect the following connectors.

Climate control unit 32P connector

Mode control motor 5P connector

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Climate control unit 32P connector: disconnected
	Mode control motor 5P connector: disconnected
Test point 1	Climate control unit 32P connector No. 12
Test point 2	Mode control motor 5P connector No. 4

Is there continuity?


	YES

The MODE MTR DEF/M-DEF wire is not open. Go to step 3.


	NO

Repair an open in the wire between the climate control unit and the mode control motor.?

Open wire check (MODE MTR VENT/M-VENT line):

Open wire check (MODE MTR VENT/M-VENT line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Climate control unit 32P connector: disconnected
	Mode control motor 5P connector: disconnected
Test point 1	Climate control unit 32P connector No. 11
Test point 2	Mode control motor 5P connector No. 5

Is there continuity?


	YES

The MODE MTR VENT/M-VENT wire is not open. Go to step 4.


	NO

Repair an open in the wire between the climate control unit and the mode control motor.?

Shorted wire check (MODE MTR DEF/M-DEF line):

Shorted wire check (MODE MTR DEF/M-DEF line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Climate control unit 32P connector: disconnected
	Mode control motor 5P connector: disconnected
Test point 1	Climate control unit 32P connector No. 12
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to ground in the wire between the climate control unit and the mode control motor.?


	NO

The MODE MTR DEF/M-DEF is OK. Go to step 5.

Shorted wire check (MODE MTR VENT/M-VENT line):

Shorted wire check (MODE MTR VENT/M-VENT line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Climate control unit 32P connector: disconnected
	Mode control motor 5P connector: disconnected
Test point 1	Climate control unit 32P connector No. 11
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to ground in the wire between the climate control unit and the mode control motor.?


	NO

The MODE MTR VENT/M-VENT wire is OK. Go to step 6.

Mode control motor check:

Mode control motor check

?1.	Test the mode control motor.

Is the mode control motor OK?


	YES

Replace the climate control unit.?


	NO

Replace the mode control motor, or repair the mode control linkage or door.?