DTC Troubleshooting: B1240 (B-B3), B1240 (4b)
DTC B1240 or DTC screen B-B3 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
  

1.
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 Error on the DTC screen B-B3 (climate control panel without display) or 4b (climate control panel with display) indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure. Check for loose wires or poor connections on the mode control motor circuit.?
2.
Open wire check (M-DEF line):

Open wire check (M-DEF line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Climate control unit connector B (24P)
Mode control motor 5P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector B (24P): disconnected
Mode control motor 5P connector: disconnected
Test point 1
Climate control unit connector B (24P) No. 20
Test point 2
Mode control motor 5P connector (female terminals) No. 5:


Is there continuity?

     
YES
     
     
     
The M-DEF wire is not open. Go to step 3.
     
NO
     
     
     
Repair an open in the M-DEF wire.?
3.
Open wire check (M-VENT line):

Open wire check (M-VENT line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector B (24P): disconnected
Mode control motor 5P connector: disconnected
Test point 1
Climate control unit connector B (24P) No. 19
Test point 2
Mode control motor 5P connector (female terminals) No. 4:


Is there continuity?

     
YES
     
     
     
The M-VENT wire is not open. Go to step 4.
     
NO
     
     
     
Repair an open in the M-VENT wire.?
4.
Shorted wire check (M-DEF line):

Shorted wire check (M-DEF line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector B (24P): disconnected
Mode control motor 5P connector: disconnected
Test point 1
Climate control unit connector B (24P) No. 20
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the M-DEF wire.?
     
NO
     
     
     
The M-DEF wire is OK. Go to step 5.
5.
Shorted wire check (M-VENT line):

Shorted wire check (M-VENT line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit connector B (24P): disconnected
Mode control motor 5P connector: disconnected
Test point 1
Climate control unit connector B (24P) No. 19
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the M-VENT wire.?
     
NO
     
     
     
The M-VENT wire is OK. Go to step 6.
6.
Mode control motor check:

Mode control motor check
?1.
Test the mode control motor.

Is the mode control motor OK?

     
YES
     
     
     
     
NO
     
     
     
Replace the mode control motor, or repair the mode control linkage or door.?