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
  

1.
Problem verification:

Problem verification
?1.
Clear the DTCs with the HDS.


?2.
Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF 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.?
2.
Open wire check (MODE MTR DEF/M-DEF line):

Open wire check (MODE MTR DEF/M-DEF line)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connectors.

?3.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
Climate control unit 32P connector : disconnected
 
Mode control motor 7P connector: disconnected
Test circuit
MODE MTR DEF/M-DEF
Test point 1
Climate control unit 32P connector No. 5 (GRN)
Test point 2
Mode control motor 7P connector No. 6 (GRN)


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.?
3.
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
IG LOCK (0) or OFF mode
 
Climate control unit 32P connector: disconnected
 
Mode control motor 7P connector: disconnected
Test circuit
MODE MTR VENT/M-VENT
Test point 1
Climate control unit 32P connector No. 4 (WHT)
Test point 2
Mode control motor 7P connector No. 7 (WHT)


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.?
4.
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 individually.
Test condition
IG LOCK (0) or OFF mode
 
Climate control unit 32P connector: disconnected
 
Mode control motor 7P connector: disconnected
Test circuit
MODE MTR DEF
Test point 1
Climate control unit 32P connector No. 5 (GRN)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the climate control unit and the mode control motor.?
     
NO
     
     
     
The MODE MTR DEF/M-DEF wire is OK. Go to step 5.
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 individually.
Test condition
IG LOCK (0) or OFF mode
 
Climate control unit 32P connector: disconnected
 
Mode control motor 7P connector: disconnected
Test circuit
MODE MTR VENT
Test point 1
Climate control unit 32P connector No. 4 (WHT)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to body 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.
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 doors.?