DTC Troubleshooting: B1235 (42)
DTC B1235 or DTC indicator 42: A Problem in the Air Mix Control Motor Circuit, Linkage, Door, or Motor
DTC Description
DTC
B1235 A Problem in the Air Mix 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
B1235 A Problem in the Air Mix Control Motor Circuit, Linkage, Door, or Motor
  

Is DTC B1235 or 42 indicated?

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

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

?2.
Disconnect the following connectors.
Climate control unit 32P connector
Air mix 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
Air mix control motor 5P connector: disconnected
Test point 1
Climate control unit 32P connector No. 14
Test point 2
Air mix control motor 7P connector No. 5


Is there continuity?

     
YES
     
     
     
The M-HOT wire is not open. Go to step 3.
     
NO
     
     
     
Repair an open in the wire between the climate control unit and the air mix control motor.?
3.
Open wire check (M-COOL line):

Open wire check (M-COOL line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit 32P connector: disconnected
Air mix control motor 5P connector: disconnected
Test point 1
Climate control unit 32P connector No. 13
Test point 2
Air mix control motor 5P connector No. 4


Is there continuity?

     
YES
     
     
     
The M-COOL wire is not open. Go to step 4.
     
NO
     
     
     
Repair an open in the wire between the climate control unit and the air mix control motor.?
4.
Shorted wire check (M-HOT line):

Shorted wire check (M-HOT line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit 32P connector: disconnected
Air mix control motor 5P connector: disconnected
Test point 1
Climate control unit 32P connector No. 14
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire between the climate control unit and the air mix control motor.?
     
NO
     
     
     
The M-HOT wire is OK. Go to step 5.
5.
Shorted wire check (M-COOL line):

Shorted wire check (M-COOL line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Climate control unit 32P connector: disconnected
Air mix control motor 5P connector: disconnected
Test point 1
Climate control unit 32P connector No. 13
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire between the climate control unit and the air mix control motor.?
     
NO
     
     
     
The M-COOL wire is OK. Go to step 6.
6.
Air mix control motor check:

Air mix control motor check
?1.
Test the air mix control motor.

Is the air mix control motor OK?

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