DTC B1233 (3) (HVAC Control Unit)

DTC B1233 or DTC indicator 3  : An open in the air mix control motor circuit (front)

DTCs (AC)

1. Problem verification

   -1. Clear the DTC with the HDS.

   -2. Turn the vehicle to the OFF (LOCK) mode, then the ON mode.

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

   -4. Wait for at least 8 seconds.

   -5. Check for DTCs.

   DTC Description	DTC
   B1233 An open in the air mix control motor circuit (front)

   Is DTC B1233 or 3 indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure. Check for loose wires or poor connections on the front air mix control motor circuit.

2. Determine possible failure area (AMDP AS line, others)

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

   -2. Disconnect the following connector.

   Front air mix control motor 7P connector

   -3. Turn the vehicle to the ON mode.

   -4. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Front air mix control motor 7P connector: disconnected
   Test point 1	Front air mix control motor 7P connector (female terminals) No. 2:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5 V?

   YES 

   The AMDP AS wire is OK. Go to step 3.

   NO 

   Go to step  4.

3. Open wire check (SENSOR (COM) line)

   -1. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Front air mix control motor 7P connector: disconnected
   Test point 1	Front air mix control motor 7P connector (female terminals) No. 2:
   Test point 2	Front air mix control motor 7P connector (female terminals) No. 3:

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5 V?

   YES 

   The SENSOR (COM) wire is OK. Replace the front air mix control motor .

   NO 

   Repair an open in the wire between the HVAC control unit and the front air mix control motor.

4. Open wire check (AMDP AS line)

   -1. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Front air mix control motor 7P connector: disconnected
   Test point 1	HVAC control unit connector C (12P) No. 2
   Test point 2	Body ground

   Is there about 5 V?

   YES 

   Repair an open in the wire between the HVAC control unit and the front air mix control motor.

   NO 

   The AMDP AS wire is OK. Replace the HVAC control unit .