DTC Troubleshooting: B1234 (B-A2), B1234 (41)

DTC B1234 or DTC screen B-A2 or DTC indicator 41  : A short in the air mix control motor circuit (driver's)

NOTE:  If other short circuit DTCs are indicated at the same time, there may be an open or short to body ground in the power (5 V) circuit.

DTCs (AC)

1. 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
   B1234 A short in the air mix control motor circuit (driver's)

   Is DTC B1234 or Error on the DTC screen B-A2 (climate control panel without display) or 41 (climate control panel with display) indicated?

   YES 

   Go to step 2.

   NO 

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

   NO 

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

2. Determine possible failure area (S5V line, others)

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

   -2. Disconnect the following connector.

   Without dual zone control: Air mix control motor 5P connector

   With dual zone control: Driver's air mix control motor 5P connector

   -3. Turn the vehicle to the ON mode.

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

   Without dual zone control 

   Test condition	Vehicle ON mode
   	Air mix control motor 5P connector: disconnected
   Test point 1	Air mix control motor 5P connector (female terminals) No. 3:
   Test point 2	Body ground

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

   With dual zone control 

   Test condition	Vehicle ON mode
   	Driver's air mix control motor 5P connector: disconnected
   Test point 1	Driver's air mix control motor 5P connector (female terminals) No. 1:
   Test point 2	Body ground

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

   Is there about 5 V?

   YES 

   The S5V wire is OK. Go to step 3.

   NO 

   Go to step 4.

3. Determine possible failure area (air mix control motor (without dual zone control) or driver's air mix control motor (with dual zone control) check, others)

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

   Without dual zone control 

   Test condition	Vehicle ON mode
   	Air mix control motor 5P connector: disconnected
   Test point 1	Air mix control motor 5P connector (female terminals) No. 2:
   Test point 2	Body ground

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

   With dual zone control 

   Test condition	Vehicle ON mode
   	Driver's air mix control motor 5P connector: disconnected
   Test point 1	Driver's air mix control motor 5P connector (female terminals) No. 2:
   Test point 2	Body ground

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

   Is there about 5 V?

   YES 

   Replace the air mix control motor (without dual zone control) or driver's air mix control motor (with dual zone control) .

   NO 

   Go to step  6.

4. Open wire check (S5V line)

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

   Without dual zone control 

   Test condition	Vehicle ON mode
   	Air mix control motor 5P connector: disconnected

   Test point 1	Climate control unit connector B (24P) No. 1
   Test point 2	Body ground

   With dual zone control 

   Test condition	Vehicle ON mode
   	Driver's air mix control motor 5P connector: disconnected
   Test point 1	Climate control unit connector B (24P) No. 1
   Test point 2	Body ground

   Is there about 5 V?

   YES 

   Repair an open in the S5V wire.

   NO 

   The S5V wire is not open. Go to step 5.

5. Shorted wire check (S5V line)

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

   -2. Disconnect the following connector.

   Climate control unit connector B (24P)

   -3. Check for continuity between test points 1 and 2.

   Without dual zone control 

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector B (24P): disconnected
   	Air mix control motor 5P connector: disconnected
   Test point 1	Climate control unit connector B (24P) No. 1
   Test point 2	Body ground

   With dual zone control 

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector B (24P): disconnected
   	Driver's air mix control motor 5P connector: disconnected
   Test point 1	Climate control unit connector B (24P) No. 1
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to ground in the S5V wire.

   NO 

   Replace the climate control unit .

6. Shorted wire check (AMD-P-DR line)

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

   -2. Disconnect the following connector.

   Climate control unit connector B (24P)

   -3. Check for continuity between test points 1 and 2.

   Without dual zone control 

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector B (24P): disconnected
   	Air mix control motor 5P connector: disconnected
   Test point 1	Climate control unit connector B (24P) No. 2
   Test point 2	Body ground

   With dual zone control 

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector B (24P): disconnected
   	Driver's air mix control motor 5P connector: disconnected
   Test point 1	Climate control unit connector B (24P) No. 2
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to ground in the AMD-P-DR wire.

   NO 

   Replace the climate control unit .