DTC B1238 (G and Windshield Defrost)

DTC B1238 or DTC indicator G and WINDSHIELD DEFROST  : A Problem in the Passenger's Air Mix Control Motor Circuit, Linkage, Door, or Motor

DTC (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 climate control unit.

   - 4. Check for DTCs.

   DTC Description	DTC
   B1238 A problem in the passenger's air mix control motor circuit, linkage, door, or motor

   Is DTC B1238 or G and WINDSHIELD DEFROST indicated?

   YES 

   Go to step 2.

   NO 

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

2. Open wire check (M HOT AS line)

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

   - 2. Disconnect the following connectors.

   Climate control unit connector A (32P)

   Passenger's air mix control motor 7P connector

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

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector A (32P): disconnected
   	Passenger's air mix control motor 7P connector: disconnected
   Test point 1	Climate control unit connector A (32P) No. 10 - Refer to: Climate Control Unit Connector For Inputs and Outputs (2019 2020 2021), or Climate Control Unit Connector For Inputs and Outputs (2016 2017 2018)
   Test point 2	Passenger's air mix control motor 7P connector No. 6

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

   Is there continuity?

   YES 

   The M HOT AS wire is not open. Go to step 3.

   NO 

   Repair an open in the wire between the climate control unit and the passenger's air mix control motor.

3. Open wire check (M COOL AS line)

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

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector A (32P): disconnected
   	Passenger's air mix control motor 7P connector: disconnected
   Test point 1	Climate control unit connector A (32P) No. 9 - Refer to: Climate Control Unit Connector For Inputs and Outputs (2019 2020 2021), or Climate Control Unit Connector For Inputs and Outputs (2016 2017 2018)
   Test point 2	Passenger's air mix control motor 7P connector No. 7

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

   Is there continuity?

   YES 

   The M COOL AS wire is not open. Go to step 4.

   NO 

   Repair an open in the wire between the climate control unit and the passenger's air mix control motor.

4. Shorted wire check (M HOT AS line)

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

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector A (32P): disconnected
   	Passenger's air mix control motor 7P connector: disconnected
   Test point 1	Climate control unit connector A (32P) No. 10 - Refer to: Climate Control Unit Connector For Inputs and Outputs (2019 2020 2021), or Climate Control Unit Connector For Inputs and Outputs (2016 2017 2018)
   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 passenger's air mix control motor.

   NO 

   The M HOT AS wire is OK. Go to step 5.

5. Shorted wire check (M COOL AS line)

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

   Test condition	Vehicle OFF (LOCK) mode
   	Climate control unit connector A (32P): disconnected
   	Passenger's air mix control motor 7P connector: disconnected
   Test point 1	Climate control unit connector A (32P) No. 9 - Refer to: Climate Control Unit Connector For Inputs and Outputs (2019 2020 2021), or Climate Control Unit Connector For Inputs and Outputs (2016 2017 2018)
   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 passenger's air mix control motor.

   NO 

   The M COOL AS wire is OK. Go to step 6.

6. Passenger's air mix control motor check

   - 1. Test the passenger's air mix control motor.

   Is the passenger's air mix control motor OK?

   YES 

   Replace the climate control unit .

   NO 

   Replace the passenger's air mix control motor , or repair the passenger's air mix control linkage or door.