DTC B2986 (L and Windshield Defrost)

DTC B2986 or DTC indicator L and WINDSHIELD DEFROST  : An Open in the Recirculation Control Motor Circuit

DTC (AC)

1. Problem verification

   - 1. Clear the DTCs 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. Wait for at least 8 seconds.

   - 5. Check for DTCs.

   DTC Description	DTC
   B2986 An open in the recirculation control motor circuit

   Is DTC B2986 or L and WINDSHIELD DEFROST indicated?

   YES 

   Go to step 2.

   NO 

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

2. Determine possible failure area (FRS REC-P line, others)

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

   - 2. Disconnect the following connector.

   Recirculation 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
   	Recirculation control motor 7P connector: disconnected
   Test point 1	Recirculation control motor 7P connector No. 2
   Test point 2	Body ground

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

   Is there about 5 V?

   YES 

   The FRS REC-P 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
   	Recirculation control motor 7P connector: disconnected
   Test point 1	Recirculation control motor 7P connector No. 2
   Test point 2	Recirculation control motor 7P connector No. 3

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

   Is there about 5 V?

   YES 

   The SENSOR(COM) wire is OK. Replace the recirculation control motor .

   NO 

   Repair an open in the wire between the climate control unit and the recirculation control motor.

4. Open wire check (FRS REC-P line)

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

   Test condition	Vehicle ON mode
   	Recirculation control motor 7P connector: disconnected
   Test point 1	Climate control unit connector C (12P) No. 5 - 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 about 5 V?

   YES 

   Repair an open in the wire between the climate control unit and the recirculation control motor.

   NO 

   The FRS REC-P wire is OK. Replace the climate control unit .