DTC B1221 (8)

DTC B1221 or DTC indicator 8  : An Open in the Rear Mode Control Motor Circuit

DTCs (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 HVAC control unit.

   - 4. Wait for at least 8 seconds.

   - 5. Check for DTCs.

   DTC Description	DTC
   B1221 An open in the rear mode control motor circuit

   Is DTC B1221 or 8 indicated?

   YES 

   Go to step 2.

   NO 

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

2. Determine possible failure area (MOD-P RR line, others)

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

   - 2. Disconnect the following connector.

   Rear mode 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
   	Rear mode control motor 7P connector: disconnected
   Test point 1	Rear mode 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 MOD-P RR 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
   	Rear mode control motor 7P connector: disconnected
   Test point 1	Rear mode control motor 7P connector No. 2
   Test point 2	Rear mode control motor 7P connector No. 3

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

   Is there about 5 V?

   YES 

   Replace the rear mode control motor .

   NO 

   Repair an open in the wire between the HVAC control unit and the rear mode control motor.

4. Open wire check (MOD-P RR line)

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

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

   Is there about 5 V?

   YES 

   Repair an open in the wire between the HVAC control unit and the rear mode control motor.

   NO 

   Replace the HVAC control unit .