B27A2

B27A2, B27A3, B27A4, B27A5 AIR MIX DOOR MOTOR

DTC Logic


DTC DETECTION LOGIC

NOTE:
- If DTC is displayed along with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to HAC55, "DTC Logic".
- If DTC is displayed along with DTC U1010, first perform the trouble diagnosis for DTC U1010. "DTC Logic" Control Unit.
- If air mix door motors DTC (B27A2 - B27A5) are detected, there is probably a disconnected connector or an open circuit in air mix door motor drive power supply harness.






DTC CONFIRMATION PROCEDURE


1. PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT
1.Turn power switch ON.
2.Select "Self Diagnostic Result" mode of "HVAC" using CONSULT.
3.Check DTC.
Is DTC detected?
YES- Refer to "Diagnosis Procedure" .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK AIR MIX DOOR MOTOR POWER SUPPLY

1.Turn power switch OFF.
2.Disconnect air mix door motor connector.
3.Turn power switch ON.
4.Check voltage between air mix door motor harness connector and ground.





Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 2.

2. CHECK A/C RELAY CIRCUIT

Check A/C relay circuit. Refer to "Diagnosis Procedure" A/C Relay.
Is the inspection result normal?
YES- Repair harness or connector between A/C relay and air mix door motor.
NO- Repair or replace error-detected parts.

3. CHECK AIR MIX DOOR MOTOR DRIVE SIGNAL CIRCUIT FOR OPEN

1.Turn power switch OFF.
2.Disconnect A/C auto amp. connector.
3.Check continuity between air mix door motor harness connector and A/C auto amp. harness connector.





Is the inspection result normal?
YES- GO TO 4.
NO- Repair harness or connector.

4. CHECK AIR MIX DOOR MOTOR DRIVE SIGNAL CIRCUIT FOR SHORT

Check continuity between air mix door motor harness connector and A/C auto amp. harness connector.





Is the inspection result normal?
YES- GO TO 5.
NO- Repair harness or connector.

5. CHECK AIR MIX DOOR MOTOR

Check air mix door motor. Refer to "Component Inspection" .
Is the inspection result normal?
YES- Replace A/C control (A/C auto amp.). Refer to "Removal and Installation" Service and Repair.
NO- Replace air mix door motor. Refer to "AIR MIX DOOR MOTOR : Removal and Installation" Air Mix Door Motor.


Component Inspection


1. CHECK AIR MIX DOOR MOTOR

1.Remove air mix door motor. Refer to "AIR MIX DOOR MOTOR : Removal and Installation" Air Mix Door Motor.
2.Check resistance between air mix door motor terminals. Refer to applicable table for the normal value.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace air mix door motor. Refer to "AIR MIX DOOR MOTOR : Removal and Installation" Air Mix Door Motor.