B2578

B2578, B2579 IN-VEHICLE SENSOR

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.






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 IN-VEHICLE SENSOR VOLTAGE SIGNAL

1.Turn power switch ON.
2.Operate the automatic air conditioning system.
3.Read voltage signal between A/C auto amp. harness connector terminals.





Is the inspection result normal?
YES- GO TO 7.
NO- GO TO 2.

2. CHECK IN-VEHICLE SENSOR POWER SUPPLY

1.Turn power switch OFF.
2.Disconnect in-vehicle sensor connector.
3.Turn power switch ON.
4.Check voltage between in-vehicle sensor harness connector and ground.





Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 5.

3. CHECK IN-VEHICLE SENSOR GROUND CIRCUIT FOR OPEN

1.Turn power switch OFF.
2.Disconnect A/C auto amp. connector.
3.Check continuity between in-vehicle sensor 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 IN-VEHICLE SENSOR

Check in-vehicle sensor. 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 in-vehicle sensor. Refer to "Removal and Installation" Service and Repair.

5. CHECK IN-VEHICLE SENSOR POWER SUPPLY CIRCUIT FOR OPEN

1.Turn power switch OFF.
2.Disconnect A/C auto amp. connector.
3.Check continuity between in-vehicle sensor harness connector and A/C auto amp. harness connector.





Is the inspection result normal?
YES- GO TO 6.
NO- Repair harness or connector.

6. CHECK IN-VEHICLE SENSOR POWER SUPPLY CIRCUIT FOR SHORT

Check continuity between in-vehicle sensor harness connector and ground.





Is the inspection result normal?
YES- Replace A/C control (A/C auto amp.). Refer to "Removal and Installation" Service and Repair.
NO- Repair harness or connector.

7. CHECK INTERMITTENT INCIDENT

Check intermittent incident. Refer to "Intermittent Incident" Intermittent Incident.
Is the inspection result normal?
YES- Replace A/C control (A/C auto amp.). Refer to "Removal and Installation" Service and Repair.
NO- Repair or replace malfunctioning parts.


Component Inspection


1. CHECK IN-VEHICLE SENSOR

1.Remove in-vehicle sensor. Refer to "Removal and Installation" Service and Repair.
2.Check resistance between in-vehicle sensor terminals. Refer to applicable table for the normal value.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace in-vehicle sensor. Refer to "Removal and Installation" Service and Repair.