B257B

B257B, B257C AMBIENT 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. Refer to HAC56, "DTC Logic".






DTC CONFIRMATION PROCEDURE


1. PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT
1.Turn ignition switch ON.
2.Using CONSULT, perform "SELF-DIAGNOSIS RESULTS" of HVAC.
3.Check if any DTC No. is displayed in the self-diagnosis results.
Is DTC detected?
YES- Refer to "Diagnosis Procedure" .
NO- Inspection End.


Diagnosis Procedure

Regarding Wiring Diagram information, refer to "Wiring Diagram" Automatic Air Conditioning.

1. CHECK AMBIENT SENSOR POWER SUPPLY

1.Turn ignition switch OFF.
2.Disconnect ambient sensor connector.
3.Turn ignition switch ON.
4.Check voltage between ambient sensor harness connector and ground.





Is the inspection result normal?
YES- GO TO 2.
NO- GO TO 4.

2. CHECK AMBIENT SENSOR GROUND CIRCUIT

1.Turn ignition switch OFF.
2.Check continuity between ambient sensor harness connector and ground.





Is the inspection result normal?
YES- GO TO 3.
NO- Repair harness or connector.

3. CHECK AMBIENT SENSOR

Check ambient sensor. Refer to "Component Inspection" .
Is the inspection result normal?
YES- Replace A/C auto amp. Refer to "Removal and Installation" Removal And Installation.
NO- Replace ambient sensor. Refer to "Removal and Installation" Automatic Air Conditioning.

4. CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR OPEN

1.Turn ignition switch OFF.
2.Disconnect A/C auto amp.connector.
3.Check continuity between ambient sensor 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 AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR GROUND SHORT

Check continuity between ambient sensor harness connector and ground.





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

6. CHECK AMBIENT SENSOR POWER SUPPLY CIRCUIT FOR POWER SHORT

1.Turn ignition switch ON.
2.Check voltage between ambient sensor harness connector and ground.





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


Component Inspection


1. CHECK AMBIENT SENSOR

1.Turn ignition switch OFF.
2.Disconnect ambient sensor connector.
3.Check resistance between ambient sensor terminals.





Is the inspection result normal?
YES- Inspection End.
NO- Replace ambient sensor. Refer to "Removal and Installation" Automatic Air Conditioning.