In-Vehicle Sensor Circuit

TROUBLE DIAGNOSIS


In-vehicle Sensor Circuit


COMPONENT DESCRIPTION

In-vehicle Sensor
The in-vehicle sensor (1) is located on instrument lower driver panel.





It converts variations in temperature of passenger compartment air
(drawn in through the integrated fan) into a value. It is then input into the front air control.






DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circuit is open or shorted. Using the CONSULT-III, DTC B2578 or B2579 is displayed. Without a CONSULT-III, code 30 or 31 is indicated on front air control as a result of conducting the front air control self-diagnosis.
SYMPTOM: In-vehicle sensor motor circuit is open or shorted. Using the CONSULT-III, DTC B2570 or B257E is displayed. Without a CONSULT-III, code 44 or 46 is indicated on front air control as a result of conducting the front air control self-diagnosis
1.CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
Self-diagnosis DTC B2578 or B2579 (with CONSULT-III) or code 30 or 31 (without CONSULT-III) is present. Refer to CONSULT-III Function (HVAC).
Yes or No
Yes - GO TO 2.
No - GO TO 6.
2.CHECK IN-VEHICLE SENSOR VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect in-vehicle sensor connector.
3. Turn ignition switch ON.





4. Check voltage between in-vehicle sensor harness connector M32 terminal 1 and ground.

Approx. 5V.

OK or NG
OK - GO TO 3.
NG - GO TO 5.
3.CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL





1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between in-vehicle sensor harness connector M32 (B) terminal 4 and front air control harness connector M49 (A) terminal 26.

Continuity should exist.

4. Check continuity between in-vehicle sensor harness connector M32 (A) terminal 4 and ground.

Continuity should not exist.

OK or NG
OK - GO TO 4.
NG - Repair harness or connector.
4.CHECK IN-VEHICLE SENSOR
Check in-vehicle sensor. Refer to "COMPONENT INSPECTION" for in-vehicle Sensor.
OK or NG
OK - 1. Replace front air control. Refer to Service and Repair.
2. Go to A/C System Self-Diagnosis Function and perform self-diagnosis.
NG - 1. Replace in-vehicle sensor. Refer to In-Vehicle Sensor.
2. Go to A/C System Self-Diagnosis Function and perform self-diagnosis.
5.CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL





1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between in-vehicle sensor harness connector M32 (B) terminal 1 and front air control harness connector M50 (A) terminal 32.

Continuity should exist.

4. Check continuity between in-vehicle sensor harness connector M32 (A) terminal 1 and ground.

Continuity should not exist.

OK or NG
OK - 1. Replace front air control. Refer to Service and Repair.
2. Go to self-diagnosis A/C System Self-Diagnosis Function and perform self-diagnosis.
NG - Repair harness or connector.
6.CHECK IN-VEHICLE SENSOR MOTOR VOLTAGE (SELF-DIAGNOSIS CODES 44 OR 46)





1. Turn ignition switch OFF.
2. Disconnect in-vehicle sensor connector.
3. Turn ignition switch ON.
4. Check voltage between in-vehicle sensor harness connector M32 terminal 3 and ground.

Battery voltage should exist.

OK or NG
OK - GO TO 7.
NG - GO TO 8.
7.CHECK IN-VEHICLE SENSOR MOTOR GROUND CIRCUIT (SELF-DIAGNOSIS CODES 44 OR 46)





Check continuity between in-vehicle sensor harness connector M32 terminal 2 and ground.

Continuity should exist.

OK or NG
OK - Replace the in-vehicle sensor. Refer to In-Vehicle Sensor.
NG - Repair harness or connector.
8.CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR MOTOR AND FRONT AIR CONTROL (SELF-DIAGNOSIS CODES 44 OR 46)





1. Disconnect front air control connector.
2. Check continuity between in-vehicle sensor harness connector M32 (B) terminal 3 and front air control harness connector M50 (A) terminal 31.

Continuity should exist.

OK or NG
OK - Replace the front air control. Refer to Service and Repair.
NG - Repair harness or connector.

COMPONENT INSPECTION

In-vehicle Sensor






After disconnecting in-vehicle sensor (1) connector, measure resistance between terminals 1 and 4 at sensor component side, using the table below.






If NG, replace in-vehicle sensor. Refer to In-Vehicle Sensor.