Nissan Maxima Service and Repair Manual: B2578, B2579 in-vehicle sensor

Description

In-vehicle Sensor

• The in-vehicle sensor (1) is located on instrument lower cover (LH).
• It converts variations in compartment air temperature drawn from the aspirator into a resistance value. It is then input into the A/C auto amp.

In-vehicle Sensor Circuit

Aspirator

The aspirator (1) is located on driver side of heater & cooling unit assembly. It produces vacuum pressure due to air discharged from the heater & cooling unit assembly, continuously taking compartment air in the aspirator.

DTC Logic

DTC DETECTION LOGIC

NOTE: If DTC is displayed along with DTC U1000 or U1010, first diagnose the DTC U1000 or U1010.

DTC CONFIRMATION PROCEDURE

1.CHECK WITH SELF-DIAGNOSIS FUNCTION OF CONSULT

1. Using CONSULT, perform "SELF-DIAGNOSIS RESULTS" of HVAC.
2. Check if any DTC No. is displayed in the self-diagnosis results.

NOTE: If DTC is displayed along with DTC U1000 or U1010, first diagnose the DTC U1000 or U1010.

Diagnosis Procedure

1.CHECK IN-VEHICLE SENSOR POWER SUPPLY

1. Disconnect in-vehicle sensor connector.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector M34 terminal 1 and ground.

1 - Ground: Approx. 5V

2.CHECK CONTINUITY BETWEEN IN-VEHICLE SENSOR AND A/C AUTO AMP.

1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between in-vehicle sensor harness connector M34 (A) terminal 2 and A/C auto amp. harness connector M37 (B) terminal 37.

2 - 37: Continuity should exist.

3.CHECK IN-VEHICLE SENSOR

Check in-vehicle sensor.

4.CHECK CONTINUITY BETWEEN IN-VEHICLE SENSOR AND A/C AUTO AMP.

1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector.
3. Check continuity between in-vehicle sensor harness connector M34 (A) terminal 1 and A/C auto amp. harness connector M37 (B) terminal 36.

1 - 36: Continuity should exist.

4. Check continuity between in-vehicle sensor harness connector M34 (A) terminal 1 and ground.

1 - Ground: Continuity should not exist.

Component Inspection

1.CHECK IN-VEHICLE SENSOR

1. Turn ignition switch OFF.
2. Disconnect in-vehicle sensor connector.
3. Check resistance between in-vehicle sensor terminals.