Nissan Altima (L32) 2007-2012 Service Manual: Ambient sensor

Description

COMPONENT DESCRIPTION

Ambient Sensor

The ambient sensor (1) is attached on the front bumper reinforcement.

It detects ambient temperature and converts it into a resistance value which is then input into the front air control.

AMBIENT TEMPERATURE INPUT PROCESS

The automatic amplifier includes a processing circuit for the ambient sensor input. However, when the temperature detected by the ambient sensor increases quickly, the processing circuit retards the front air control function.

It only allows the front air control to recognize an ambient temperature increase of 0.33°C (0.6°F) per 100 seconds.

As an example, consider stopping for a cup of coffee after high speed driving. Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor will increase. This is because the heat from the engine compartment can radiate to the front grille area, location of the ambient sensor.

Diagnosis Procedure

DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR

SYMPTOM: Ambient sensor circuit is open or shorted.

1.CHECK VOLTAGE BETWEEN AMBIENT SENSOR HARNESS CONNECTOR AND BODY GROUND

1. Disconnect ambient sensor connector.

2. Press ignition switch ON.

3. Check voltage between ambient sensor harness connector E211 terminal 1 and ground.

Is the inspection result normal? YES >> GO TO 2

NO >> GO TO 4

2.CHECK AMBIENT SENSOR GROUND CIRCUIT BETWEEN AMBIENT SENSOR AND IPDM E/R

1. Press ignition switch OFF.

2. Disconnect IPDM E/R connector E201.

3. Check continuity between IPDM E/R harness connector M201 (A) terminal 99 and ambient sensor harness connector E211 (B) terminal 2.

If OK, check harness for short.

Is the inspection result normal? YES >> GO TO 3

NO >> Repair harness or connector.

3.CHECK AMBIENT SENSOR

Check ambient sensor. Refer to HAC-51, "Component Inspection" Is the inspection result normal? YES >> 1. Replace front air control. Refer to VTL-8, "Removal and Installation".

2. Confirm system operation.

NO >> Replace ambient sensor. Refer to HA-43, "Removal and Installation".

4.CHECK AMBIENT SENSOR CIRCUIT BETWEEN AMBIENT SENSOR AND IPDM E/R

1. Press ignition switch OFF.

2. Disconnect IPDM E/R connector E201.

3. Check continuity between IPDM E/R harness connector E201 (A) terminal 100 and ambient sensor harness connector E211 (B) terminal 1.

If OK, check harness for short.

Is the inspection result normal? YES >> 1. Replace IPDM E/R. Refer to PCS-48, "Removal and Installation".

2. Confirm system operation.

NO >> Repair harness or connector.

Component Inspection

Ambient Sensor

After disconnecting ambient sensor (1) harness connector E1, measure resistance between terminals 2 and 1 at sensor side, using the table below.

If NG, replace ambient sensor. Refer to HA-43, "Removal and Installation".