Ambient Sensor Circuit

Ambient Sensor Circuit

COMPONENT DESCRIPTION




Ambient Sensor
The ambient sensor is attached on the radiator core support (left side). It detects ambient temperature and converts it into a resistance value which is then input into the unified meter and A/C amp.

AMBIENT TEMPERATURE INPUT PROCESS
The unified meter and A/C amp. 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 unified meter and A/C amp. function. It only allows the unified meter and A/C amp. to recognize an ambient temperature increase of 0.33 °C (0.6 °F) per 100 seconds.

As an example, consider stopping for a few minutes 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 bumper area, location of the ambient sensor.

DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR




SYMPTOM: Ambient sensor circuit is open or shorted. (21 or -21 is indicated on unified meter and A/C amp. as a result of performing self-diagnosis STEP-2.)

Step 1-4:

Step 4 (Continued):

COMPONENT INSPECTION

Ambient Sensor
After disconnecting ambient sensor connector E62, measure resistance between terminals 1 and 2 at sensor side. Refer to the table below.






If NG, replace ambient sensor.