FX45 AWD V8-4.5L (VK45DE) (2006)
Ambient Temperature Sensor / Switch HVAC: Testing and Inspection
Ambient Sensor Circuit
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the hood lock stay. 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 degree C (0.6 degree 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 grille area, location of the
ambient sensor.
Diagnostic Procedure For Ambient Sensor (Step 1)