LSS V6-3.8L VIN K (1997)
Ambient Temperature Sensor / Switch HVAC: Description and Operation
Outside Temperature Sensor
This sensor is located in front of the radiator. The sensor data is processed by the HVAC Programmer and displayed on the HVAC control assembly.
During periods of city traffic and idle conditions, engine heat can surround the area of the outside temperature sensor and cause temperature readings that
are higher than the actual outside air temperature. To help eliminate these "false" readings, programming techniques are used to minimize unwanted
temperature variations.
A temperature "memory" feature is used in the programmer outside temperature programming to help provide greater accuracy under engine restart
conditions. If engine coolant temperature is less than 10°C (18°F) above the outside temperature sensor reading, the actual sensed outside temperature is
displayed. However, if engine coolant is greater than 10°C (18°F) above the sensor reading, "memorized" outside temperature is displayed. This is the
displayed temperature sensed when the engine was previously operating. At car speeds greater than 20 mph, the outside temperature display may be
allowed to increase, but only after a built-in 80 second time delay which allows for outside air to cool the sensor. The 80 second time delay starts when
vehicle speed reaches or maintains at least 20 mph. If the sensor reading is ever less than the displayed value or if the vehicle speed is 45 mph or greater,
there is no delay and outside temperature changes are displayed as rapidly as possible.
The outside temperature display can be updated by pressing "AUTO", "A/C" ("VENT" on Buick), and "RECIRC" buttons simultaneously.
