The ambient temperature sensor is located in front of the radiator. The sensor data is processed by the heater and A/C programmer. The sensor data is displayed on the heater and A/C control.
During periods of city traffic and idle conditions, the engine heat can surround the area of the ambient temperature sensor and cause temperature readings that are higher than the actual ambient air temperature. In order to help eliminate the false readings, programming techniques are used in order to minimize unwanted temperature variations.
The heater and A/C programmer ambient temperature programming uses a temperature memory feature in order to help provide greater accuracy under the engine restart conditions:
| • | The actual sensed ambient temperature displays if one of the following conditions exists: |
| - | The engine coolant temperature is less than 10°C (50°F) above the ambient temperature sensor reading. |
| - | The 2 hour ignition off timer has expired. |
| • | The memorized ambient temperature is displayed if the engine coolant is greater than 10°C (50°F) above the sensor reading. This memorized temperature is the displayed temperature which was sensed when the engine was previously operating. |
At car speeds greater than 32 km/h (20 mph), the ambient temperature display may be allowed to increase, but only after a built-in 80 second time delay which allows for the ambient air to cool the sensor. The 80 second time delay starts when the vehicle speed reaches or maintains at least 32 km/h (20 mph). The ambient temperature changes are displayed as rapidly as possible without delay if one of the following conditions exists:
| • | The sensor reading is ever less than the displayed value. |
| • | The vehicle speed is 72 km/h (45 mph) or greater. |
