Vehicle Outside

• Vehicle parked more than 2 hours: The OAT updates to the current sensor reading
• Vehicle parked less than 2 hours AND the new reading is LESS than the vehicle shutdown reading: The OAT updates to the current reading.
• Vehicle parked less than 2 hours AND the new reading is MORE than the vehicle shutdown reading: The vehicle will startup with the shutdown reading. As the vehicle is driven at speeds over 19 mph (30 km/h) the filter counter starts to count up. When vehicle speed is under 19 mph (30 km/h) the filter counter counts down. Once the counter reaches a predetermined maximum, the old OAT is updated to the current OAT reading.
• Example 1: Vehicle is OFF for 1 hour, OAT is 70 degrees F (21 degrees C). The ambient temperature has increased during the shut down to 74 degrees F (23 degrees C). The vehicle is started, OAT will still be displayed at 70 degrees F (21 degrees C), the driver drives at a stable speed over 19 mph (30 km/h) for a minimum of 3 to 8 minutes with no stops, OAT display updates to current temp of 74 degrees F (23 degrees C).
• Example 2: Vehicle is shutoff for 1 hour, OAT is 70 degrees F (21 degrees C). The outside temperature has increased during the shut down to 74 degrees F (23 degrees C). The vehicle is started, OAT will still be clamped at 70 degrees F (21 degrees C). However, this time the driver is in heavy city traffic driving for 10 minutes of speeds below 19 mph (30 km/h), then drives on the highway at speeds above 19 mph (30 km/h) for a minimum of 2 to 6 minutes. The OAT display updates to the current temp of 74 degrees F (23 degrees C). This time it took longer to update because of all the stop and go driving below 19 mph (30 km/h).

Since the Ambient Air Temperature Sensor is in the grille, the values must be filtered to prevent them from updating to false readings when there is engine heat or road heat.