Intake Air Temperature Switch

1. Connect voltmeter between terminals 4 and 10.
a. With air temperature -8°C (+18°F) and below, battery voltage should be present.
b. With air temperature of 4°C (39°F) and above, 0 VDC should be present.

Note: Cars with manual transmissions do not have air temp. sensors. The wire plugs for the air temp. sensor are connected together.

2. If the voltage reading is not within specification, check resistance between terminals 2 and 10. With the air temp. sensor plugs connected together, resistance should be approx. 0 Ohms. Repair wiring as necessary.

3. Check resistance between the terminals of the air temp. sensor. Resistance should be:

With air temperature at -8°C (+18°F) and below 0 Ohms
With air temperature at 4°C (39°F) and above 100K Ohms

If resistance is not within specification, replace the air temp. sensor.