D 250 Pickup L6-359 5.9L DSL (1992)
Intake Air Temperature Sensor: Testing and Inspection
Air Temperature Switch
1.
Disconnect the 2-way charge air temperature sensor electrical connector.
2.
Turn the ignition switch to the ON position.
3.
The following should occur:
^
The Wait-To-Start light will illuminate and the air intake heater solenoids will click (The air intake heater solenoids should click every time
the Wait-To-Start light illuminates).
^
The Wait-To-Start light will remain illuminated for 20 seconds. After 20 seconds, the Wait-To-Start light will turn off and the air intake
heater relays will click off.
^
The Wait-To-Start light will remain off for another 20 seconds, then the Wait-To-Start light will start flashing. The light starts flashing to
indicate that the charge air temperature circuit is open (because the electrical connector is disconnected).
If the light does not perform exactly as previously outlined, there is a problem with the wiring harness or the electronic controller. If the light
performs exactly as outlined, the test is complete.
