Test B: The Outside Air Temperature Is Inaccurate / Inoperative

PINPOINT TEST B: THE OUTSIDE AIR TEMPERATURE IS INACCURATE/INOPERATIVE

B1-B3:

B4-B6:

B7:

Normal Operation
The compass and temperature display can be turned on and off by pressing the SELECT switch in the overhead console.

The temperature can be displayed in Celsius or Fahrenheit by pressing the SELECT switch.

The outside air temperature display receives temperature input from the ambient air temperature sensor through circuits 470 (PK/BK) and 767 (LB/OG). If the circuits are shorted or open, then the display shows 60°C (140°F) (shorted), or -40°C (-40°F) (open).

The temperature display receives voltage from the central junction box (CJB) through circuit 137 (YE/BK). Ground for the temperature display is provided by circuit 875 (BK/LB).

Possible Causes
- Circuit 470 (PK/BK) short to ground or open
- Circuit 767 (LB/OG) short to ground or open
- Compass display (includes ambient air temperature display)
- Ambient air temperature sensor