Atmospheric Pressure Sensor (Service Code 15)
If you need to check the atmospheric pressure sensor for various altitudes other than sea level,
check the output voltage as follows:
Determine the local altitude (elevation).
If you know the local atmospheric pressure using a barometer, substitute the atmospheric pressure
for Pv (Throttle Vacuum) in the inlet air pressure sensor chart (see Inlet Air Pressure Sensor section
in this chapter).
Get the usable range of the atmospheric pressure sensor output voltage in the same way as Output
Voltage Inspection of the inlet air pressure sensor and check if Va (output voltage) is within the
usable range or not.
If you know the local altitude, use the following chart.
Suppose the local altitude is 1 300 m (4 200 ft) and the sensor output voltage Va is 3.3 V.
Plot this H (1 300 m) at a point  on the following chart and draw a vertical line through the point.
Then, you can get the usable range  of the sensor output voltage.
Usable Range = 3.2
Plot Va (3.3 V) on the vertical line → Point 
Results: In the chart, Va is within the usable range and the sensor is normal.
b. Atmospheric Pressure Sensor
FUEL SYSTEM (DFI) 3-59