17-38 SELF-DIAGNOSIS SYSTEM
Atmospheric Pressure Sensor (Service Code 15)
If the wiring is good, check the sensor for various vacuum.
Determine the local altitude (elevation).
If you know the local altitude, use the chart in this section.
If you know the local atmospheric pressure using a
barometer, substitute the atmospheric pressure for Pv
(vacuum pressure) in the intake air pressure sensor
chart (see Intake Air Pressure Sensor Output Voltage
Get the usable range of the atmospheric pressure sensor
output voltage in the same way as output voltage inspec-
tion of the intake air pressure sensor and check if Va (out-
put voltage) is within the usable range or not.
If the reading is out of the usable range, replace the sen-
If the reading is within the usable range, check the ECU
for its ground and power supply (see ECU Power Supply
Inspection in the Fuel System (DFI) chapter).
If the ground and power supply are good, replace the ECU
(see ECU Removal/Installation in the Fuel System (DFI)