Intake Air Pressure Sensor (Service Code 12)
Pv = Pl – Pg
For example, suppose the following data is obtained:
Pg = 8 cmHg (Vacuum Gauge Reading)
Pl = 70 cmHg (Barometer Reading)
Vv = 3.2 V (Digital Meter Reading)
Pv = 70 – 8 = 62 cmHg (Absolute)
Plot this Pv (62 cmHg) at a point  on the chart and draw a
vertical line through the point. Then, you can get the usable
range  of the sensor output voltage.
Usable range = 3.08 ∼ 3.48 V
Plot Vv (3.2 V) on the vertical line. → Point .
Results: In the chart, Vv is within the usable range and
the sensor is normal.
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
If the ground and power supply are good, replace the ECU
(see ECU Removal/Installation).
FUEL SYSTEM (DFI) 3-47