3-50 FUEL SYSTEM (DFI)
Inlet Air Pressure Sensor (Service Code 12)
Remove the inlet air pressure sensor [A] and disconnect
the vacuum hose from the sensor.
Do not disconnect the sensor connector.
Connect an auxiliary hose [B] to the inlet air pressure sen-
Temporarily install the inlet air pressure sensor.
Connect a commercially available digital meter [C], vac-
uum gauge [D], and the fork oil level gauge [E] to the inlet
air pressure sensor.
Special Tools - Fork Oil Level Gauge: 57001-1290
Sensor Harness Adapter: 57001-1561
Inlet Air Pressure Sensor Output Voltage Connection to
Meter (+) → Y/BL lead
Meter (–) → BR/BK lead
Turn the ignition switch ON.
Measure the inlet air pressure sensor output voltage from
various vacuum readings, while pulling the handle of the
fork oil level gauge.
Check the inlet air pressure sensor output voltage, using
the following formula and chart.
Pg: Vacuum Pressure (gauge) of Throttle Assy
Pl: Local Atmospheric Pressure (absolute) measured by
Pv: Vacuum Pressure (absolute) of Throttle Assy
Vv: Sensor Output Voltage (V)
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 volt meter reading)
Pv = 70 – 8 = 62 cmHg (abs.)
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.