FUEL SYSTEM (DFI) 3-51

Atmospheric Pressure Sensor (Service Code 15)

CAUTION

Never drop the sensor, especially on a hard surface.

Such a shock to the sensor can damage it.

NOTE

○The atmospheric pressure sensor is the same part as the inlet air pressure sensor except that the inlet air pressure sensor has the vacuum hose and different wiring.

Removal•

•Turn the ignition switch off.

•Remove the seat cover (see Frame chapter).

Remove the atmospheric pressure sensor [A] from the

•rubber damper in the frame. Disconnect the sensor connector.

Input Voltage Inspection

NOTE

○Be sure the battery is fully charged.

○The inspection is the same as “Input Voltage Inspection”

•Turn the ignition switch OFF.

•Remove the ECU (see this chapter). Do not disconnect

•the ECU connectors.

Connect a digital voltmeter [A] to the connector [B], with the needle adapter set.

•Special Tool - Needle Adapter Set: 57001–1457

Measure the input voltage with the engine stopped, and

•with the connectors joined.

Turn the ignition switch ON.of the throttle sensor and the inlet air pressure sensor.

Atmospheric Pressure Sensor Input Voltage

Connections to ECU

Meter (+) → BL lead (terminal 1)

Meter (–) → BR/BK lead (terminal 14)

Standard: 4.75 5.25 V DC

If the reading is within the standard range, check the sensor output voltage.

If the reading of input voltage is less than the standard range, remove the ECU and check the wiring between these connections.

If the wiring is good, check the ECU for its ground and power supply (see ECU section).

3-52 FUEL SYSTEM (DFI)

Atmospheric Pressure Sensor (Service Code 15)

Output• Voltage Inspection

Measure the output voltage at the ECU in the same way as input voltage inspection. Note the following.

Digital Meter [A]

ECU Connector [B]

Atmospheric Pressure Sensor Output Voltage Connections to ECU

Meter (+) → G/W lead (terminal 4) Meter (–) → BR/BK lead (terminal 14)

Usable Range: 3.74 ~ 4.26 V DC at the standard atmospheric pressure (101.32 kPa, 76 cmHg abs.)

NOTE

○The output voltage changes according to the local atmospheric pressure.

•Turn the ignition switch OFF.

If the output voltage is within the usable range, check the ECU for its ground, and power supply (see this chapter).

If the output voltage is out of the standard, remove the seat cover and check the wiring. And if the output voltage is 4.8 V, the ECU is normal.

If the wiring is good, check the sensor for various vacuum.

If the output voltage for various vacuum is normal, check the ECU for its ground, and power supply (see ECU section).

○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 vacuum 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.

For example:

Suppose the local altitude is 1300 m (4200 ft) and the sensor output voltage Va is 3.3 V.

Plot this H (1300 m) at a point [1] on the following chart and draw a vertical line through the point. Then, you can get the usable range [2] of the sensor output voltage.

Usable Range = 3.2 3.64 V

Plot Va (3.3 V) on the vertical line → Point [3]

Results: In the chart, Va is within the usable range and the sensor is normal.

3-54 FUEL SYSTEM (DFI)

Crankshaft Sensor (Service Code 21)

Start the engine and switch the diagnosis mode to Dealer 1 mode to know all the problem that the DFI system has at the time of self-diagnosis. If the engine cannot be started, the self-diagnosis system does not detect dynamic condition of the crankshaft sensor. In this case, turn off the ignition switch and turn it on again to enter the Dealer 2 mode. In this mode, the system tells all the troubles which the DFI system had in both static and dynamic conditions.

Crankshaft• Sensor Removal/Installation

See the Ignition System section in the Electrical System chapter.

Crankshaft Sensor Inspection

○The crankshaft sensor has no power source, and when the engine stops, the crankshaft sensor generates no sig-

•nals.

Crank the engine and measure the peak voltage of the crankshaft sensor (see Electrical System chapter) in or-

•der to check the sensor.

Check the wiring for continuity, using the following diagram.

A.ECU

B.Crankshaft Sensor