Engine Electrical Devices: 1C-4
Throttle Position Sensor (TPS)
Three sensors (MAP sensor / TPS / IAT sensor) are
combined into one unit that is installed on top of the
throttle body.
The TPS detects an angle of the throttle opening.
The TPS is non contact type sensor using a hall element
and it converts the throttle valve opening into a voltage
signal which is then inputted into the ECM.
Based on the TPS voltage, the ECM calculates the
throttle position to determine the appropriate modes to
the various controls systems (idle air control system, fuel
injection control system, etc.).
Neutral Switch
The neutral switch is installed on the clutch lever holder
and is used to detect the shift position.
This switch is “ON” in neutral and “OFF” in forward or
reverse.
The ECM performs the following control based on the
neutral switch signal:
• When the shift lever is in neutral, fuel injection is
controlled to prevent engine speed from exceeding 3
000 r/min.
• After shifting into forward or reverse from neutral, the
IAC valve is controlled to increase intake air to
prevent unstable engine idle or stalling.
• When the shift lever is in forward or reverse at the
time of engine start, the ECM will not supply power to
the starter motor relay, thus preventing starter motor
engagement.
(Start-in-gear protection. Refer to “Start-In-Gear
Protection System Description” in Section 1I (Page 1I-
2).)
Trim Sensor
The trim sensor is variable resistor type.
With the sensor signal received, the ECM performs the
learning of the trim/tilt position and it controls the position
of both the trim down limit and the tilt up limit.
The trim sensor signal also operates the trim meter
through the ECM.
1. TPS
1
1. Neutral switch
1. Trim sensor
1
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