The engine controller supplies approximately 5 volts
to the TPS. The TPS output voltage (input signal to the
engine controller) represents the throttle blade posi-
tion. The TPS output voltage to the controller varies
from approximately 0.5 volt at minimum throttle open-
ing (idle) to 4 volts at wide open throttle. Along with
inputs from other sensors, the engine controller uses
the TPS input to determine current engine operating
conditions and adjust fuel injector pulse width and
ignition timing.
VEHICLE DISTANCE (SPEED) SENSOR—ENGINE
CONTROLLER INPUT
The distance sensor (Fig. 14) is located in the trans-
mission extension housing. The sensor input is used by
the engine controller to determine vehicle speed and
distance traveled.
The distance sensor generates 8 pulses per sensor
revolution. These signals are interpreted along with a
closed throttle signal from the throttle position sensor
by the engine controller. The inputs are used to deter-
mine if a closed throttle deceleration or a normal idle
(vehicle stopped) condition exists. Under deceleration
conditions, the engine controller adjusts the AIS motor
to maintain a desired MAP value. Under idle condi-
tions, the engine controller adjusts the AIS motor to
maintain a desired engine speed.
AIR CONDITIONING (A/C) CLUTCH
RELAY—ENGINE CONTROLLER OUTPUT
The engine controller operates the air conditioning
clutch relay ground circuit (Fig. 15). The ignition
switch supplies battery voltage to the solenoid side of
the relay. The A/C fan relay is operated independently
of the engine controller by the Fan Cutout switch.
When the A/C clutch relay energizes, battery voltage
powers the A/C compressor clutch.
With the engine operating and the blower motor
switch in the On position, the engine controller cycles
the air conditioning clutch on and off when the A/C
switch closes. When the engine controller senses low
idle speeds or wide open throttle through the throttle
position sensor, it de-energizes the A/C clutch relay.
The relay contacts open, preventing air conditioning
clutch engagement.
ALTERNATOR FIELD—ENGINE CONTROLLER OUT-
PUT
The engine controller regulates the charging system
voltage within a range of 12.9 to 15.0 volts. Refer to
Group 8A for charging system information.
Fig. 14 Vehicle Distance (Speed) Sensor
Fig. 12 Park Neutral Switch—4-Speed Electronic Au-
tomatic Transaxle
Fig. 13 Throttle Position Sensor
.
FUEL SYSTEM
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