Spectrum L4-91.5 1.5L (1989)
Shift Indicator: Description and Operation
The shift indicator light is a device which is installed in the instrument panel to urge the driver to up shift at the proper moment. This insures operation
for best fuel economy.
OPERATION
It turns on as soon as vehicle conditions become suitable for operation in the next higher gear, and turns "OFF" as the clutch is released for up shift. The
engine parameters used to activate the shift indicator light are engine speed, engine load and coolant temperature. The engine load is sensed as a function
of throttle valve position by a sensor (Throttle Position Sensor) built into the carburetor. The shift indicator light turns on when the following conditions
exist simultaneously:
1.
Engine coolant temperature is hotter than 5°C.
2.
Throttle valve is not in idle position.
3.
The engine load, as sensed by the throttle position sensor, is not greater than the predetermined values.
4.
The transaxle gear is in any forward position other than 5th, that is, either of the two transaxle switches (1st-2nd switch and 3rd-4th switch) is
"ON." 1st-2nd switch turns "ON" when the transaxle is in 1st or 2nd, and 3rd-4th switch turns "ON" when the transaxle is in 3rd or 4th.
5.
The clutch is engaged (clutch switch is "ON"). The control system schematic is shown in CHART C-8A.
