Indicators

The indicator lights are controlled by different conditions set forth in their associated systems. See the associated system for the indicator light circuit description.

LOW FUEL WARNING LIGHT
When there is an adequate amount of fuel in the fuel tank, the resistance of the fuel tank unit is very high and the low fuel warning light will not go on. When the fuel level becomes low, the resistance of the fuel tank decreases, allowing current to flow through the low fuel warning light and the light goes on.

UPSHIFT INDICATOR LIGHT
The upshift indicator light turns on to urge the driver to upshift at the proper moment, allowing operation for the best fuel economy.

The electronic control module (ECM) turns on the upshift indicator light as vehicle conditions become suitable for operation in the next higher gear, and turns off as the clutch is depressed for upshift. The engine parameters used to activate the upshift indicator light are engine speed, engine load and coolant temperature. The engine load is sensed as a function of the throttle position sensor (TPS). The electronic control module (ECM) uses the measured rpm and the vehicle speed to calculate what gear the vehicle is in. It is this calculation that determines when the upshift indicator light should be turned on.

The upshift indicator light turns on when the following conditions exist simultaneously:

1. Engine coolant temperature is hotter than 23°F (~50c).


2. Throttle valve is not in the idle position.

3. The engine load, as sensed by the throttle position sensor (TPS), is not greater than the predetermined values.

4. The transaxle gear is in any forward position other than 5th.

5. The clutch pedal is not depressed.

When the light switch is in the HEAD or PARK position, the light switch provides battery voltage to the upshift indicator relay. The upshift indicator relay energizes and puts a resistance in series with the upshift indicator light. This provides the dimming function for the upshift indicator light.