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Trip Computer: Description and Operation

TRIP COMPUTER





Description

When the ignition is switched ON, the LCD back lights illuminate and the trip computer defaults to the time of day. The time button is dual function; first press gives the time of day, a subsequent press causes the elapsed time since reset to be displayed, with leading zero suppressed. After five seconds the elapsed time reverts to the time of day.

The trip computer provides information on vehicle speed, fuel usage and distance travelled, all of which are calculated by a microprocessor. It computes fuel consumption, both average and 'at the moment' usage, fuel used on a journey or period; distance travelled, average speed and time elapsed since the start of the journey or over a period. The information may be displayed in either litres and kilometers or in miles and gallons.

The unit also provides a warning of fuel failure. In the event of an engine management fault occurring, the 'check engine' warning light and the words 'check engine' are permanently displayed on the trip computer until the engine is switched off. When the fault has been signalled, the likely area of malfunction can be indicated when the vehicle is stationary. Switch off the engine, wait at least five seconds, turn the ignition switch to position II (do not start the engine). The relevant failure code FF11 to FF99 is displayed.

With reference to figure, inputs 7, 8 and 9 have a maximum low of 1.2 V and a minimum high of 7.5 V and is supplied directly from the side light relay.