Operation CHARM: Car repair manuals for everyone.

System Description For Meters and Gauges

UNIFIED CONTROL METER
^ Speedometer, odo/trip meter, tachometer, fuel gauge and water temperature gauge are controlled totally by control unit combined with speedometer.
^ Digital meter is adopted for odo/trip meter.*
* The record of the odo meter is kept even if the battery cable is disconnected. The record of the trip meter is erased when the battery cable is disconnected.
^ Odo/trip meter segment can be checked in diagnosis mode.
^ Meter/gauge can be checked in diagnosis mode.


HOW TO CHANGE THE DISPLAY FOR ODO/TRIP METER





NOTE: Turn ignition switch to the "ON" position to operate odo/trip meter.

POWER SUPPLY AND GROUND CIRCUIT
With the ignition switch in the ON or START position, power is supplied:
^ through 10 A fuse [No. [11], located in the fuse block (J/B)]
^ to combination meter terminal (29).

Ground is supplied:
^ to combination meter terminal (26)
^ through body grounds (M14) and (M68).

FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by a variable ground signal supplied:
^ to combination meter terminal (7) for the fuel gauge
^ from terminal (G) of the fuel tank gauge unit
^ through terminal (E) of the fuel tank gauge unit and
^ through body grounds (M14) and (M68).

WATER TEMPERATURE GAUGE
The water temperature gauge indicates the engine coolant temperature. The reading on the gauge is based on the resistance of the thermal transmitter.
As the temperature of the coolant increases, the resistance of the thermal transmitter decreases. A variable ground is supplied to terminal (6) of the combination meter for the water temperature gauge. The needle on the gauge moves from "C" to "H".

TACHOMETER
The tachometer indicates engine speed in revolutions per minute (rpm).
The tachometer is regulated by a signal:
^ from terminal (3) of the ECM
^ to combination meter terminal (9) for the tachometer.

SPEEDOMETER
The vehicle speed sensor provides a voltage signal to the combination meter for the speedometer.
The voltage is supplied:
^ to combination meter terminals (8) and (10) for the speedometer
^ from terminals (2) and (1) of the vehicle speed sensor.

The speedometer converts the voltage into the vehicle speed displayed.