Civic L4-1668cc 1.7L SOHC MFI (2003)
Fuel Gauge: Description and Operation
How the Circuit Works
The indicators are controlled by relative conditions in their associated systems. For the following indicators the information supplied to the gauge
assembly is received via the multiplex control unit:
-
Charging System
-
Door Indicator Light
-
Maintenance Required Indicator
-
Seat Belt Reminder
-
Trunk Indicator Light
Refer to each associated system to see its entire schematic.
Fuel Gauge and Low Fuel Indicator Light
WARNING: Do not smoke while working on the fuel system. Keep open flame away from the work area. Drain fuel only into an approved
container.
The fuel gauge and low fuel indicator light are controlled by the CPU built-in the gauge assembly. The CPU receives fuel level information from the fuel
gauge sending unit.
The fuel gauge sending unit's resistance varies from about 11 - 13 ohms at full to about 130 - 132 ohms at empty. The fuel level signals current changes
with the varying resistance, which enables the CPU to determine the level of the fuel. When the CPU determines that the fuel level is low, it turns the low
fuel indicator light on. When you turn the ignition switch to LOCK (0), the gauge returns to the bottom of the gauge dial regardless of the fuel level.