Instrument Panel, Gauges and Warning Indicators: Description and Operation

CIRCUIT DESCRIPTION

The operation of individual indicators is stated below. For indicators not listed below (for instance, door ajar, seat belt, etc...), see the system indicated by the circuit schematic diagrams.

Oil Pressure indicator

Battery voltage is applied to the indicator bulb from fuse 18 with the ignition in ON or START. When the oil pressure is low, the oil pressure switch closes, providing a ground for the indicator bulb. Due to the oil pressure not present when the engine is not running, and the ignition is ON, the pressure switch remains closed.

CHECK ENGINE Indicator

Battery voltage is applied to the indicator bulb from fuse 18 with the ignition in ON or START. The ground of the indicator is controlled by the engine control module. The control module will light the indicator when the engine is not running or when it detects a problem.

Parking Brake

With the ignition switch in ON or START, battery voltage is applied from fuse 18 to the brake warning light. When the brake is applied, the switch closes and provides a ground for the light. The brake warning light goes on to remind the driver that the parking brake is applied.

Brake Fluid Level

With the ignition switch in ON or START, battery voltage is applied from fuse 18 to the brake warning light. If the brake fluid level is low, the brake fluid level switch closes and ground is provided to the circuit. The brake warning light lights to warn the driver of low brake fluid leveling the brake master cylinder. (Note : Check brake pad wear before adding fluid.)