ABS Light: Description and Operation

Circuit G5 provides power for the Anti-Lock Brake System (ABS) warning lamp at the instrument cluster. Ground for the ABS warning lamp is provided by either the ABS control module or by the ABS power relay when the relay is not energized. The ABS control module illuminates the lamp by providing ground on circuit G19.

Circuit G19 splices to connect to circuit B15 through a diode. When the ABS power relay is not energized, it connects circuit B15 to circuit Z12. The ground path for the warning lamp is provided through the diode to circuit B15, through the ABS power relay to ground on circuit Z12.

The diode between circuit G19 and B15 prevents voltage from flowing to the ABS control module when the ABS power relay switches to supply power on circuit B15.