Brake Warning Indicator

The brake warning indicator receives its ground signals from the following sources:

• The parking brake switch provides a ground when the parking brake is depressed.
• The dual brake warning switch provides a ground when there is low brake pressure.
• The anti-lock brake system (ABS) control module provides a ground when it senses an ABS system malfunction.
• The low vacuum switch (diesel only) senses low engine vacuum and provides a ground.

The ignition switch provides the brake warning indicator prove-out by supplying a ground when it is in the START position.