Without Daytime Running Lights

The brake warning indicator illuminates when the when one or more of the following occurs:

• The Electronic Brake Control Module (EBCM) performs the bulb check. The EBCM applies ground to the Anti-Lock Brake System (ABS) pressure differential sensor signal circuit.
• The brake pressure differential switch is closed by a pressure differential between the front and rear brake circuits. The brake pressure differential switch applies ground to the ABS pressure differential sensor signal circuit.
• The park brake is engaged. The park brake warning switch applies ground to the brake warning indicator control circuit.