Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Brake warning lamp
The brake control module (4/16) (called ABS module on model years up to and including 2001) informs the driver information module (5/1) via the Control area network (CAN) if there is a fault in the brake system. The driver information module indicates this to the driver by lighting the red general warning lamp and displaying a text message.
The brake fluid level sensor detects the level of the brake fluid in the reservoir. When the level is low, a switch in the sensor closes and the warning lamp lights. This function is directly connected to the driver information module.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.