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 fluid level switch
A low brake fluid level is picked up (in the expansion tank via a reed contact) and notified to the DSC control unit. With a low brake fluid level, DSC is disabled. Otherwise, there is a danger that air will be drawn into the brake system.
| Index | Explanation |
|---|---|
| 1 | Sealing cap with brake fluid level switch |
| 2 | Brake fluid expansion tank |
| 3 | two-pin plug connection |
The brake fluid level switch is activated in response to a low fluid level in the brake fluid reservoir. The DSC control unit sends the signal of the bus system to the instrument panel. The instrument panel issues a Check Control message. The usual motion of the brake fluid within the reservoir does not generally trigger a Check Control message.
There is a permanent magnet in the moving float; this triggers the reed contact in the brake fluid level switch firmly fitted in the fuel tank. Here, the reed contact converts the float movement into an electrical signal. The reed contact is closed while the brake fluid level is above the minimum mark.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.