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.
Rear Fog Lamp
The lamps of the rear fog lights are located in the tail lights. The fog lights are operated via a button in the light switch module (LSM). An LED in the button and a symbol in the driver information module (DIM) illuminate when the fog lights are on. The rear fog lights can only be activated when low beam is on (market dependent). The light switch module (LSM) is directly connected to the central electronic module (CEM). Power is supplied to the lamps directly via an output on the central electronic module (CEM).
Upon reactivation of ignition switch position II, the function is set to deactivated mode.
To detect faults in the rear fog lamps, the central electronic module (CEM) reads the power consumption of the circuit. If the power consumption falls below a certain limit, a fault is indicated and a text message is displayed in 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.