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 rear fog lights (10/46 and 10/53) are activated by pressing the rear fog light button in the light switch module (LSM) (3/111). The central electronic module (CEM) (4/56) receives a request to activate the rear fog light from the light switch module (LSM) via LIN communication. The central electronic module (CEM) powers the lights directly via an output.
The central electronic module (CEM) transmits information via the Controller area network (CAN) to the driver information module (DIM) (5/1) to light the indicator lamp for the rear fog lamps. The central electronic module (CEM) also lights an LED in the button on the light switch module (LSM) which indicates that the rear fog lamps are activated.
The central electronic module (CEM) measures the power consumption on the output which powers the rear fog lamps. In this way information about lamp status can be obtained. In the event of a fault, the central electronic module (CEM) transmits information via the Control area network (CAN) to the driver information module (DIM) which displays a text message.
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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.
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