Why is my Mercedes ambient lighting not working?
Ambient lighting in a Mercedes-Benz enhances the driving experience by creating a luxurious and visually appealing environment. However, when these lights fail, it can be a source of frustration for the owner. In this case study, we will examine a specific issue with the ambient lighting in the rear right door of a Mercedes E Class W213 and the diagnostic steps taken to resolve it.
Customer Complaint
A Mercedes E Class W213 owner reported that the ambient lights in the rear right door were not functioning. This issue was particularly concerning because the vehicle’s ambient lighting is a key feature that adds to its premium feel.
Vehicle Information
- Model: Mercedes E Class W213
- Issue: Rear right door ambient lights not working
Diagnosis Process
To diagnose the issue, a series of steps were followed:
Initial Test: A quick test was performed, revealing a fault code in the ambient light control unit (N162):
- Fault Code: U109388 “LIN bus 4 has a malfunction. Bus off.”
Wiring Diagram Check: The wiring diagram of the ambient lights in the rear right door was examined. The diagram showed a LIN line for the door control unit, with individual LIN lines for each ambient light in the door.
Visual Inspection: The door panel was removed to inspect the wiring for any visible damage. No damage was found.
Voltage Check: The LIN voltage for the control unit was checked and found to be 0V. The ambient light socket was removed from the door control unit, and the LIN voltage was rechecked, which was then 9V. This indicated a fault in the ambient light wiring harness.
Problem Solving
The next step was to pinpoint the exact cause of the fault within the wiring harness:
- Continuity Check: The continuity of the wiring from the door control unit to the ambient lights was checked, and the values were satisfactory.
- Isolating the Fault: The LIN lines in the faulty harness were cut one by one while monitoring the LIN voltage with a multimeter. After cutting two wires, the voltage rose to 9V. The first wire was reattached, and the voltage remained at 9V. When the second wire was reattached, the voltage dropped back to 0V.
- Identifying the Faulty Light: It was determined that the ambient light for the bottle holder in the door was causing the issue.
Correction
To resolve the issue, the following corrective actions were taken:
- Part Ordered: A rear right door ambient light wiring harness (A2135400571) was ordered.
- Temporary Fix: The faulty ambient light was disconnected, and the new harness was connected to the control unit. The door panel was reassembled.
- Outcome: Disconnecting the faulty ambient light allowed the other ambient lights in the door to function until the new part arrived.
Conclusion
This case study highlights the detailed diagnostic process required to identify and resolve an issue with the ambient light in a Mercedes E Class 213. By methodically checking the wiring and voltage, the technician was able to isolate the faulty component and implement a temporary fix, ensuring the majority of the ambient lights remained operational until the final repair could be completed.
What is Ambient Lighting in Mercedes?
Ambient lighting in Mercedes-Benz vehicles is a feature that enhances the interior atmosphere by providing customizable LED lighting throughout the cabin. This lighting can be adjusted in color and intensity to create a luxurious and comfortable environment, improving the overall driving experience, especially during night-time driving.
How to Change the Ambient Lighting in Mercedes?
Access the Settings:
- Turn on your Mercedes and access the infotainment system.
- Navigate to the main menu.
Find the Ambient Lighting Option:
- Select the “Vehicle” or “Comfort” menu, depending on your model.
- Choose “Ambient Lighting” from the submenu.
Adjust the Color and Brightness:
- Select “Color” to choose from the available options.
- Adjust the “Brightness” using the sliders to set your preferred level.
Save Your Settings:
- Confirm and save your changes.
- Your new ambient lighting settings will now be active.
This process may vary slightly depending on the specific model and year of your Mercedes-Benz. Refer to your vehicle’s owner’s manual for detailed instructions.
How to Check if Your Mercedes Has Ambient Lighting
Check the Infotainment System:
- Start your vehicle and access the infotainment system.
- Navigate to the “Vehicle” or “Comfort” menu.
- Look for an “Ambient Lighting” option. If available, your car is equipped with ambient lighting.
Consult the Owner’s Manual:
- Refer to your vehicle’s owner’s manual.
- Look for information on ambient lighting under the interior features section.
Inspect the Interior:
- Observe the interior of your car, especially around the dashboard, doors, and footwells.
- Look for LED light strips or points that can change color.
VIN Lookup:
- Use your vehicle identification number (VIN) to look up the specifications of your car.
- Visit the Mercedes-Benz website or contact a dealer for a detailed list of features based on your VIN.
Contact a Dealer:
- Contact your local Mercedes-Benz dealership.
- Provide your vehicle’s details and inquire about the ambient lighting feature.
Using these methods, you can determine if your Mercedes is equipped with ambient lighting.