This guide covers the 12-color ambient-lighting upgrade shown for Mercedes-Benz A-Class 176, B-Class 246, CLA 117 and GLA 156 with NTG 4.5 or NTG 5.0 head units. The kit supports a single color and a 12-color breathing cycle. Programming is required after installation: NTG 4.5 small-screen vehicles use the instrument cluster to control colors; NTG 5.0 large-screen vehicles use the head-unit display.
1. Parts overview
The numbered parts in the original parts image are:
- Front-door light strips.
- Rear-door light strips.
- Dashboard light strip.
- Front footwell lights.
- Rear footwell lights.
- Extension adapter cable.
- Four-door module extension harness.
- Door-control power adapter harness.
- Ambient-light control module.
The parts photograph is labeled for the 2013–2018 A-Class W176 example. Its module label identifies W117/156/176, a 2.4G main module and a 5.0 head unit. These are labels on the photographed hardware; confirm the supplied kit and vehicle configuration match before using its connections or settings.
2. Wiring layout
The layout identifies the control module, vent lights and vent wiring, dashboard light, left and right footwell lights, left and right wiring runs, and the four door-panel lights. The rear-door branches show male/female terminal connections. This image is a layout reference; it does not provide connector terminal numbers or an electrical pinout.
3. Installation
Door installation
Follow the original door-image sequence:
- Remove the chrome door trim, then remove the T30 door screws shown.
- Release the side retaining clip shown in the close-up.
- Remove the chrome door-trim frame, using the illustrated screw and clip locations.
- Replace it with the illuminated door-trim frame and light strip.
- Make sure the retaining clips are fully seated.
- Connect the ambient-light module adapter at the connector labeled No. 3 on the left-front door-control unit in the source image. No. 3 identifies the illustrated connector, rather than terminal 3.
- Join the matching door ambient-light plugs shown.
- Route the rear-door ambient-light wiring through the B-pillar connection shown. For the depicted harness, match the wire colors and fully seat the terminals. This image does not establish a pin assignment for other harness versions.
- Follow the illustrated left-side run connecting the left-front door light, module, footwell light and left-rear door light, with the connection toward the right-side main harness.
- Follow the illustrated right-side run connecting the right-front and right-rear door lights, footwell light and dashboard light strip, with the connection toward the left-side main harness.
Dashboard installation
Follow the original dashboard-image sequence:
- Use a pull hook to remove the air vents. The next photo marks where the hook engages.
- Remove the display screws shown, then remove the display.
- The dashboard trim panel is retained by both screws and clips: the image identifies clips at the left center-vent opening and a screw at the right center-vent opening.
- Remove the illustrated screw and release the panel gradually, working from right to left.
- Install the dashboard LED strip first, with its LEDs facing upward as shown in both the overview and close-up.
- Install the reflective paper in the position shown along the back of the trim. The final two photos show its placement and end detail.
4. Programming and operation
NTG 4.5 small-screen vehicles
Use a Mercedes-Benz diagnostic computer to code the instrument cluster. The source specifies this method for the small-screen configuration; its OBD alternative belongs to the large-screen branch below. After coding, select colors through the instrument cluster.
The two highlighted instrument-cluster entries in the example concern the ambient-light menu and its color menu. The example displays them as present (vorhanden), compared with their original not-present (nicht vorhanden) state. This screenshot is a reference for the illustrated cluster version, rather than a complete coding procedure or a coding string to copy to another vehicle.
Open Settings → Lighting → Ambient Light in the instrument cluster. The source image gives these sequences on the left steering-wheel buttons:
- Single-color breathing: Cool → Neutral → Cool, using Up → Down → Up.
- 12-color breathing cycle: Warm → Neutral → Warm, using Down → Up → Down.
NTG 5.0 large-screen vehicles
The source gives two methods for this configuration: a Mercedes-Benz diagnostic computer or the Cheyisheng (车易升) OBD programming method shown. After coding, select colors through the head-unit display.
The original coding image includes four reference panels:
- Head-unit interface: Ambient Light is shown as on.
- 12-color interface: Color Ambient Light is shown as extended.
- Front SAM ambient-light channel: the highlighted ambient-light enable entry is shown as ja (yes).
- Ambient-light gateway channel: Ambientes Licht vorhanden is shown as verfügbar (available).
These panels show the example controllers and settings. They do not provide a complete procedure for every software version. Some coding strings are obscured by source annotations; do not reconstruct or copy those strings from the pictures.
The historical OBD screen identifies the A/B/CLA/GLA ambient-light function as ID 370 and shows 12 colors, 3 colors and Off, with 12 colors selected. It states that additional hardware must already be installed before this function is used. It also shows a current-status query and an apply-settings control. The picture's sales count and price describe that captured screen; they are not a current purchase instruction or price quotation.
Use the vehicle's main rotary controller on the ambient-light color wheel:
- Change color by turning the controller.
- Single-color breathing: Left → Right → Left, or counterclockwise one detent → clockwise one detent → counterclockwise one detent.
- 12-color breathing cycle: Right → Left → Right, or clockwise one detent → counterclockwise one detent → clockwise one detent.
Main-module DIP-switch reference
The source points to the DIP-switch area on the photographed main module. For the source's 2013–2018 A/B/CLA/GLA 117/176/156/246 reference rows, the four printed columns read from left to right:
| Configuration shown | Printed left-to-right states |
|---|---|
| Small screen | OFF · ON · OFF · ON |
| Large screen | OFF · ON · ON · ON |
The small-screen row also contains a separate pre-2019 GLE/GLS 166/292 label. That shared reference does not extend this tutorial's A/B/CLA/GLA vehicle binding. The chart does not number the four switches or define how its column order maps to every physical module revision; match the actual module and confirmed switch orientation before applying the row.
5. Troubleshooting
- Colors cannot be adjusted: check the coding for the vehicle's configuration and the ambient-light module DIP-switch setting, using the small/large-screen reference above.
- One door has a different color: select red, green and blue in turn to check the three base colors. The source identifies a missing base color as a problem with the light head at that location and calls for replacement.
- One door does not illuminate: check that the ambient-light connector for that door is fully seated.
- All ambient lights are off: check whether the ambient-light output connector from the module is loose and whether the module's adapter connector is fully seated.
- Small-screen vehicle with both ambient lighting and illuminated turbine vents has mismatched colors: run synchronization learning. In the instrument cluster, open Settings → Lighting → Ambient Light → Cool Color. While on the Cool Color screen, press and hold the Up button on the left steering-wheel controls until the ambient lights throughout the vehicle and the illuminated turbine vents flash rapidly. The source identifies that flashing as completion of learning and states that the large-screen configuration synchronizes automatically.