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D2B fiber optic bypass loop for Mercedes-Benz
For 1999-2005 Mercedes-Benz with the D2B (Domestic Digital Bus) network. Remove the glove box CD changer or bypass a failed component and keep your radio.
The M&P USA D2B fiber optic bypass loop plugs into the D2B (Domestic Digital Bus) fiber optic connector on 1999-2005 Mercedes-Benz vehicles, so you can bypass or remove the glove box CD changer or a failed module and keep your radio and sound working. It clicks into the factory connector with no cutting or splicing.
Customers most often use it to remove the glove box CD changer and get the storage space back, or to find a bad component. Made in the USA with an OEM-style sealed connection, and backed by our lifetime warranty.
The short answer
- For 1999-2005 Mercedes-Benz with D2B, including the W210 E-Class, W203 C-Class, W220 S-Class, W215 CL, W209 CLK, W163 ML, and early R230 SL.
- Most common use: remove the glove box CD changer, plug in the loop, and the radio keeps working.
- Newer Mercedes or any BMW with MOST? Use our universal fiber optic loop instead. Compare your connector to our photos first.
- Plug and play: no cutting or splicing. More help in our fiber optic bypass loop guide.
On this page
Check your connector before ordering
This D2B fiber optic bypass loop fits the older D2B connectors only. Mercedes switched to the newer MOST fiber optic network starting with the 2003 W211 E-Class. The C-Class and CLK switched during 2005, and the CL and S-Class during 2004 (cars built from September 2003). Compare your connector to our photos. Newer Mercedes and BMW owners need our universal MOST fiber optic loop instead. Not sure? Contact us with your year and model and we’ll help you check.
Before you buy parts, enter your VIN in the NHTSA recall lookup to check for open safety recalls; recall repairs are free at a dealer.
Why one component can kill your radio
D2B is a fiber optic ring: light passes through every infotainment component in a loop. If one component fails or is unplugged, the ring breaks and the whole system can go silent, including the radio and amplifier. Our D2B fiber optic bypass loop closes the ring without that component, so everything else keeps working. This works for the CD changer, Linguatronic, TeleAid, and phone module, not the amplifier or radio, which make the sound.
What’s included
- 1 D2B fiber optic bypass loop with an OEM-style sealed connector that clicks into the factory D2B plug.
Specifications
| Item | Detail |
|---|---|
| Product | D2B fiber optic bypass loop (XM-05QA-8FQD) |
| Network type | D2B (Domestic Digital Bus) fiber optic ring |
| Fits | 1999-2005 Mercedes-Benz with D2B (see the fitment table) |
| Common uses | Glove box CD changer removal; Linguatronic, TeleAid, and phone module bypass or troubleshooting (not the amplifier or radio) |
| Installation | Plug and play, no cutting or splicing |
| Not compatible with | MOST fiber optic systems (newer Mercedes and BMW) |
| Warranty | Lifetime |
| Returns | 30 days |
| Made in | USA |
D2B fiber optic bypass loop fitment
For Mercedes-Benz models equipped with the D2B fiber optic network:
| Model | Chassis | Years |
|---|---|---|
| C-Class | W203 | 2001-2004 (2005: check connector) |
| CL-Class | W215 | 2000-2003 (2004: check connector) |
| CLK | W209 | 2003-2004 (2005: check connector) |
| E-Class | W210 | 1999-2002 |
| ML-Class | W163 | 2001-2005 |
| S-Class | W220 | 2000-2003 (2004: check connector) |
| SL | R230 | 2003-2004 |
| SLK | R170 | 2001-2004 |
Equipment varied by model, year, and region, so always compare your connector to our photos. Have a 1998 E-Class, a 1998-2000 ML, a G-Class, or another model not listed? Contact us before ordering. Newer MOST-equipped Mercedes use our universal fiber optic loop.
How to use the D2B fiber optic bypass loop
- 1Turn the car off. Find the component you want to bypass, such as the glove box CD changer.
- 2Unplug the fiber optic connector from the component.
- 3Plug in the loop. Plug our D2B fiber optic bypass loop into the vehicle-side connector until it clicks into place.
- 4Test. Turn the car on and check the radio and sound. Troubleshooting? Move the loop from component to component until the system comes back; the last one you bypassed is the bad part.
Questions? Contact us and we’ll walk you through it.
Why M&P USA
- OEM-style sealed connection: every D2B fiber optic bypass loop clicks in securely and lasts.
- Lifetime warranty: if it ever fails, we replace it at no charge.
- Made and supported in the USA by a certified veteran-owned business. Questions before or after your order go to a real person through live chat or our contact form.
- 30-day returns: see our Return & Refund Policy.
Frequently asked questions
Can I remove my glove box CD changer with this?
Yes. That’s the most common use. Unplug the CD changer, plug the D2B fiber optic bypass loop into the vehicle-side connector, and remove the changer to get your glove box space back. Your radio keeps working.
Which Mercedes models does it fit?
1999-2005 Mercedes-Benz with D2B, including the E-Class (W210), C-Class (W203), S-Class (W220), CL-Class (W215), CLK (W209), ML-Class (W163, including the ML320), and early SL (R230). Compare your connector to our photos to confirm. G-Class or another model? Contact us before ordering.
What’s the difference between D2B and MOST?
Both are Mercedes fiber optic ring networks. D2B was used on most models from 1999 into the early 2000s, and a few models kept it until 2005; MOST replaced it starting with the 2003 W211 E-Class. The connectors are different, so D2B cars need the D2B fiber optic bypass loop and MOST cars need our universal fiber optic loop.
Is this a D2B fiber optic decoder or coupler?
It’s often searched for that way. This is a D2B fiber optic bypass loop: it plugs into the D2B connector and closes the ring so you can remove or bypass a component.
Why did my radio stop working when I unplugged the CD changer?
D2B is a ring, so unplugging any component breaks it and the system can go silent. Plugging this loop into the open connector closes the ring and restores the radio.
Do I need to cut anything?
No. It clicks into the factory D2B connector, and the connector is sealed. Base-audio cars may have no fiber ring, so check for the fiber cables first.
Not sure which loop you need?
Read the fiber optic guide or send us your year and model, and a real person will help you check your connector.
Mercedes-Benz names are used only to identify compatible vehicles. M&P USA is not affiliated with, endorsed by, or sponsored by Mercedes-Benz Group AG.
Thank you for the great photo review, removing the CD changer is one of the main reasons we designed this product, however, it also works great for diagnosing problem components!