SL-Class (R230) 2003 -- 2012: Discussion on the SL500, SL550, SL600

SL/R230: MOST loop bypass

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Feb 4, 2023 | 04:43 PM
  #1  
Mikey2274's Avatar
Thread Starter
Junior Member
 
Joined: Jan 2023
Posts: 15
Likes: 0
2006 SL500
MOST loop bypass

So I am getting a little more than frustrated with the issues that I am having getting my new aftermarket head unit to work with my Bose MOST system. 2006 SL500. Audio will work...from time to time. But once I get it to work, and I shut the car off, it will not work when I turn it back on. I verified that the head unit is ok, by running the RCA connectors to my garage stereo. All steering wheel controls and radio functions work properly. I have also verified that the "wake-up" wire at the amp is getting voltage. I ran a jumper wire from the amp remote power wire at the back of the stereo to this wire at the amp harness. Still...only will the stereo work intermittently. The MOST converter has flashing red lights. The other side of the plug also has flashing red lights. I have verified 12+ power/acc. switched and ground at all of the power plugs. I have verified continuity between the MOST converter harness and the RCA plugs. Does anyone have any HELPFUL suggestions?! Should any wake-up/turn on functions need to be hooked up to anything on the CANBUS? Can I run a set of fiber optic cables from the MOST converter directly to the amp? This would bypass the rest of the loop that I really have zero use for...that I am aware of at least. I a;ready hooked up a bypass loop to the cd changer with no change in results. If a direct line to the amp is not feasible, how many...and where...are the additional bypass loop locations? Or should I just buy another converter box off of Amazon so I can return it easily if need be? I am on box 2 as it is.
Reply
Old Feb 4, 2023 | 05:12 PM
  #2  
g0rsq's Avatar
Senior Member
Photogenic
Liked
Loved
Community Favorite
 
Joined: Nov 2021
Posts: 469
Likes: 119
From: North West England
SL500
Originally Posted by Mikey2274
I have also verified that the "wake-up" wire at the amp is getting voltage.
The wake up wire will always be 12V. The "wake-up" signal is a brief (80ms) drop from 12V to 0V then back to 12V

At the same time an optical "wake-up" takes place for 2 seconds.

This optical wakeup needs a reply for the MOST ring to lock.

What is possible is the MOST converter you have is not fully booted up when these wakeup signals are sent, so it sends no confirmation back.

When I install my new head units I leave all the other components in the ring (so I can go back to original).

I would suggest as an experiment is to leave the most converter powered by permanent supply, and see if this clears the issue, which will prove it is a timing issue on the MOST ring.

You may have success by changing the coding for MOST to match removed components, but not the Audio gateway or COMAND
Attached Files
File Type: pdf
MOST system.pdf (3.52 MB, 384 views)
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 06:06 AM.

story-0
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-1
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-2
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-3
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-4
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-5
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-6
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-7
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE
story-8
Mercedes Teases Updated EQS With Steer-By-Wire and a Yoke

Slideshow: The 2027 update adds a fully digital steering system, revised styling, and potential charging upgrades as the company looks to revive interest in the luxury EV.

By Verdad Gallardo | 2026-04-04 10:24:38


VIEW MORE
story-9
8 Mercedes Models With Poor Reliability Records

Slideshow: From problematic air suspensions to early dual-clutch transmission issues, these specific models and years stand out as the least dependable modern Mercedes vehicles.

By Verdad Gallardo | 2026-03-26 18:08:10


VIEW MORE