SRS light during stereo installation

[cyberflex]

Hi cplnoonoo, come to that, hi everyone, this is my first post, I always said that if I could offer any help to a fellow forum member I would post, so here goes.
After having read various threads on the forum I successfully installed a Kenwood KDC-BT8044U head unit using the connects 2 'CT24MB01' single DIN fascia adaptor, I preferred this fascia adaptor as it came with the cubby hole tray, which helps to maintain 'as stock a look as possible' when removing the audio 10 and replacing it with any aftermarket single DIN unit, also, imo, the overall fit is a huge amount better than some of the other W203 fascia adaptors I have seen in various forums whilst researching.
If you did not have factory comand in the first place you will need 2 extra MB pan head screws in order to secure this fascia adaptor and feel confident it is held in place as securely as possible, available from any MB dealer,£2.50 each. I bought 4 fresh ones as the new ones seem to have a machined washer aswell.
cplnoonoo, I have a September 2001, W203 C320 avantgarde, which had the Audio 10 tape player and factory cd changer in the glove box, the car has been with us from new.
When I removed the audio 10 head unit I also found it used two 8 pin iso connectors for power and speakers and one 10 pin iso connector that contained 5 active allocated pins which were CAN High, CAN Low, cd changer +12v, cd changer wake up and I guess cd changer ground. I remember reading your 10 pin iso only had 2 wires/pins,CAN High and CAN Low, which would make complete sense if you did not have the factory cd changer.
I was just interested in the CAN High and CAN Low from this plug, as I was removing the cd changer and d2b fibre optic cable from the glovebox area. Also just for information I should mention I also pulled the 3 pin molex type connector through from the glovebox to the centre console area where it was insulated,cable tied and tucked away for possible future use.
OK, back on topic, I too searched high and low for the Kenwood CAW- MB1110 steering adaptor but was told it had been replaced with the new universal range with various individual harnesses to suit a particular car.
I still believe Kenwood has overlooked a solution for all Mercedes with CAN BUS contained in a 10 way iso connector, i.e. all those with pre-facelift w203's,(maybe more), anyway I chose not to take the risk of using the ones from the new range as I was not convinced any of them were 10 way iso and moreover that the new modules had been tested for use in the pre-facelifted w203's by Kenwood. I did not want to remove the 10 way iso and connect the CAN High and CAN Low with another companies adaptor as I want to keep my cars audio related wiring as stock as possible until these adaptors are really proven to be stable in our cars. So I just insulated that plug and cable-tied it out of the way.
The person I spoke to at Kenwood UK technical said she could order one but there would be no refund. I was just convinced I would get something for the later W203 cars and did not want the grief.
Also as fellow user 'omega1' had success with the CAW- MB1110, as far as I was concerned it was that or nothing for my particular scenario.
Thus, I thought it best to forget about the steering wheel controls for the time being until there was a definite substitute that worked with the pre-facelift cars, also with the Kenwood CAW-MB1110 steering wheel interface, I guess that is all that it would have been, just the steering wheel controls not a full CAN BUS conversion (in terms of aftermarket head units) that would generate +12v ignition, illumination, speed pulse, reverse signal e.t.c. which I guess was the reason for their new range.
So, I opted to just take a feed for +12v ignition and a seperate feed for illumination from the feeds going to the cigarette lighter as these were the only feeds missing that the KDC-BT8044U needed.
Also after searching the web for a long period of time I also felt after much internal debate, that being as the pre-facelift w203's seem to have so many issues with the CAN BUS being kept awake leading to battery drain issues from various rogue modules that are factory installed, (which btw I had experienced first hand some months before my install, yes guys and gals, the dreaded seat modules on drivers and passengers sides) I felt uneasy using the CAN BUS in my vehicle with an aftermarket adaptor, just incase it kept everything on the network active which would lead to more battery drain issues. No thanks.
I guess if I had a facelifted W203 or even a W204 and wanted to go aftermarket in terms of audio, I would not really hesitate as these cars seem electronically more evolved/stable from the reading I have done.
I know from reading your earlier posts in the past, you have seen the SRS visit workshop warning before, I too saw the warning when I had my centre console disconnected and turned the key to position 1, infact I saw this warning a number of times during the days it took me to carefully finish the install. However, I only ever turned the key to position 1 to check the ignition live I had created with a multimeter, I never went to postion 2 or a crank for fear of logging a more permanent fault.
To be honest, I was scared when I first saw the message but after reading various bits on the forums including 1 thread that you yourself contributed to last year, I was made to feel alot better when the general concensus was, that when the console was reconnected and the car was driven for a while, it would disappear, this was the case for me and I have not seen the message again in the 5 weeks since the install was completed.
I know you probably thought of this, since you have taken your console out a few times by now I guess, but maybe check that the molex type connector is plugged into the very furthest socket to the right when facing the console in situ, as on the back of my switch panel there were 2 identical sockets, not sure if this would make a difference or not.
Also I remember reading something on one of the US forums that someone got various warning messages and malfunctions when using a CAN BUS adaptor to generate aftermarket audio related signals with an early W203 C class.
The only one I know that works well in terms of Kenwood for the prefacelift w203's seems to be the CAW-MB1110, as omega1 seems to have had no issues at all.
I would suggest before going to one of the tech's with star or something else, you should firstly double check everything then drive around a bit with the CAN BUS interface in place, if the warning does not go away try disconnecting the interface from the 10 way iso plug, drive around a bit and see if the error goes away.
If you have used something other than the Kenwood CAW-MB1110, and the firmware within it is not compatible with the earlier W203's bus protocols I am pretty sure I have read that the symptoms you have are not uncommon.
Sorry for the long post guys and gals, the information that cplnoonoo, omega1 and alot of others on this forum helped me complete my install without snapping a single thing and I just felt it necessary to go into detail so that maybe I could give something back to people who use the search function like I did, in the future.
Hope you get it sorted fella, also thanks again to anyone who has contributed to anything w203 audio related in this forum, I would have snapped alot of things without you
Jon.

[cplnoonoo]

Well i managed to get a MB1110 free from kenwood to try and see if that worked and i didnt manage to get it going. That was a few months ago and i just left it connected even though it wasnt working and no harm was done.

On sunday night i had to check the underside of the car for gearbox oil (you can see my post about this in the engine section) so i thought why not have a look at the other problems ive got while im at it.

So i fixed my ashtry which i had jammed as a result of dropping the 2 screws from the bottom of the console brackets and attempted to troubleshoot the interface problem. I have about 4 different interfaces for various different merc models as kenwood kept sending me different ones to see what i could get to work as i had a big arguement with the head of their tech dept and they wanted to see what could be made to fit the c class with the isos.

I think i managed to find that the old MB1110 had a too big an adapter on the 10way iso which meant that the pins didnt completely connect. I eventually tried to adapt the new harness for the a class which is the only one they advertise at the moment for mercs with iso connections.

This post http://www.mbclub.co.uk/forums/883985-post12.html shows the connector from the old interface (on the left) connecting to the cars 10way iso plug (on the right). I have cut off the plastic connector from the left leads and used the metal flat pins to solder the green cables (seen here on the left of the pic just above the black block http://www.kenwood-electronics.co.uk...c/CAW-CCANME3/. I then plugged these into the plug that was seen on the right of the first link above.

I had to connect the 2 white and green wires for the canbus and then cut the tiny plastic connector off the end and solder these onto the slotted pins that i removed from the old interface model. I manually pushed these into the 10way iso plug coming from the car and managed to get it working but due to the amount of wiring that the new harnesses have it was a bit of a struggle to get it all to fit behind the stereo without blocking the fan etc.

I think whilst i was pushing everything back in that i must have dislodged a couple of wires as i couldnt get it working when all was back in place. I then checked various connections and realised that when the green wire was connected on its own the buttons all worked but when i pressed the menu up/down buttons (the arrows) on the left of the steering wheel it changed the display of the instrument cluster (as it should) but it also sent the radio scanning up or down a frequency in whichever way the arrow was pressed. The interface only worked when the ignition was on as i noticed that as soon at the key was out and the instrument cluster display turned off the buttons no longer worked.

So when i connected the second wire (the white one) none of the buttons worked. They both worked before i pushed everything back in so i thought maybe there was another connection i had missed. Couldnt find anything so went to push the white wire back into the corresponding slot on the 10way iso and thats where i got my problem.

As i was doing this the blue light on the dash to indicate full beams came on whenever i touched the wire on the terminal and after touching it a third time the roof light went out and the srs light message came on. At this point i thought ****(i put the stars in here lol) and disconnected the interface from the equation altogether and connected the stereo back up without any interface.

Thats when i posted on here to try and solve the srs light problem.

A couple of posts back someone mentioned that i can clear the srs using a standard code reader - will an OBDII code reader do this fine or is star definitely needed? I have access to an OBDII reader but it is at my friends garage.

Is it worth trying this or will it definitely not work?

Sorry for this long post btw lol.

[Baron_Samedi]

I think that if the ODB reader has the option to reset SRS codes you should be fine.

[cplnoonoo]

Do most of these readers have that ability?

[Baron_Samedi]

Check the adverts carefully to be sure - I find the ones with the ability cost around £60.

I found it easier and cheaper to sweet local my local garage into using their kit.

[cplnoonoo]

My friend already has one but his garage is on the extreme outskirts of dundee so only going to go up there if know it will definitely work.

[cyberflex]

Hi cplnoonoo, I really feel for you dude, I really do.
I think I need to really see what has been done to really understand what has gone wrong. I know this is impossible and I am no expert in any case, so I suggest the following:-
I know this is probably going to be a pain but from the things you have written I am worried that you have possibly fried a module/s in the worst case or hopefully just logged some diagnostic trouble codes in the best case.
Please understand I am not trying to be clever with you, I just want to try to help.
I think that you should remove the upper vents, ashtray, centre console e.t.c. in order to pull your headunit out again.
Once you have all 3 iso connectors in sight, concentrate on the 10 way iso containing the twisted pair of canbus wires, they are brown if I remember correctly. Just make sure these are not shorting on anything, infact, if you have removed the original 10 way iso in order to try out some other Kenwood modules just make sure you locate the 2 brown canbus wires and insulate them individually, well, and just tuck them out of the way.
I am going to be buying a CAW- MB1110 soon from Germany and will inform you how I get on with it. It just seems strange that omega1 had no issues at all.
For the time being just use the 8 way iso for speakers and the other 8 way iso for the power that was originally connected to the audio 10.. I need to ask you something, as I stated I did not want the hassle of the canbus generated signals so did not touch my 10 way iso at all, just taped it up and tucked it away until I find a solution that works with our cars canbus. How did you get ignition live, illumination and I guess in your case speed pulse and reverse signal?? I know you have satnav?
As you know I installed a KDC-BT8044U and the Mercedes 8 way power ISO did not have ignition live and illumination, so I just tapped the feeds to the cigarette lighter to create these for my head unit, instead of generating them via Canbus.
Once you are sure your brown twisted pair of Canbus wires are not shorting on anything, just insulate them individually as stated above or if they are still intact within the original 10 way iso, insulate this 10 way iso, tuck it safely out of harms way and put everything carefully back.
I am pretty sure any decent diagnostic tool can access the SRS module and other modules if necessary and clear out the diagnostic trouble codes. If they do not clear or they reappear I think you have to go to one of the tech's on here, who will run a short test with star and find out which modules are (I hate to say it) fried. That is the the thing I was most scared of, those 2 canbus wires should be treated with the utmost respect as they are in constant communication with everything. I did not dare even put a multimeter near either of them as they are part of the vehicles controller area network which I do not fully understand. I think there is special canbus testing equipment that alarm installers/taxi meter installers use to locate can high and can low for convenience stuff like locking, windows, indicators, speed pulse e.t.c. also I believe the engine has its own canbus aswell. They may appear like 2 normal wires that can be treated normally when looking at them, but from the reading i have done they are anything but. Best left alone.
However, I should state that hopefully all I think has happened is the canbus adaptor you tried out was not firmware compatible and thus generated some DTC's and these can be cleared easily.
I hope all goes well, please just pull everything out and make sure the 10 way iso or the 2 brown wires that went into the 10 way iso are not shorting on anything or on eachother, just leave them alone for the moment. Take the car somewhere and try to clear the codes. If it is a no go, go and visit one of the techs on here with star.
When I get hold of a CAW-MB1110 or something equivalent and it works I will let you know, I will also let you know exactly how I got it to work, if I am successful.
cplnoonoo your previous posts helped me and I really want to help you if I can mate. Just please leave the cars canbus alone for the time being, i.e forget about the steering wheel interface until we get more info.
All the best mate. Jon.

[cplnoonoo]

I have the DDX8024BT and had the problem of getting the ignition feeds etc. You have to change the bullet connectors on the yellow and red cables on the stereos harness so both the red and the yellow cables on the stereo harness feed into the one live feed from the cars harness.

The ignition feed is not easily possible (ie to get the stereo only turning on when the key is in as it is an electronic ignition and difficult to wire it up). So you have to do as i said and have both yellow and red connecting to the cars single power feed on the harness. The power feed on the cars end of the harness is in the right place to match one of the stereos power connections so you dont need to rewire that at all. Just change the stereos harness using the bullet connectors (you may need to put a new one on the stereos side) so that they both feed onto the cars power lead.

As for illumination you can try and change the location of the illumination lead on the stereos iso connector so that it matches the cars feed for this but i havent bothered as its not a hassle for me to just change the dimness manually through the menus (its a touch screen anyway) whenever i drive in the dark and change to day etc.

The stereo is fine and everything is working fine so essentially i dont have an issue any of the stereo etc apart from the interface which i will deal with separetely. The stereo is all connected up without and interface and the only outstanding issue at the moment is the srs light and message being displayed. The srs message on the screen comes up everytime i start the engine but goes away when i press any of the menu buttons. The red srs light along the bottom of the cluster (opposite side from the parking brake light) does stay on all the time but its not a problem...its easy enough to ignore until i get the error code cleared.

As for frying any of the components etc i am pretty sure all is ok as i didnt set off any of the airbags and everything that was electrically powered worked fine instantly after it had turned off. It drives fine no problems at all and no other electrical issues so im quite confident that all i need is to clear the error code and that there isnt actually any error present...there is just the message and light as i had the ignition on at the same time as i was doing the rewiring as i needed to get the car out of park etc. long story short (kind of) it was my fault anyway really as i had the ignition on as i was doing the wiring. I kinda had to as the interface needed the power feed to allow the buttons to work the stereo and as my problem was trying to get the buttons to work i had to keep checking they were functioning by keeping the power on.

I will probably get the fault code cleared by the weekend i think and then i will try and have another shot at getting the interface to work.

At the moment iv got a few other things more important than getting the interface working so im not in much of a hurry.

Btw i reckon the reason the old interface wasnt working was that the 10way iso plug on the kenwoods end wasnt allowing the 2 pins to make a decent connection for the buttons to work.

I shall post back when i decide to get the interface fitted.

[cyberflex]

Hi. I now understand a bit more about your situation and can offer the following:-
Whenever I looked at my audio 10 tape player, I always thought it looked out of date, even back in 2001 when our car was new, back then there were no fascia adaptors and the dealer we got our car from told me that everything was fibre optic and no aftermarket solution would ever be viable, I remember thinking back then, that this was rubbish,I fully understand that the cd changer, audio 10/comand, bose amplifier use D2B in earlier cars and MOST in later cars to communicate via a fibre optic ring, but if your car has no bose system and you are removing the audio10/comand and cd changer there will be no issue whatsoever.
The only clever thing about the audio 10 is it has a built in canbus module(via 10 way iso) that allows it to generate its own ignition signal(so it goes off when you turn the the key and remove it). Also it generates its illumination/dimming signal in the same method. The comand units generate speed pulse via inbuilt canbus aswell. Both communicate via canbus with the steering controls aswell.
All the American lot who use the pioneer double din units and the very difficult to find 'car pi 131' steering wheel canbus adaptor complain about the fact that their units do not dim at night and also do not switch off when when they turn off the ignition with the key.
The solution to this which I found via searching their forum, that they now ALL use, is to create their own ignition and illumination +12V's.
I followed their method and I can say it 100% worked for me as it has for every single one of them.There is no need to go playing with EIS (The cars electronic ignition system) to get the ignition +12v feed.
In your centre armrest is the cigarette lighter, if you remove your gearshift surround and trace the wires back that feed the cigarette lighter you will notice there will be 3 wires that are loomed up together
These are :-
1) BROWN - GROUND
2)A thinner BLUE/GREY- ILLUMINATION +12V
3) BLACK/YELLOW- IGNITION +12V
I double checked these went into the cigarette lighter by removing the cupholder and folding the cigarette lighter towards the rear of the car, this bit is very tricky and is not really necessary now as these 3 wires have been used by so many people and are the only ones going to the centre armrest area.
I triple checked the above cigarette lighter feeds with my multimeter whilst switching the ignition on and off and the lights on and off to make 100% sure they were doing what the forum members said they would do, Kudos to the US guys, they were spot on.
All you have to do to get ignition is to tap into the BLACK/YELLOW wire using good quality cable from maplin or somewhere, and connect this new cable to the red wire from your DDX8024BT, leave the yellow wire intact in the existing iso for the permanent/memory feed to your DDX8024BT.
You have to do the same as above to the thinner BLUE/GREY wire using again good quality cable and this time connect it to the ORANGE/WHITE wire from your DDX8024BT.
These wires will ground from the existing ground you have going to your DDX8024BT, so no need to tap the brown ground cigarette lighter wire.
You could inline fuse these taps, but I did not, just made sure I soldered and heat shrunk slowly to produce quality taps and left the existing fuses in the SAM's to protect.
HEY PRESTO, you will have the ability of your DDX8024BT turning off when you turn the car off and also the buttons around the DDX8024BT's screen dimming when your headlights are on at night.
I also understand fully (because your posts are concise) why your Kenwood CAW-MB1110 might not have worked now. I am not 100% sure yet as I do not have it yet but from reading how Omega1 did his, and trusting his work as I used his incredible thread to help me, I am almost 100%
The CAW-MB1110 has 5 connections that need to made,
1)The female 10 way iso from the CAW-MB1110 plugs into the Mercedes 10 way iso.
2) The blue connection from the CAW-MB1110 plugs into the blue remote lead from the DDX8024BT.
3)The red connection from the CAW-MB1110 plugs into your newly formed ignition lead from the cigarette lighter that now will be going to your red wire from the DDX8024BT aswell. (3 way splice - newly formed igntion wire goes to red wire from DDX8024BT and red wire from CAW-MB1110.
4)The black wire from the CAW-MB1110 taps into the black wire from the ground connection to the DDX8024BT.( Black wire from 8 way female kenwood iso carries on going to black wire to DDX8024BT but is also spliced to go to black wire from CAW-MB1110 aswell).
5)Finally the roundish din type connector from the CAW-MB1110 goes into the back of your DDX8024BT.
I understand this is not a priority at the moment but please give it a good going over with the above instructions next time you have your unit out again.
Also make sure that the 2 brown wires in the Mercedes 10 way male iso still correspond with the 2 grey wires from the CAW-MB1110 as you have said you have tried it with other adaptors aswell.
The above info has worked for me and many others around the world but if anybody reading this is unsure in the slightest, please take your car to an audio place or auto electrician, I have been into car audio since I was about 15, I am 32 now.
I take no responsibility for anybody mucking their car up.
If my mum planned to keep the c320 I would have definately gone double din, and in retrospect paid more for Alpine as I remember many years ago seeing someone with an Alpine headunit in a W203 c class that had full steering wheel control aswell as displaying its info on the instrument cluster aswell. Not sure if they still produce this adaptor for the w203 c class though, also she is moving to a w204 c class some time in the near future as she feels 8 years odd is enough,(problems starting to appear) Alpine stuff is more expensive, their Bluetooth module is separate e.t.c. But it really is quality from my experience.
Hope the above helps anybody interested.
Jon

[cplnoonoo]

I think im happy enough with my power feeds as they are ie the stereo works with ignition on or not and i just manually power the stereo on/off myself. Also means that i can leave my stereo on whilst having the car locked with keys in my pocket whilst im washing car etc as it was a pain before on my old car to keep having to remove keys and having the stereo turn off every time i wanted to go round the back of the house and leave the car on the pavement etc. Now i can leave the stereo on but have the car locked if im only leaving it for a minute.

Not really wanting to mess about with the cigarette lighter etc as i said above so only need to get codes cleared.

As for you getting a hold of the old interface - not going to happen buddy. Unless you can find someone selling on ebay or something your gonna have to find a solution to using the new version interfaces.

Headunit-wise - i would recommend the ddx8024bt anyday. It has built in parrot bluetooth and comes with a separate tiny microphone that you can put on a pillar to the right of the sun visor behind the interior trim and the audio quality is perfect. You can set it for radio/cd in the front speakers whilst having a completely different audio track in the rear (dvd etc). You can even have your own wallpaper on it (mines is the mclaren of lewis hamilton at the moment) and a full graphic equaliser.

It is a tad expensive...i paid £850 including interface and fascia plate.

Also on a final note - getting audio specialists arent always the best option as some of the guys near me wouldnt touch it as a bit of rewiring was required and they didnt want the hassle of possibly messing the electrics up. They just settle for a simple plug in, fit into dash and take you money. Im sure there is other decent franchises out there that will do the full job but obviously what you pay for the service you get.