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Here's a way of keeping your steering wheel controls with an aftermarket stereo !

70K views 57 replies 13 participants last post by  amgdvl  
#1 ·
I recently bought an excellent Sony MEX BT 3500 head unit for a great price at Halfords only £127 ! as I got a discount by reserving on line. The sound much sharper, louder and fuller then the stock CD as well as having a whole host of features that the stock stereo did not have, which is the reason I bought it.
For example I now have USB front input, ipod, Aux input, mp3, wma, etc etc compatibility as well as an excellent Bluetooth handsfree feature with built in mic so I dont need to ever touch my phone whilst driving, it just stays in my pocket ! and it also does Bluetooth music streaming to play your tunes too !

Now I knew that when I installed the Sony I would lose the ability of the steering wheel buttons, but not now I have added a PAC steering wheel adaptor controller. I live in the UK and had to order it from the US but it still only cost me about $110 all in !

For my CLK 2000 year model I needed to by two different adaptors and plug them together, one does the CAN BUS conversion (PAC SWI-CAN2) and the other is a general steering wheel adaptor (PAC SWI-PS) and the PAC customer services were really helpfull. Authorized dealer info

I wired it up and programmed it pretty easily and theres an online video to help too, in total it took me about 2 hrs to do. Steering Wheel Interface Training Video
And now I have full control again of my volume up and down steering wheel buttons and the left track up and down buttons too just like before!!
 

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Discussion starter · #3 ·
This is an idiom so it may not translate well to your side of the pond, but A1EK, you're A-1.

Great post, good pointers, all well-done. Quick questions: do you have the CD changer and if so were you able to retain that functionality? Second, I wouldn't mind spending a couple hours on the programming -- once -- but does it have an internal ROM chip or something to remember the settings in case of battery removal or failure?

It sounds as though the total was the rough equivalent of US $300, that is really affordable for full integration, all the extra features and, of course, the nice Bluetooth interface.

Take care and enjoy the re-"tuned" ride,
Greg
HI Gregs210, Yes I get the A-1 !! thanks (By the way used to have a w210 and loved it !)

I didnt have the CD changer and just used to carry loads of CD's in the car, and this was one of the reasons I wanted to get mp3 and the convenience of a USB input or ipod etc ! I also wanted the Bluetooth handsfree and looked at the adaptor but found that this retailed at about $500 so thought it a little epxensive for only being able to add one feature to me car, so opted therefore for the aftermarket Sony headunit which came with all the toys already !

As for the programming it doesn't take 2hrs to programe, what I meant was it took me two total to wire and fit.! The programming was only about 10mins and only needs to be done the one time, and is easy once you get the hang of it. As for losing its internal memory settings to work with your car steering wheels, dont worry as its 'non-volitile' so even with the battery disconnected it will keep your settings etc.

One other bonus is that if you wanted to change the function of your steering wheel buttons you can, for example, use the track buttons to change the source instead of scanning etc, or mute and power the head unit, it up to you.! (I kept it the same as it was though)
 
Discussion starter · #5 ·
Great info!
Does this set up displays radio/track information on the instrument panel display?
Unfortunately not, that display just says " Audio " . However when I press my left button to search through the tracks the display on my stereo changes with the song name etc. and the fact that I can stick in a 10GB USB stick that can hold thousands of songs outweighs the fact I dont have the dash display. One cool thing is that when I remove the USB stick, and put it back in a few days later it goes back to the exact song and position I was listenign too.!
Also my Bluetooth phone calls and streaming are excellent, and I can use my Smartphone with TomTom on, having the sound come through the speakers or if i've got a film playing on the phone the same thing !
 
Discussion starter · #7 ·
Yours benz is nice...
Many thanks Formoque, I havn't done that much apart from the wheels and suspension to get it looking right! The body work is standard which I like, nice and clean. I was thinking of a front lip or rear lip spoiler.?
 
Discussion starter · #10 ·
Can you also program the phone buttons (pick up/hang up) on the steering wheel to have specific functions on the head unit?
I tried to do it but nope sorry..
 
Discussion starter · #13 ·
can u tell me what wiring harness adaptor you used to plug the aftermarket unit into the cars harness?
I didnt change the harness, just plugged the new one into the Merc one as it was a standard fit. I used a multi-meter to just check the power supplies and the speakers all worked fine.
 
Discussion starter · #15 ·
Hi mate, I have a CLK 230 Komp, 2000. I am also based in the UK, London.

I have replaced my stock radio with an aftermarket one. But my I can't control the volume on the steering. Do you have the link to the adaptors u got from the US?

cheers
Hi mate.

Depending on the model of your stereo you will need the specific adaptor, I have Sony, and I think that Pioneer work with the same module.

The website that do the modules is Welcome to Pacific Accessory Corporation , you can email them techsupport@pac-audio.com and tell them your stereo module and care type they will then tell you what you need. I however bought my two units via a distributor on ebay and I think in total inc shipping it cost me about £55. Bascially one unit coverts the signal from the car and the other converts the right signal to work with your brand of stereo. I have had them working in my car faultlessly for about 1 year just using my steering wheel buttons.!

try looking on ebay .. good luck
 
Discussion starter · #18 ·
Hi A1EK and other members.

A update on my quest to get the steering wheel controls to work.

Car 2000 CLK320 (W208)
Stereo (Sony XAV-612BT)

I could not get the steering wheel controls to work with the PAC SWI-CP5.
I tried everything and even with some help from their support team, it wouldn't work.

Time for Plan B

I have now purchased a SWI-CAN2 & SWI-RC.
I connected them up over the weekend, but still not good.

The SWI-RC is set up for version 2, but it does not detect the inputs from the steering wheel.
There isn’t a problem with the buttons on the steering wheel as they perform different functions.

I think the connection from the SWI-CAN2 is ok.
There is a LED inside the unit (not detailed in any of the PAC documentation) that comes ON when I hook up the unit to the original stereo CAN BUS wiring.
If I reverse the wiring it goes off, so I assume that LED ON indicates a correct connection (I tried both as part of troubleshooting, but went back to wiring so that the LED went on).

I tried to program the SWI-RC unit up when the Instrument panel was in its “normal” state (showing Total KM’s and odometer) as well as the “Audio” state (showing Audio (with 4 dashes – as there is no interface with the original radio)).

The SWI-RC unit configured up for Version 2 OK (when you turn it on, the LED comes on twice), you can erase any existing configuration OK (LED goes and stays ON), but it does not detect the inputs from the steering wheel.

Any ideas ?
Any help would be appreciated, I have requested assistance from the PAC support team, but nothing yet...
Sorry for not responding mate, let me read through your info and i'll see if I can help
 
Discussion starter · #19 ·
Sorry for not responding mate, let me read through your info and i'll see if I can help
Okay so I need to think back a few years but will try and help you out.

You were correct in getting the two devices (SWI-CAN2 & SWI-RC) as you must have both. This is because the SWI-CAN2 interfaces with your CLK Canbus then the SWI-RC interfaces to the respective stereo, in your case a Sony. I've checked on the website and you have the correct models.

I simpathyse with you on the help guides as I too found it hard to get my head around too !

Now you seem pretty good at electrics so I am sure you have followed the instructions correctly and wired the two units as they should. You are correct there is a little led inside the unit that blinks etc and as you have pointed out you have correctly set the program for version 2 which should be for Mercedes.

So at this stage you should find when you turn on the ignition (on all the way just before starting engine), the little red LED flashes 2 times on the SWI-RC yes?
Now to program the buttons there is something that took me ages to figure out that you need to ensure you do first before proceeding, you MUST select the screen on your Mercedes dashboard that is normally displayed when you change radio stations or CD tracks etc. It will probably be blank for you and not have the normal 'Audio' text as this is what happend when you use the adaptors unfortunately, but never the less you need to get this screen up on the dash first.
Once you have the correct screen on your dashboard, THEN start programming.

To Program:
(Make sure you have the 'Audio' screen showing on your Mercedes dash which is probably blank)

Then turn ignition on just before starting engine, the SWI-RC flashes twice.

Press the program button on SWI-RC briefly for 1-2 secs then release, you are now ready to program.

Start to press one at a time on the steering wheel buttons to program, to give you a guide on my unit the order was:

1. Vol UP (press vol up on right of steering wheel)
2. Vol Down (Press vol down on right of steering wheel)
3. Mute (We do not have this button on CLK so skip by pressing the SWI-RC program button once).
4. Track Up/Seek (Press left seek up button on wheel)
5. Track Down/Seek (Press left seek down button on wheel)
6. Source (Skip as above with program button)
7. Preset Up/Disc Up (Press left Up button on wheel)
8. Preset Down/Disc Down (Press left Down button on wheel)

Once all programming is done wait 5-10 secs and the LED will flash three times indicating the end.

Try it out and see !! (Finger crossed for you)
 
Discussion starter · #21 ·
I was going to do a quick video but my battery is getting low as I have been off for a few days and this I know effects my 2 PAC units, they start to work again after driving for 15 mins but (this may just be my car not yours.)

Reading your reply you do not need to have the screen blank in order to program sorry you just need to have that screen active. What you will find is that the screen shows blank when you have programed the unit and when you scroll through on first starting your car it will probably show 'Audio' then after you press for example the volume it then just goes blank (Hope this is clear).

So try again, it sounds like you were almost there.

to Recap:

Get to Audio screen or blank, turn key and your PAC device will flash twice.
Then press and hold the program key for a couple of secs and the led comes on.
Then go through the sequence, eg. Vol up (Watch for LED to blink and acknowledge) then Vol Down (LED blinks again) etc etc.
 
Discussion starter · #22 ·
I've added a little video to help explain things, hope this helps !

 
Discussion starter · #24 ·
Hi blue_clk320_cab

Dont worry about the screen not going blank, I think this is simply because you have haven't fully programmed the unit yet thats all. I found that the dash display goes blank once you have the units programmed and then press a steering wheel button, prior to that it will say 'Audio'.

Another point to mention is that I have found from experience if the car battery is disconnected or is low in power due to not using the car for a long period of time or you have left your lights on for example, the PAC units take about 15mins of driving the car to start working again which I believe is due to insufficient Amp current. You also cannot program the units when the battery is low it seems so ensure you car battery is nice and charged ! This is rare that it happens but other than that once you get the units working it should give you trouble free use for years and years !

Let me know how you get on.
 
Discussion starter · #26 ·
Thanks again A1EK

It appears to me a bit of a chicken and egg scenario, whereby the display will go blank only when the SWI-RC unit is programmed, but you can't program the SWI-RC unit until the display is showing blank.
It really was doing my head in...

However, at some stage the stars aligned and I managed to program the SWI-RC (still connected via the SWI-CAN2 for others following the discussion).

As stated previously, I could only program 4 functions, but better than nothing.
I still am not sure how you programmed the next/previous system buttons as every time I press these keys when trying to program the SWI-RC, the display goes back to the main odometer option (I know it works from your video, just not sure why).

The steering wheel controls have been working intermittently now (based on a "Blank" display (works) or a display that shows "Audio" (doesn't work).

I thought it might be something to do with a loss of power when I turn off the car. So I wired up the SWI units to the constant +12V supply rather than the accessory +12V supply. This seemed to work for about 3 goes in a row, but wasn't working this morning, but much to my frustration, came good again this afternoon.

I suspect that the interaction between the car and the SWI units is the root cause (as the display indication, Blank or Audio, pretty much tells me if the steering wheel controls are going to work when I start the car).

It appears a lottery at this stage every time I get in the car, but I will keep my fingers crossed and try to look for a pattern of miss behaviour.

Based on your point regarding power, did you wire yours to the +12V Accessory (as specified in the manual) or via the +12V constant ?
I connected up my charger whilst I was troubleshooting and programming to ensure the voltage level remained high (these units only draw about 20 milliamp's current, but they might be susceptible to problems if the voltage gets too low, based on you experience).

Thanks again for your assistance
Regards blue_clk320_cab
Hi there.

The screen being blank or saying audio is fine, as mentioned it goes blank when programmed, but do long as you are on the screen for audio thats all.

It was that long ago when I wired it up that all I can tell you is I followed the wiring isntructions in the manual.

You are correct that if the power is low it make the SWI units go a little strange, this is from experience. So for example in the winter when you use more battery power, on occasion the steering wheel buttons do not respond straight away, but I know after driving for a bit to charge up the car they will work again. This is also true when programmin the units as well, if the battery is not strong for some reason it does not program succcessfully, so try and charge your car battery perhaps.

You said that you could only program 4 commands? is the sequence the same as mine? ...

1. Vol UP (press vol up on right of steering wheel)
2. Vol Down (Press vol down on right of steering wheel)
3. Mute (We do not have this button on CLK so skip by pressing the SWI-RC program button once).
4. Track Up/Seek (Press left seek up button on wheel)
5. Track Down/Seek (Press left seek down button on wheel)
6. Source (Skip as above with program button)
7. Preset Up/Disc Up (Press left Up button on wheel)
8. Preset Down/Disc Down (Press left Down button on wheel)

What commands did you manage, if you can list them down .
 
Discussion starter · #28 ·
Hi A1EK,

As stated below (03-14-2016 12:15 PM), I got up to step 6 (4 buttons programmed) and the next/previous system buttons could not be programmed.

Every time I press these keys (next/previous system) the display goes back to the main odometer or the no malfunction option.

In the end, I just programmed the 4 buttons that would work and skipped through the remainder.

Regards blue_clk320_cab
Hi Blue clk320 cab

When you say step 6 is this following the instructions from the SWI packaging. Remember that my devices were bought about 8 years ago and may be different set up.

As mentioned, can you list what the programming sequence are that you were given?

eg
no.1 Vol Up
no.2 Vol Down
etc
etc
 
Discussion starter · #30 ·
I've read through the manuals and checked on the website for PAC to make sure that you have all the right details and it looks like you have.

The only thing I would like you to check is that for Mercedes the SWI-RC I think should be on Version 2 for Mercedes.
The other unit is for your stereo and I the dial should be on no.7

Also for the steps you mentioned, Sony devices should be:

Vol up
Vol Down
Mute
Preset up
Preset down
Scource
track up
track down
skip
skip
skip
skip
skip

IS this correct?
 
Discussion starter · #32 ·
Hi A1EK

SWI-CAN2 switch set to 4
SWI-RC switch set to 7
The SWI-RC programmed to Version 2.

The button sequence as per your example/s below.
But as stated several times, I couldn't get the sequence of buttons working the way you did.
Every time I press the lower LHS steering wheel buttons the display and function changes and the SWI-RC can't be programmed.

I've looked all over the net to work out why you have set your SWI-CAN2 to version 4?
For the small dial on the side of the unit I believe this should be on Version 2.
 

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Discussion starter · #34 ·
Hi A1EK

I'm thought I had referenced these links earlier
But both instructions on the links below show

SWI-CAN2 switch set to 4
SWI-RC switch set to 7
The SWI-RC programmed to Version 2.

For a Mercedes CLK 2000-2002

Vehicle Switch Setting:
The SWI-CAN2 interface has a rotary switch on the side.
Please set the switch according to the vehicle application chart.

http://www.pac-audio.com/PACProductData/SWI-CAN/1_Instructions/swi-can_connection_diagram_090408.pdf

iPod Integration for your car and More by Pac-Audio - Connecting you to the future

I'm pretty sure the switch on your SWI-CAN2 will be set to 4

Another SWI-CAN2 reference

http://www.pac-audio.com/PACProductData/SWI-CAN2/1_Instructions/swi-can2_instructions_032608.pdf

Note I also tried the SWI-CAN2 on switch 8 as part of my troubleshooting
(Mercedes CLK 320 2003-2004 Mercedes-CAN - this looks like the setting for a W209 rather than a W208, but I was trying lots of things at that stage) but this didn't work at all.

And the SWI-RC references are :-

PAC SWI-RC

http://www.pac-audio.com/PACProductData/SWI-RC/1_Instructions/swi-rc_instructions_061015.pdf

http://www.pac-audio.com/PACProductData/SWI-RC/1_Instructions/swi-rc_viig_32514.pdf

http://www.pac-audio.com/PACProductData/SWI-RC/1_Instructions/swi-rc_vcc_032514.pdf


Regards blue_clk320_cab
Apologies, I've just checked my car and the dial is also on 4, so my mistake as this is obviously correct.

so you have all the functions working with the exception of seek up and seek down (Which should be the same left side arrow buttons as track up and down etc.
Well thats not too bad as you have the main ones, I seldom use the seek buttons anyway.
The only other thing I can think of is that you need to be fairly quick when doing the programming as per my video.
Theres also an older video you may have seen on PAC which I have added the link below:
 
Discussion starter · #39 ·
Its been a while since I did the install and sadly I do no have the car anymore, however I am surprised that there has been nearly 40 posts on this subject as I found the install straight forward enough ? However I am an engineer to trade so appologies if I came across a bit brash !
If you follow the instructions to the letter, you should be fine. The only difficult part was programming, however with the videos etc its easy
 
Discussion starter · #54 · (Edited)
Hi all, without a response from ChrisKol I took a leap of faith based on the associated thread from tpearsall regarding the CRUX SWRBM-57 (http://www.benzworld.org/forums/c208-a208-clk-class/2006465-new-head-unit-connection-options.html)

The installation of this unit was unbelievably straight forward (it would have been easier if I had the original wiring loom and hadn’t cut and soldered the wiring previously, as it came with all the associated connectors)
As I had to reconnect the cabling anyway I took the opportunity to extend the cabling (both the 3.5mm jack and the power and can bus) so that I could install the unit under the steering column (not much room behind a dual din stereo)
It comes with lots of cabling options but you only need to connect (Accessory +12V Power, Ground, Can Hi, Can Low and the 3.5mm lead to the stereo) to get the steering wheel controls to work.

So as to the functionality…
The CRUX SWRBM-57 worked as it should straight away (no configuration, no nothing, exactly as you would hope)

I regards to what steering wheels controls work

When the Instrument panel was in its “normal” state (showing Total KM’s and odometer) the volume controls work but not the other options.

If you use the next system option to change the Instrument panel option you now get an “Audio” state (showing Audio – this time in a slightly larger font that previous)
The “Audio” state enables a couple of additional steering wheel function buttons
Using the picture below to reference the buttons that work

3. Next System (Preset Up/Disc Up) – Does not work to control the stereo (because as you press it, it changes the function of the display - display goes back to the no malfunction option)
4. Previous System (Preset Down/Disc Down) - Does not work to control the stereo (because as you press it, it changes the function of the display - display goes back to the main odometer option)
5. Next display (Track Up/Seek) - This works as Radio Seek Up (Track Up/Seek)
6. Previous display (Track Down/Seek) - This works as Radio Seek Down (Track Down/Seek)
7. Increase Volume (Vol Up) - This works as Increase Volume
8. Decrease Volume (Vol Down) - This works as Decrease Volume
9. Phone Off Hook (Dial) – Does not work
10. Phone On Hook (Hang Up) – Does not work

I did check with the CRUX team to see if they had an application to reprogram or map the buttons but they indicated it was not possible (despite a USB connector on the unit).

The CRUX SWRBM-57 doesn’t offer the hope of additional functionality as the PAC units proposed but didn’t deliver (CPI-SWI2, SWI-CP5, SWI-CAN2 & SWI-RC combination).
I never tried the original combination that A1EK got working (SWI-CAN2 & SWI-PS combination) as I could not source the SWI-PS.
I also didn’t try the other combination (SWI-CAN2 & SWI-JACK combination) that might have worked as I could not source the SWI-JACK (replaced by the SWI-RC – which wouldn’t work)
The CRUX SWRBM-57 also worked, unlike the Axxess ASCW-1 which promised considerable functionality only not to work at all.

All in all I have to say I’m extremely happy with the CRUX SWRBM-57 (despite it being reasonably expensive at over US$100 delivered to Australia)
It does the basics well which is the most important thing.
The volume should work whatever screen you are on.
I had a quick look at what I used and found them on ebay.

http://www.ebay.co.uk/itm/New-PAC-S...o-Interface/131300890819?epid=1742274148&hash=item1e922498c3:g:R4AAAOSwPe1UHJtB
https://www.ebay.co.uk/i/2817603978...merchantid=10002454&poi=&googleloc=9046934&device=c&campaignid=207297426&crdt=0