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

SL/R230: Seicane Head Unit Install Write Up

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Old Nov 16, 2021 | 02:34 AM
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Seicane Head Unit Install Write Up

Hello all,

Last night I posted about some issues I’ve been having with Seicane. Since their customer service is absolute garbage, I took matters into my own hands to try and wire everything in with their 6 meter cable. The reason I purchased the head unit is because I replaced my factory Bose amp twice and couldn’t justify spending another dime on a half decent 17 year old system. I’ll go through the steps below and try write everything as I remember it.

There are plenty of threads and tons of info on other sites about removing the center wood trim, rear storage bins, etc. to access the necessary wires, so I’m going to skip that.

Seicane sent me a short harness with three ends; one to plug into the head unit, one for the CAN BUS decoder, and one to plug into the car. Aside from that, you’ll also receive a 6 meter long cable (if you choose to at least), a harness with different RCA’s (this will be important later), and the optional backup camera, USB connectors, and CarPlay dongle.

The CAN BUS decoder comes with three different adapters. It’s important that you find which one fits your car because without it, the head unit will not turn on. You’ll be using the shorter main harness for this. One end of the adapter will connect to the car’s harness, and the other to the decoder. The decoder goes to the first harness I mentioned (the main one that plugs into the back of the head unit). Step 1 is done.

Step 2… connect power from the car. This is very simple as you’ll see the harness coming from the car. This is the only one that is actually “plug and play” and is a direct fit.

Step 3… where things get tricky. Now you have to cut into both harnesses. Since the only part of the 6 meter cable that gets used is the speaker wire, you don’t necessarily need the 6 meter cable, but I had it, so I used it. Anyways, fortunately, main harness on the 6 meter cable that plugs into the head unit is the same as the short harness. So, this means the speaker wire in the short harness is exactly the same as the long one. Cut the speaker wire from the short harness, and connect it to the long harness. Since everything is color coded, it’s actually easier than you think. When you’re running the wire to the back to the original amp’s harness, it’s important that you go under the shifter, otherwise the wood trim will not sit right after you’re done. (Ask me how I know :/). I was able to tuck the rest of the wire under the leather on the side of the center console, but you can run it under the center storage box if you choose to. Seicane does give a pin out diagram of the harness on the bottom of the head unit, so connecting the wires is pretty straightforward. Pics of the seicane pinout as well as the factory amp pinout are attached.



When I wired the speakers, I fused the door speakers and the bass loudspeakers together by side. Also, since the seicane pinout shows two separate wire sets for the rear speakers, and the car only has one connection for it, I used the second set for the center fill. Both of these work great and I recommend doing it in order to utilize all the speakers in the car for better quality.

Now onto step 4. At this point, you’re wired for power and sound. Also, I forgot to mention, the steering wheel controls do work on this unit via the CAN BUS decoder mentioned in step 1. At this point, you’ll notice that you have practically no bass in your car. This is because the Seicane cable does not have a subwoofer output, however, the short RCA harness does. Unfortunately, Seicane again dropped the ball with this as they did not send me any type of wiring for it, so I went out to my local BestBuy and picked up a Kenwood KAC-511 monoblock amp, an RCA cable with two male ends on each side, and a connector to bring them in as one, since the Seicane head unit only has one female end. You’ll want to run the wiring for the sub back to under the rear left storage box, just like you did with the 6 meter cable, to where the factory amp was. Next comes wiring in the amp.

Step 6. I used the constant power and ground from the original amp for the new one, since I was not interested in running new wiring to the battery. Perfect that the constant power is fused already. For key-on (remote) power, I used some generic 14 AWG wire I had and spiced into the hot wire for the cigarette outlet up front. Run this wire back the same as the aforementioned wires for the speakers. Turn your key to the “on” position to make sure your amp is working. Now, use the RCA wire you ran from the head unit to plug into the input side of the amp, and use wires 11 and 19 from the factory amp as the output. Tune your amp, and you’re good to go.

Step 7, hook up the antenna adapter that Seicane sent you. The ADAPTER. The actual Seicane antenna is a POS. horrible reception.

Step 8, hook up your GPS antenna. I put mine outside the car for better reception. Plug into the back of the head unit and run behind the dashboard, under the glovebox (you can just tuck it, no more disassembly is necessary for this), and out the door. I popped the right side A-Pillar out and tucked the wire under there, it’s not seen until it reaches the antenna, which on my car, is mounted on top of the windshield.

Step 9: Set up your options, which in my case are the wireless backup camera and Apple CarPlay. I have not hooked up my backup camera yet, but I did hook up the wireless receive in the back of the head unit. As far as CarPlay goes, another reason Seicane sucks, aside from not answering questions and shipping everything out late, and not providing any instructions, is because they sent me a bad CarPlay dongle. Thankfully, I had one from another car I had with an Android head unit, but I recommend you check other options online and order one as well. CarPlay works great and is most of the reason I purchased this unit.

Step 10: put everything back together exactly how you had it.

This install took me quite some time, but that was primarily because I had no instructions. If anyone is interested, I definitely recommend giving it a shot, and most people can DIY it. The head unit itself is pretty good; I love the OEM look and the functionality. Sound quality could be a bit better, but I’m not gonna complain. Seicane as a company though, is a joke. They have provided me no help, and I feel like I know more about their product than they do. If anyone has any questions feel free to post and I’ll try to answer them as best I can.


almost forgot… attached is also a pic of the amplifier I installed for the sub. I removed the CD changer and mounted the amp in the rear storage box.




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Old Jan 13, 2022 | 06:49 PM
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Hello Jakal and thanks for the detailed documentation. I too am installing a Siecane head unit however i am using the stock Bose amp with the d2b adaptor. Just wondering how you made out with the Steering Wheel controls. I thought there would be a place in the settings where you could configure them but i cant find it. My volume and phone buttons on the right work properly but the buttons on the left side of the wheel that are used for the instrument cluster are also mapped to functions in the head unit which is obviously a problem when navigating the instrument cluster changes the radio station. Any tips?
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Old Jan 13, 2022 | 09:41 PM
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Originally Posted by djpjd
Hello Jakal and thanks for the detailed documentation. I too am installing a Siecane head unit however i am using the stock Bose amp with the d2b adaptor. Just wondering how you made out with the Steering Wheel controls. I thought there would be a place in the settings where you could configure them but i cant find it. My volume and phone buttons on the right work properly but the buttons on the left side of the wheel that are used for the instrument cluster are also mapped to functions in the head unit which is obviously a problem when navigating the instrument cluster changes the radio station. Any tips?
It could be that you have your canbus unit configured incorrectly. I did not have that issue with mine. The canbus adapter (I believe its called an adapter at least) is the little black box that plugs into the back. If I remember correctly, the right switch setup is 1-down, 2-up, 3-down, 4-up. See attached pictures. Hope this is helpful.



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Old Jan 18, 2022 | 03:58 PM
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It turns out my problem was in the settings of the head unit. I had to go to the factory settings (Password=318) and enable SWC with CAN. When I backed out there was an app called wheelkeys installed that I could now program my buttons with.
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Old Aug 11, 2022 | 07:57 PM
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Hello Jakal702. It's been a few months since you posted on this. How's the Seicane doing? Do you like it? Sound quality, features, reliable? I'm thinking about installing one in my 2003 SL. Hopefully, I can keep the factory amps.
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Old Sep 13, 2022 | 11:48 PM
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Originally Posted by MBGuz305
Hello Jakal702. It's been a few months since you posted on this. How's the Seicane doing? Do you like it? Sound quality, features, reliable? I'm thinking about installing one in my 2003 SL. Hopefully, I can keep the factory amps.
Sorry for the late response, I just saw you reached out… I’ve since sold/replaced this car, but I did have the seicane in for about 8 months until I got rid of it. I will say the head unit itself is ok, but a good amp is required. I tried to run the speakers directly off of the head unit and it sounded like garbage. Sound quality seemed ok in the beginning but seemed to rapidly degrade (maybe that was just me). I later installed a 4 channel amp mounted in the rear left storage bin, just above where the factory amp sat. I would recommend installing a four channel amp to run the speakers in the cabin as doing this increased sound quality tremendously, and the Bose amp’s in these cars are known to fail (this was my reasoning for doing this system. My car went through three amps in a matter of months and it was not worth investing any more time/money into a twenty year old system). The four channel amp combined with a monoblock which controlled a sub i later installed in the trunk made a perfect sound system in my car. The only downside was the lost trunk space. I did try to use the factory subwoofer initially but it sounded terrible with the seicane. The stock system in this car is rated for very low power, so it wasn’t a good idea to run the factory sub off of an amp, but it sounded so bad with the seicane that I eventually just left it disconnected. I guess at the end of the day, I would recommend the head unit so long as you power the speakers with a good amp. A sub is necessary though, as the speakers in the cabin do not provide much bass and do not like lower frequency sounds.
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Old Sep 15, 2022 | 05:46 PM
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Nice write up Thanks for that
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Old Apr 19, 2024 | 12:46 AM
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Question Android Head unit and old BT Puck removal

Sort of related question,
Got sick to death of pissing around just trying to steam my own music to the ML, bit the bullet and bought a the new T'EYES CC3 2K.
So far so good, (mostly), only issue I see so far as I can use google maps ok, but I don't like the way it runs a route with Waypoints. When you get to a waypoint it gives a blank green screen, then you have to press the "Back" icon and then continue, probably not legal in my state Victoria Australia under the new Phone laws in cars.
Also it has a built in Voice command, and doesn't work with OK Google, (unless you tap the Google map microphone icon).
BTW all SW buttons work except front to rear fade.

Anyways, now I only have one question, can I remove the old BT puck? installer says best leave it but i would prefer to have the extra space.

2006 ML320 CDI 4Matic RHD.
Harmon Kardon MOST sound system

Last edited by Tex260Z; Apr 19, 2024 at 12:49 AM. Reason: Added info
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Old Jan 11, 2025 | 10:16 AM
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I am reporting the above post as inappropriate for this forum. It is also spam as it is selling something. Probably created by a bot which tries to get an account at any open forum.
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Old Jan 11, 2025 | 05:46 PM
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Tex is in the wrong forum for his car but I guess if he was trying to sell something, then he'd be giving it a better crack than 'it's sort of OK, except for '...
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Old Jan 11, 2025 | 06:21 PM
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No, whatever I reported has been deleted already by an administrator. It was selling IT training services. They should have deleted my post too. (In forums where I am a moderator, I delete the spam and any complaints about it.)


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Old Jan 12, 2025 | 01:40 AM
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Aha!
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