ThatsMyDawg

Hello all!

Most already know that some R231 models do not come with an Apple CarPlay factory option, bummer. However many of the facelift models do have that factory CarPlay option. Great for them! As an apple guy for many years now I too wanted CarPlay in my beloved SL. I loved CarPlay in my prior Cadillac Coupe and was disappointed to learn it was not in the year SL that I purchased. (15) I like the factory head unit look and I also did not want to buy a new head unit with built in CarPlay, because they are expensive. With a $700 + possible cost or more for a new/quality head unit plus installation cost, as well as sometimes the loss of factory functions, made me look for another option. Audio shops specifically told me (more than one) that CarPlay was not an option for my car, but once again this forum has provided information to contradict those brick and mortar audio shop "experts" that said we could not have CarPlay. The RoadTop unit can be purchased online for $279 to $299. I hope this thread will help the pre-facelift SL owners and possible others that would like to add Apple CarPlay to the SL, as well as Youtube and screen mirroring to their cars. This thread took a very long time to post and I am gassed out to be honest. Please forgive typos, grammar errors and the different sized pictures. I have no idea why the pictures are all different sizes, because I just posted them and changed nothing about them.

Disclaimer - I am not an audio expert and have never worked on car radios in my life. I was willing to try this on MY CAR, because I am that kinda guy, but you have to make your own choices. I am not responsible for any fitment, or functionality issues. Damages, or injury that may occur to you, your car, your systems, or persons when attempting this installation. Attempt this modification at your own risk. I did and I am so happy I did. I hope this helps you!

I would like to acknowledge forum member JettaRed who mentioned CarPlay was an option and offered me installation support. JettaRed encouraged me and even offered phone help in case I got stuck along the way. I appreciate you buddy!

Lets get to it...(Time to complete- 2 to 5 hours)


This is how the unit arrived and what is inside.



Well packaged and labeled well. There is nothing else I needed to purchase except the T20 bit which most of you probably have laying around the garage someplace. You will need some plastic pry tools, but many have those already. A four to six pack of pry tool are less than $10 online.



You will need to remove the trim from both sides of your SL
It is easy, but I was very nervous. I started with the passenger side.
Simply pull the trim a little to get it started then continue towards the rear of the car.
Just pull a little, don't go crazy.
When you get to the middle move your passenger seat forward to get to the back part. Unhook your seat belt at top of your seat as mine kept tightening to prevent seat movement. It did its job!.









Next remove the lid from the rear area passenger side battery holder.
It doesn't lift up like the one behind the drivers seat, but it does just pop off with a good tug.
The trim ends between the battery lid and the console so it is kinda tight without removing the compartment lid.
Once the top is off pull the trim towards the front of the car to clear the tabs. Sit it outside someplace away from the car so you wont step on it.






Ignore the little black cord that you see. That cord is to my dash cam wire that I ran under the console trim prior to this install. You wont have that wire.


Now onto the drivers side. It's the same as the other side, however you will have to remove (pop up) the trim above the steering wheel as well as move the lower steering wheel trim out of the way.
The top part pops off easily and the bottom you just move it towards you out of the way.
Use your lever to move your steering wheel as close to the drivers seat as it will go before starting the steering wheel trim procedure. Don't remove the lower part completely!














Next - There are 4 screws T20 on each side the center wood trim that have to me removed. 3 Vertical and the last one holds a small plastic bracket that is horizontal. Just take a picture, or remember how the bracket pops in. It is easy.

You will have to pop off the trim around the head unit and ac controls.
I was worried about breaking something but it was easy.
Just don't pull super hard and after you get started on the corners use the plastic pry tools to help.
Open your glove box door to get it out the way. You don't have to remove the glove box door, but you can if you want.





Edit











Repeat on the drivers side.

ThatsMyDawg

Once you have the ac/radio wood trim free there are 3 clips on the left that you must remove. The far little one pulls out with a push of the tab. The other two have swing arms that release after pushing their tabs.












Next -
There are two more screws holding a little bracket inside where the head unit sits. One on each side of the head unit. All you have to do IS LOOSEN THEM, DO NOT TAKE THEM OUT. Loosen the screws enough that you can tap the bracket and it moves/wiggles a little left and right. AGAIN do not remove that bracket, or those screws completely.. Unscrew them a little then use your screwdriver to see if the bracket has any play. If you can move the bracket a half inch to the left and right with your screwdriver you are good.




Next-
Place a towel, or cloth on your cup holder flip up lid, so you wont scratch it when you pull out the head unit. You will be sitting the head unit on the cup holder lid, so cover it to protect it. The head unit is heavy. I just used bubble wrap that I already had handy. Wiggle and pull the head unit towards you about an inch and then unclip the white ac control clip at the bottom right of the unit. You wont be able to pull the head unit out far unless you unclip that white clip bundle of wires.





Next-
The head unit should move toward you easily now. (reminder- you should have unclipped the ac wire (white lower corner closest toward passenger side) to be able to pull the unit toward you. Don't force anything

Next-
Grab your new wires that came with the unit.
Grab the blue Y wire. One end goes in the new unit as pictured, one end connects to the wire with the grey plug that you must remove from your head unit and the other blue end goes in the head unit where you just removed the grey plug wire. Yes, the unit wire is blue and the connecting plug is grey.











Next you have to remove the fiber optic lines from your head unit harness and insert them into the new harness. They are two bright orange wires that just pop out after you push a little tab. They pop right in as well.
You have to swap the factory wire harness with the road top harness as well.The Road top harness looks just like the old one from your head unit. (go back and look at the supplies on my seat, you will see it there) You're just unplugging the head unit harness from the factory unit and then plugging it into one part of the new harness. The other part of the new harness goes into the head unit essentially replacing the factory connection that you just removed









Next-
You need to figure out where your new unit is going. You could try to put it behind the head unit, or in there off to the side, but it is going to be a tight fit. Not impossible, but tight. I, like JettaRed decided on the glove box. If I ever need to replace that unit I can just swap it in the glove box. The other method I would have to take everything apart again to get to it. Nope. I didn't have time, but eventually I am going to make a cover to cover the head unit thats in my glove box. After I wrap the future cover with cloth similar to the glove box it will just look like a narrow glove box.

I had to run the wires in the dash, behind the head unit space and down around to the glove box. I just used a zip-tie and fished each one around to the glove box factory cut out and then pulled them through. The cut out is hard to see, because it is covered with cloth.I needed to bend the cut out open a little more than what the factory supplied to get the wire and plugs through it. Once through I bent the opening back to as close as it was originally.

Next
Connect the wifi antenna to the new unit. Instructions state do not put the wifi wire on metal, so behind the radio is a no go.
Connect the USB
Connect the Can wires.

Its hard to see, but if you look you can see the wires as I fished them around behind the dash and over to the glove box. Just look closely at the picture through the holes and you will see the wires in there. You might have a better way, but it was relatively easy to do. Easier than I thought. At first I was like "how the heck am I going to get the wires way over there" lol!
You have two ground wires that you will need to attach to each other, or you will get horrible static. I thought they didn't label one of my grounds, but one wire was down in the dash that didn't make it to the glove box, so I had to fish that one over by itself.












Next you just have to run the usb connector over to wherever you want that to be. The USB is used for any future software update, or you can use it as a phone charger plug in. I just placed it on the passenger side, so the passenger can plug up a charger cord without having to use my charger in the console. Whatever you want to do.
Lastly you have to run the Aux cable to your console. This is a must for you to be able to hear the audio through your cars system. I just ran it along the sides under where the trim will go.You will have to drill a hole in your console to make the console connection to the aux wire. I didn't drill the best hole, but when I do the glove box cover I will tidy up the hole a bit with cloth as well. Be careful not to mess with your led ambient console lights that you will see once you moved the trim covers prior. They look red in the picture. It would probably be easier to remove the center console to make drilling in it easier and more accurate, but. I aint got time for all that lol.






Next you have to test everything out to make sure everything is working, before you button everything back up.If all is good reverse the radio removal and trim steps etc. to close her back up. If you have a blank screen, or other issue unplug the wires from the unit, turn your car off, plug the unit back up and then turn your car back on.Note: There has been a mention that some out of the USA had a scrolling screen issue after install and that particular problem is connected to a "split screen" option/settings, in some MB. From my understanding the fix is not a setting you can simply adjust. Member @fantasticn seems to have found the fix. It seems that you will need a firmware update from RoadTop to correct the issue. This seems to be a non USA issue as we do not have split screen options in the USA.

You should then be good! You will likely be way faster than me at this install, but it took me 5 hours. I was just taking my time, checking and relying to emails, sipping on my drinks from time to time and looking at nosey neighbors trying to figure out what I was doing tearing my car to pieces. Not one offered to help lol. There are options to add front and rear cameras to this systems, but I already have a rear camera and did not want a front one. Any unused cords were tied up in the glove box..


All buttoned up with passenger charging USB.







Enjoy your CarPlay!

Ruppster

Thank you for taking all that time to walk us through this. I even think I could do it now! Much appreciated.

Wolfman

Great job and a very helpful thread for other members!
Made it a sticky…

ThatsMyDawg

You can!!! Trust me if I can you can. And I mean that 100%

jrupp

Last question before I pull the trigger on this...Does everything work as it should? Someone had posted (maybe Jetta Red?) that the phone and car seemed to be competing for some functionality. Thanks!

ThatsMyDawg

It works exactly as the factory CarPlay did that was in my Cadillac. There is a second or two delay before it starts when I get in the car, but my Cadillac did the same thing. I disconnected my phones bluetooth from my car head unit and only use the CarPlay now. There is no need for me to have my phone still connected to the factory unit after this CarPlay install. 1000x better. You can't bluetooth music stream and use CarPlay music.. They will fight and compete with each other. I just say what I want to happen ie: Hey Siri get me directions to, hey Siri Call my wife, Hey Siri Shuffle all songs, Hey Siri skip current song, etc. and now I don't have use my iPhone to do that.

You can also manually control the music with the iPhone. So far the YouTube and airplay is a little buggy based on my wifi or hot spot service, but those two are not even options in factory CarPlay, so I am good if they never get better. I was watching YouTube while driving yesterday (please save me the lecture lol- I have watched in motion video for over 15 years without an issue.) and it was some hesitation during playback similar to if you had a weak signal at home while streaming a movie on tv. If you want to wait a week for me to have played with it for more feedback that would be cool, but if I never even use YouTube, or airplay I am totally happy with what the system does and any shortcomings.

Ruppster

This is truly one of the most helpful posts I've seen on this forum, which is reflected by the fact that Wolfman elevated it to Sticky Status. Thanks so much for your time.

ThatsMyDawg

I appreciate that. I hope some people are helped by the thread...

JettaRed

iTrader: (1)

Yes, I discovered that if you connect the car’s Bluetooth and the Road Top Bluetooth, you will have some problems. For me, it was receiving phone calls when in CarPlay mode. So, as Dawg said, I “Forget” the car and only connect to CarPlay.

althethird

Great write up indeed.

I placed my RoadTop unit inside the plastic passenger footwell cover that houses the cabin filter. There’s a small cutout under the glove box that’s just large for the unit and the wires.

Also, I did not use the Aux/MMI cables for my installation. Since I did not use the Aux/MMI cables, there was only one wire to ground to remove static in the audio… that wire was grounded to the body of the car with a screw that, if I recall correctly, attaches the dash plastic frame to the car which was near the middle of the radio on the passenger side.

Because of the ease to access the unit, I did not install the USB cables because I connect to the unit wirelessly; but, if I needed to perform an update, the footwell cover is easy enough to drop so that I could then attach the USB cables to perform a firmware update.

The only issue I have is using CarPlay Bluetooth for calls. I find that I have to turn the volume up to hear calls but the music’s volume is deafening when the call is disconnected. Because of this, I have the both the MB Bluetooth and RoadTop bluetooth connected at the same time. This works perfectly because increasing/decreasing the volume of a call has no impact on music volume. The only caveat to this setup is that you have to use the console dial to accept a call instead of the steering wheel.

JettaRed, I’ll update this post with my specific settings that works perfectly every time.

ThatsMyDawg

Much appreciated.

I have no issue hearing calls at all. You can change the music and, or speaking volumes though settings. Glad you completed the install and are up and running.

JettaRed

iTrader: (1)

Sometimes my screen goes black in the CarPlay mode when I first start the car. I simply disconnect the Bluetooth and reconnect to the CarPlay unit on my iPhone and that fixes it. This usually happens (when it does) when I put the car in reverse before the CarPlay has fully connected. The reverse camera seems to interfere with the video or something, but the fix is easy. And, it happens once in a while, so no big deal.

ThatsMyDawg

Interesting. I have not experienced that

JettaRed

iTrader: (1)

I think it's more of a phone problem than the CarPlay unit. Or a timing issue that I put the car into reverse before the CarPlay fully activates. I have an iPhone 13 Pro and probably a lot of crap running in the background.

althethird

ThatsMyDawg, can you post a screenshot of the firmware your unit is using? I occasionally have the panic inducing black screen that JettaRed mentioned.

althethird

To route calls through MB Bluetooth instead of CarPlay, I have Using Car's BT Phone turned off on my RoadTop device. When you place your first call from CarPlay, select MB Bluetooth under the speaker option on the phone's call screen... all future calls placed using Siri or CarPlay will be automatically routed to MB Bluetooth. Accepting phone calls requires you to answer the call using the car's rotary dial and then selecting MB Bluetooth under the speaker option on the phone's call screen. I have yet to figure out a way to have incoming calls default to MB Bluetooth instead of CarPlay. As mentioned earlier, you have to use the rotary dial to accept incoming calls using this method.

ThatsMyDawg

Yes I will when I get home from work later tonight. It’s been raining Gremlins and Pokémon for the last few days and so I am driving the SUV.

Off hand the only time I have seen a black screen” is once when switching from screen share back to normal car play. I toggled off my connection and reconnected to clear it. Even if that were to happen regularly (only happened once) I would be fine with it, because as I have said here and in other posts the factory installed carplay that was in my Cadillac had strange quirks at times too and that was a factory install. However it would be nice to find out what causes the issue that y’all mentioned.

Edit- I found a pic in my phone from install.


Install pic

althethird

Thanks. All are the same versions that my unit is using.

ThatsMyDawg

Got it.

I have the Phone 12 and I guess it could be that I never jump in the car and start shifting gears (reverse, or whatever). I usually am adjusting my seatbelt, climate controls, windows, or top before I start to drive which takes at least 30 seconds up to a minute. By that time the CarPlay is already up and running. It’s rained for the last few days, so I haven’t been driving the SL. Today and the next few days it should be dry again, so I can try to duplicate that reverse gear rear camera error you mentioned.

JettaRed

iTrader: (1)

It doesn't happen every time, just randomly. Regardless, as you said, refreshing the connection is an easy fix. It's as easy as switching WiFi off and on (or maybe it was the Bluetooth). And the improved sound and other features are more than worth any quirky intermittent behavior.

jrupp

This may seem like a stupid question but which unit do I buy off of Amazon? I have a 2013 SL550. Getting ready to pull the trigger and don't want to order the wrong unit. Thanks!

althethird

That's not a stupid question at all. Here's a link to the unit that I purchased. . It's slightly more expensive through Amazon than ordering directly from RoadTop.com, but I prefer Amazon's quick shipping and flexible return policy. If you order anywhere else or through any other Amazon sellers, please make sure you're getting the second version of the RoadTop unit which is also referred to as Gen2 because you can not use the factory microphone with the first generation.

althethird

Update to a previous post.... I think I may have figured out the low call volume issue when using the RoadTop unit. I discovered the factory phone menu that allows you to increase the reception volume. When in MB's Phone menu, select the Connect Dev. menu at the bottom of the screen, select the connected phone, and scroll to the right and select to edit settings option. Copy of the menus below. I increased my Reception Volume to +1 and all calls placed/received through CarPlay are at perfect volume for the last 3 days. When calls are sent/received, all are also routed through MB Bluetooth automatically and I can answer/hangup calls using steering wheel controls.








With these settings, I have also switched Using Car's BT Phone to "on" under the RoadTop settings.

althethird

Thanks JettaRed. The black screen happened to me today and it was as simple as switching WiFi off and back on to get the screen back like you said. I couldn’t figure out how to resolve prior to your post.