Adding an aftermarket stereo head unit to a Sprinter

We gave in. Even after changing out the front speakers and adding a subwoofer, the Audio 15 stereo that comes as stock in newer Sprinters was just not up to the job.

We chose to replace it with an aftermarket unit from Sony that has Apple Carplay and Android Auto so that we can use our phones to provide navigation and music through the stereo.

The swap-out wasn’t hard, but there are a couple of sticky points along the way. Read on for the details.

Problems with the stock stereo

The Audio 15 unit that came stock in our Sprinter has an interface from the early nineties. To move between audio sources involves tons of button pushes. Because we’re used to phones and tablets we kept trying to touch the screen to make changes.

The unit has no real output power and super-cheap stock speakers. Even though it sounded OK when you were parked up, road and engine noise easily overpowered it.

We were only keeping it in place because it had the Becker navigation system installed. That system isn’t great but because the maps are stored locally it would work even if we didn’t have cell reception. A while back though, Google Maps added an offline map feature so even that benefit of the stock system was wiped out.

We upgraded the stock speakers and added a subwoofer in an attempt to pull every last bit of sound out of the unit, but it still wasn’t performing well enough.

What we chose as a replacement

Shopping for replacement car stereos is not a pleasant experience. There are hundreds of boxes all with near-identical feature sets that look so similar that you’d think they were all made in the same factory and then had different brand names stuck on the front.

Our list of requirements was pretty minimal:

  • Physical volume control knob (yeah, we’re old school).
  • USB input for external music sources.
  • Android Auto/Apple Carplay integration.
  • No flashing lights or multi-color LED crap.
  • Clean, understandable, consistent interface that has large touchscreen targets.
  • 4 channels with sufficient power output to drive our aftermarket speakers without a separate amplifier.
  • Keep the steering wheel volume and on/off hook controls.
  • No need for DVD/CD player. Our music is digital and we don’t want to watch movies on a sub-7″ display stuck in a car dash.

We chose the Sony XAV-AX100 (Amazon link). It has a clean interface, and minimal flashiness.

Sony XAV-AX100 stereo home screen
Sony XAV-AX100 stereo home screen

Interestingly, although it has a double-DIN sized display, the unit itself is single-DIN sized.

The Sony unit is single-DIN in the back and double-DIN in the front.
The Sony unit is single-DIN in the back and double-DIN in the front.

That gives you some extra room inside the dash for other stuff if you want it, like an amplifier, perhaps. The unit has line-out connectors if you wanted to use an aftermarket amp instead of the built-in 20W RMS per channel output.

The back of the head unit.
The back of the head unit.

We looked at several models from Kenwood, JVC and Pioneer but all of them seemed to be designed for a different type of consumer than us. The on-screen icons tended to be garish and faux-3D, and the feature set included lots of options to make the stereo unit stand out from the dash (multi-color LED lighting, etc.) rather than what we wanted, which was to have it blend in.

Installing an aftermarket head unit in the Sprinter

Adding an aftermarket stereo isn’t a straight swap with the stock unit. For a start, the Audio 15 is not a standard (DIN) width or height. It’s wider and taller than any aftermarket unit you’ll find. That means you’ll need to buy a fascia panel insert to go around your replacement stereo and hold it in place.

Your new stereo also isn’t going to plug straight into the socket that the factory radio uses. You’ll need a wiring harness adapter and you’ll probably have to strip and crimp several cables so you can join everything together properly.

The Audio 15 communicates with the rest of the vehicle using the CAN Bus. It displays track and navigation information on the dash. It’s configurable and updatable using the Mercedes STAR computer system at dealerships. No aftermarket unit is going to offer those features, and in fact you need to wire in some additional equipment just to get an aftermarket stereo to respond to the steering wheel button controls for volume up/down and telephone on/off hook.

None of this is necessarily hard to do, but it’s all hassle. if you want to add rear speakers and a subwoofer at the same time, you should plan to leave even more time for the installation.

Step-by-step installation

Here’s how we added the Sony head unit and rear speakers to our van.

Caution: This description may gloss over some steps and it assumes you have mechanical aptitude. It’s not going to take you from audio install newbie to Sprinter aftermarket stereo guru. Read all the instructions that come with the parts you order.

Warning: You’ll be playing with the van’s wiring system.Some vans have airbags behind the panels you’ll need to remove for part of the install process. Be sure you know what you’re doing, and disconnect the negative cable by the accelerator pedal before you start. 

Tools you’ll need

Trim removal tools
Trim removal tools
Wire stripper
Wire stripper
Linesman's pliers with crimper
Linesman’s pliers with crimper
  • Fish tape to pull cables through the dash and headliner.

Removing the dash panels to get access to the stereo and surrounding area

The Sprinter’s dash goes together in layers. You just have to know where to start peeling things away. Each layer reveals the fasteners for the layer behind it. Almost all of the fasteners are identical length T25 Torx screws (thank you Mercedes!), friction spring clips, plastic tabs, or hooks moulded in to the plastic parts.

Take your time, see where the stuck spots are, and you shouldn’t have too much trouble disassembling the parts of the dash you’ll need to access for the removal and installation.

Start by prying off the surround panel that covers the central dash area – the radio and HVAC controls. The set of buttons with the hazard warning switch on them are part of this surround panel. We used our set of trim removal tools for this and all the other panel removal.

Start by removing the central console panel. It has seven spring clips.
Start by removing the central console panel. It has seven spring clips. Three are down each side.
This is the seventh clip - in the middle of the panel just below the stereo.
This is the seventh clip – in the middle of the panel just below the stereo.
Once you have the panel unclipped, remove this wiring connector so that you can put the panel to one side.
Once you have the panel unclipped, remove this wiring connector so that you can put the panel to one side.

Now that the central panel cover is gone, you’ll see the start of the many T25 Torx screws. For a basic stereo install, you don’t really have to remove any other panels but if you are adding a microphone, or messing with the USB and aux sockets in the driver’s side cubby, then you’ll want to go further.

The more you remove, the easier it is to see what’s going on inside the dash area too. If you’re going to be running cables for rear speakers or a sub, HDMI for a second video monitor, a microphone, or any other junk around the vehicle then removing the panels will actually save you time in the long run.

The vent cover panels are held on by one screw at the front of the console, then you just have to pull the whole piece towards you to unclip it.
The vent cover panels are held on by two screws at the front of the console, then you just have to pull the whole piece towards you to unclip it.
The fresh air vents in the top of the center console are a friction fit - just pull up and towards you to remove the driver's side one. This gives you great access to the USB/Aux input sockets.
The fresh air vents in the top of the center console are a friction fit – just pull up and towards you to remove the driver’s side one. This gives you great access to the USB/Aux input sockets.
The top tray or shelf is held on with two screws on the front of the console and two on the top. Then it just lifts out.
The top tray or shelf is held on with two screws on the front of the console and two on the top. Then it just lifts out.

The speaker grilles in the top of the dash are friction fit. We covered their removal in our speaker replacement post, but basically just gently lever them up with a trim removal tool.

Once you’ve got the grilles out of the way you can remove the A pillar cover.

Warning: You might have an air bag behind the A pillar. Work very carefully and with the vehicle battery disconnected when you remove trim around areas that could contain air bags. 

Start at the top, and just pull the A pillar cover away from the pillar towards the center of the vehicle. It’s held in with spring clips and plastic guide pins. Once you reach the bottom, carefully maneuver the top of the cover towards the middle of the dash so that you can unhook the plastic clip that holds the base in place.

Now you’ll see even more T25 Torx screws. A couple of these hold down the panel that covers the top of the dash forward of the driver’s display. Undo the one near the A pillar and the one near the center console and then push the panel away from you (towards the windshield). It will unhook and then you can just lift it clear.

One final set of panels you might want to remove is the section under the steering wheel. Doing this gives you better access to fish wires from the central console across to the A pillar.

First undo the three T25 Torx screws in the base of the two panels, then remove the smaller panel by pulling it downward.
First undo the three T25 Torx screws in the base of the two panels, then remove the smaller panel by pulling it toward you and then downward.
Now it's easy to unclip the larger panel and remove it too.
Now it’s easy to unclip the larger panel and remove it too.

Congratulations. You’ve now destroyed the dash of your vehicle. If you did it carefully, without damaging any of the clips, then it’s all going to go back together just fine. Honestly.

Put all the pieces somewhere safe out of the way so that you don’t stomp on them as you’re working in the dash area. Some of them are quite flimsy when they aren’t held together and supported by other pieces in the dash.

Removing the factory stereo unit

The stereo is held in by four T25 Torx screws, two at the top and two at the bottom.

The factory stereo is really shallow. Once you've undone the four screws you can reach behind and unclip the cables.
The factory stereo is really shallow. Once you’ve undone the four screws you can reach behind and unclip the cables.

The big bundle of cables is held in place with a lever. The bottom edge of the plug has a tab to pull, which then levers up and out. Once it’s pulled far enough (the wires interfere a little), the whole plug will pop out from the socket. Don’t force the plug out – just pull carefully on the lever and the whole piece will release.

The four FAKRA plugs have tiny clips moulded into the plug that hold them in place. Push down on the back of the clip and then pull the plug out from the socket.

That’s it. All the communication with the stock radio happens through the main plug. The four FAKRA ones are GPS (blue), USB (pink), backup camera (green), and antenna (black). Your van might not have all of them if you don’t have the backup camera option or the navigation option.

The plugs from the back of the stock stereo.
The plugs from the back of the stock stereo.

Preparing the dash hole for your replacement head unit

This next step is going to depend on which fascia panel you choose to use to hold the head unit in place.

Because the factory unit is wider than a stock DIN stereo, you need a fascia panel that blanks off the surrounding area and also provides a mounting point for the single or double DIN head unit you’re going to add.

We bought our replacement stereo from Crutchfield, and their configurator suggested the Scosche CR1294B panel. However, that required us to remove the interior plastic that surrounds the radio area (Scosche refers to this plastic as the “radio delete plastic”). That’s a minor problem because that plastic contains the place where the center clip from the very first panel you removed is supposed to attach. Our panel went back together just fine, but somehow it seems like we didn’t need to go to those lengths.

The naked center console
The naked center console – there’s a very large space for the stereo.
The "factory radio delete" piece of plastic that we had to remove (right) and the Scosche fascia panel (left)
The “factory radio delete” piece of plastic that we had to remove (right) and the Scosche fascia panel (left). Other panels fit on top of the right hand piece of plastic rather than needing to remove it.

Scosche also makes the much cheaper CR1292B for earlier Sprinters, which Amazon reviewers say fits at least 2008, 2010, 2011, 2012 and 2013 vehicles. Just looking at the image of that model, it looks like it would require less messing inside the dash. There are a couple of other options available. American International make a fairly nice looking panel (we bought it as a back-up option because the Scosche didn’t seem right) that does NOT require the removal of that piece of plastic. It has a speckled finish just like the rest of the dash area. There’s also this identical looking one, or Metra’s option. Your choice.

Follow the directions that come with the panel. Our CR1294B fitted OK, but there was one area where the instructions made no sense and Crutchfield support couldn’t seem to understand what our issue was. I’ll try and explain here.

In the picture below, you can see the top corner of the Scosche fascia panel with the new stereo mounted in it. Scosche insists that the sliver metal speedclip should be attached to their panel. However, their panel rests in front of rather than behind the plastic tab that is supposed to screw on to it. The tab belongs to the tray on the top of the center console.

Crutchfield suggested grinding the tab off, which would mean the tray wasn’t attached at the front at all. We’re glad we didn’t listen to them. Instead, we mounted the speedclip on to the tray tab, even though the hole through the tab is oversized. It worked just fine for us. It should work for you too.

The speedclip needs to go on the mounting hole for the top tray, not on the mounting hole for the replacement stereo surround.
The speedclip needs to go on the mounting hole for the top tray, not on the mounting hole for the replacement stereo surround.

At this point, you can dry-mount the replacement head unit into the panel and test fit it into the dash area. Make sure all the holes line up and that it looks like it’s going to mount flush when the remaining pieces of plastic are re-attached.

Our Sony unit was wider than the Scosche panel and not quite as deep. We’re not sure whether it was Sony or Scosche who weren’t following the DIN standard, but it was a real pain. Some aftermarket stereos come with removable trim rings, but the one on the Sony seemed to be very firmly attached.

The Sony head unit is wider than the Scosche fascia panel. That means the stereo sits too far back in the housing. Time for some Dremel action!
The Sony head unit is wider than the Scosche fascia panel. That means the stereo sits too far back in the housing. Time for some Dremel action!

We had to remove around 3/16″ of plastic from the sides of the innermost edge of the lip in the Scosche panel cut-out. This was necessary for the stereo to push far enough forward to line up with the front of the panel. Luckily this also hid the fact that there was a gap at the top and bottom of the unit. We used a Dremel grinding wheel and worked very carefully, with the panel resting face down on a towel so it didn’t get scratched up.

Because we’d removed so much plastic from the panel lip, we also had to modify the brackets that hold the stereo in place so that the stereo could mount further forward.

We needed to widen the screw slots in these brackets so that the stereo could sit further forward.
We needed to widen the screw slots in these brackets so that the stereo could sit further forward.

This was a quick job with a smaller Dremel bit. It ain’t pretty, but it got the job done.

Running any additional wires you need

We added rear speakers at the same time as the aftermarket stereo. This would also be a good time to run wires for a subwoofer. If your aftermarket stereo comes with accessories like a GPS receiver or a microphone, you’ll need to run those before you reassemble the dash.

We ran a microphone to the central overhead console by threading it through the headliner, down the driver’s side A pillar, and over the disassembled dash to the area where the stereo lives.

We clipped the Sony microphone to the outside of the overhead center console, but you could remove the stock microphone and mount it inside - you can see the grille where the stock microphone lives just below where we clipped the Sony mic in place.
We clipped the Sony microphone to the outside of the overhead center console, but you could remove the stock microphone and mount it inside – you can see the grille where the stock microphone lives just below where we clipped the Sony mic in place.

The Sony cable for the microphone was just about long enough!

The microphone cable runs along the dash - we taped it down and then reinstalled the top piece of the dash.
The microphone cable runs along the dash – we taped it down and then reinstalled the top piece of the dash.

We also wanted rear speakers, so we ran a four-conductor cable from the rear of the van behind the headliner and down the driver’s side A pillar, straight down behind the fuse box in the dash, across following a main wiring harness near where the steering wheel shaft enters the firewall, and from there in to the central console and up to the rear of the stereo area. We zip-tied that cable to the existing harness in several points under the dash so it can’t come loose and interfere with the steering or foot pedals.

Other folks have wired this rear speaker cable into the back of the factory stereo harness, but we didn’t see any need. We decided instead to attach the rear speakers directly to the aftermarket stereo harness.

Wiring the harness for your replacement head unit

The basic idea here is that you need to make the correct connections between the stereo and the chunk of wires dangling inside the dash that you unplugged from the stock stereo.

The wiring you have to do will vary depending on the replacement head unit you buy and also the different adapters that are available to make it hook in to the factory harness.

There will be (at least) two parts to this. The replacement head unit will come with a wiring harness that plugs in to the back of the head unit. You’ll also have to buy a connector that mates up with the big bundle of cables with the lever that you pulled off the back of the stock stereo unit.

Again, we used Crutchfield’s configurator to suggest the stuff we needed. We ended up with the Metra/Axxess XSVI-9005-NAV harness and their ASWC-1 steering wheel control unit (Amazon links).

The stuff we used to connect the factory harness and steering wheel controls to the aftermarket stereo
The stuff we used to connect the factory harness and steering wheel controls to the aftermarket stereo

The XSVI has a socket on one end that closely resembles the socket on the back of the stock stereo. It even has the little nubs that the lever on the factory harness plug hooks in to.

The socket on the XSVI - look familiar?
The socket on the XSVI – look familiar?

The other end of it is a bundle of cables, including some with bare ends ready to connect to the aftermarket stereo harness. It also has the wiring built in to help the ASWC-1 unit act as an interpreter between the steering wheel controls in the van and the remote control plug on the back of the aftermarket stereo.

The ASWC-1 should work on most NCV3 vans with steering wheel controls, but you should check with your model before you buy it. The harness we got has some marginally different features from other Metra harnesses, but to be honest they don’t make much difference considering the feature set of the stereo we plugged in to it. So long as the harness you buy has retained accessory power (keeps the stereo’s memory), backup signal, handbrake signal, and maybe VSS (speed indication), you’re probably good to go.

Now it’s just a question of matching the cables up. The Metra harness comes with a list of which cables are which color. Your aftermarket stereo will have a similar list. Follow the lists. We printed off the appropriate page from the Sony manual and wrote the Metra harness colors next to each wire. Then we went down the page connecting each one in turn.

Although there are some standard colors, not all manufacturers use identical wires. For instance we had to connect purple/white to green/purple for the reversing signal.

Cable crimping time!
Cable crimping time!

We crimped most of the cables. We used heat-shrink wrapped crimp butt connectors. Because our factory harness didn’t have wiring for rear speakers, we didn’t crimp those to the Metra harness. Instead, we used Wago Lever Nuts on the stereo wires so that we could quickly and easily connect to the rear speaker wires we ran to the dash. The Wago nuts are awesome. They let you connect and disconnect two different thickness wires with no hassle at all.

There are a couple of other cables that you’ll need to finish your install, and they’ll depend to an extent on what features your replacement stereo unit has.

  • The factory antenna connection is a FAKRA plug. You’ll most likely need a FAKRA to Motorola adapter like this one.
  • It’s likely that your new head unit will come with a USB input on the back. If you want to retain the factory USB slot just to the left of the driver’s side central air vent, you’ll need an adapter cable. You can use a female one like this one from Ali Express, (or this one, which gives you two cables) which will attach to the end of the cable near the stereo, or you can do like we did and have a cleaner run with less connectors by grabbing a male version like this one from Amazon. Either one will take a while to reach you because it’s shipping direct from China. Ours took about 10 days. The alternative is to just use a different USB cable like this flush mount one from Amazon. You can run that to a different position on the dash – for instance one of the switch blanks.
Here's what the USB connector looks like on the back side of the socket in the dash. You can buy an adapter that will turn this into a regular USB plug for your aftermarket stereo.
Here’s what the USB connector looks like on the back side of the socket in the dash. You can buy an adapter that will turn this into a regular USB plug for your aftermarket stereo.
  • If you have the factory backup camera, it comes with a FAKRA plug on the end rather than the normal RCA plug. Yet another adapter. We used this FAKRA-to-RCA adapter from Amazon, but because it has a female RCA end we also bought a male-to-male RCA adapter for the adapter! The female RCA end is just soldered in place, so it would be easy to replace it with a male one if you wanted to instead of using extra adapters.
  • If you choose a head unit with GPS, you’ll probably also want an adapter for the GPS receiver mounted in the van’s antenna (if you have it). Only vans with the Becker navigation unit pre-installed have this GPS receiver. Other vans use an antenna that looks identical from the outside but is missing the GPS receiver and the wire from the GPS receiver to the rear of the head unit.

Once you have all the wires, plug them all in to the back of the head unit. This way, you can easily tell if you’re missing anything.

Testing the connections, putting everything back together

Now, you can offer up the head unit to the hole in the dash, connect the harness, and get ready to test all your connections!

Note: If you’re using the Metra XSVI and ASCW units, the instructions say to not plug in the ASWC until after the XSVI is initialized. Leave the wires handy so that you can easily connect the ASWC after your initial tests. You’ll need to be able to see its LED to confirm it’s working correctly.

Note: re-attach the central dash surround panel wire at this point, but leave the panel hanging.

Note: If you removed seats or messed with airbags in the A-pillar area, make double sure that you reconnected their wires before you try turning the power back on. SRS error lights are hard to reset.

It’s hard to be patient at this point, but do one last check that you re-connected everything, then re-attach the battery negative connection next to the accelerator pedal. Now put the key in the ignition and turn it to the second position.

You should get power to your stereo, and now you can test the connections by listening for output on all four channels (and the sub), by reading from a USB drive, by using the microphone, etc.

We had big issues trying to get the ASWC steering wheel control unit to work. It wouldn’t auto-detect. We updated the firmware, tried manual programming, tried cursing it, but it just wouldn’t recognize the steering wheel buttons. When we set the Sony to custom remote rather than default, we could get the call start/end buttons to work but not the volume buttons.

This is still an unresolved issue for us. We had to stop working on it for a while because the next step probably involved reprogramming it with a large hammer. When we’re calmer, we’ll try again. For now we don’t have the steering wheel controls enabled. It’s probably just our unit that’s causing the problems. We’ll update this article when we resolve it.

Update: It now works. We don’t really know which action it was that we took that finally convinced it to play nicely. Many things could just be superstitious, but we’d suggest:

  1. Handbrake on and seat belt attached (stereo won’t do some things if this isn’t the case).
  2. Front panel plugged in, even if you leave it dangling loose (it’s on the CAN bus, so it might be important to have it present).
  3. Ignition in second position, not first position (wakes up more of the van’s systems).
  4. Reset the ASWC for more than two but less than ten seconds to get the fast flashing alternating red/green lights. Now the unit is put back into uninitialized mode and will attempt to auto-detect.
  5. Don’t try manually programming the unit. Let it auto-detect, then take the key out of the ignition for several seconds (not just off, out) before re-powering everything.

We now have Vol Up and Vol Down working properly. On-Hook gives us a mute feature. Off-Hook cycles through the audio inputs. Setting the remote to “Custom” on the Sony head unit lets us then use the Sony custom remote settings to program On- and Off-Hook successfully, but Vol Up and Vol Down both take the volume in the same direction, dependent upon which was programmed most recently. We are really disinclined to mess with that stuff any more. So that’s how it’s staying. It’s a feature, not a bug.

Once you’ve got everything working, you can stuff all the wires behind the head unit, re-attach the dash panels, do a final install of the stereo/fascia panel and finally clip the central dash surround panel back in place.

Go carefully with the central dash surround replacement. You might have to temporarily loosen a couple of screws and physically push the HVAC control array up or down to make it line up properly with the holes in the central dash surround. When it’s aligned, tighten the screws back down and clip that central dash surround back in place.

Thoughts on the Sony XAV-AX100 unit

Let’s get the annoyances out of the way first. This thing takes fifteen seconds to boot up when you first start the van, and then it presents you with a safety warning that you have to “OK” before you can proceed. Every. Single. Time.

You have to dismiss this warning every time you want to use the XAV-AX100
You have to dismiss this warning every time you want to use the XAV-AX100

Luckily, if the unit was playing the radio or a connected source before you pulled the key out of the ignition, it’ll carry on playing even while the safety warning is on the screen. It’s only when you want to make a change that you have to hit the OK button. The backup camera cuts in any time you put the van in reverse (so long as the stereo is powered/powering up) so there’s no delay with seeing what’s behind you.

There’s only one digital (USB) input. If you have your phone connected, you can’t switch to playing music from a USB stick without physically disconnecting the phone and plugging the stick in. The head unit won’t work with USB hubs, so there’s no way to plug both in at the same time. There’s no Aux In jack either.

The touch screen only accepts one touch at a time, so you can’t pinch to zoom maps. That’s slightly annoying when you want to get a better overview of the area or zoom in on a specific intersection. Instead you have to use the [+] and [-] buttons on the screen. How barbaric!

Getting the van’s steering wheel controls to work with this stereo was also a massive challenge. That might be Metra’s problem, or it might be Sony’s.

Apart from those issues though, this head unit works well. It has 20W RMS per channel, which is plenty to drive the speakers we’re using. It has clear sound reproduction, a 10-band graphic equalizer, and several sound shaping/modification options.

There’s a physical volume control knob, the touch screen is particularly responsive considering it is resistive rather than capacitative, and the graphical interface is clean, consistent, and easy to navigate. It isn’t designed for boy racers who want colored LED button backlighting. It’s understated, and it gets the job done.

It’s almost three different units in one. It has three distinct personalities depending on whether you’re using it as a stock unit, using it with an Android phone, or using it with an iPhone. Even when a phone is plugged in, you can still get back to the base interface to change settings or tune in different radio stations and the difference between the interfaces isn’t too jarring.

It’s early days, but so far we’re really pleased with the upgrade.

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