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Discussion Starter · #1 ·
Starting this thread in the hope that others weight-in on the evolving topic of upgrading the Audio30/40 system in the new 2021 Metris. The main issue I have at the moment is that I need an accurate diagram for the Audio30 pin-outs on the main stereo harness plug. All the other connectors on the HU are Fakra connectors for antennas, camera, etc. The best solution I have found for maintaining the steering wheel controls and the peripherals attached via the Fakra connectors is the RPA4.2-MB11from PAC (Pacific Accessory Corporation). This product is designed to support after-market stereo installs with the stock MB harness on Sprinters up through 2019. The 2021 Metris (and presumably the Sprinter) have slightly different pin-outs, so I am working with PAC's customer support team to figure out the pin-out mappings to their harness. So far, they have been awesome to work with. NOTE: this means I will need to move the pins around in the plastic connector of the PAC harness to match the Metris harness. I strongly recommend to anyone wanting to do this, that they purchase the handy tool that makes this easy. They are available from many online sources for less than $10. The important thing is that the PAC harness has to map it's CAN-bus inputs to the CAN-bus outputs in the Metris harness for the steering wheel controls to work. Once I have that mapped, I can then map the other wires in the main plug that relate to the stereo system. The Fakra plugs for the back-up camera, the Sirius XM antenna, the Radio antenna and the GPS Navigation can be acquired on Amazon in all the different connections needed to connect to the PAC unit. Once it's all sorted, PAC will likely release an updated harness for 2021 Metris and Sprinters.

I will update this thread as I make progress.
 

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Discussion Starter · #3 ·
Where are you located?

Is the connector and pin count the same?
I’m in Seattle. Not sure w/o going to take a look, but I think the pin counts are the same and it is only a matter of position. The plug and receptacle have been the same for years as was explained by the PAC support team. It’s just a matter of how many pin locations are used, in what position the pins are placed and the color of wires. That changed in 2020. I think the other changes related to the Audio30 and 40 radios are implemented through the Fakra connections, e.g. SiriusXM and Garmin nav.
 

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If you just want to identify the canbus high and low it should be easy enough with a meter.

Maybe one of the guys with the tech doc access can find a diagram for the connector on the 21. If you can buy the access on the gray market on ebay. It's like 10-20 bucks.
 

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Discussion Starter · #5 ·
If you just want to identify the canbus high and low it should be easy enough with a meter.

Maybe one of the guys with the tech doc access can find a diagram for the connector on the 21. If you can buy the access on the gray market on ebay. It's like 10-20 bucks.
It would be great if someone can send me the 2021 Metris Audio30/40 wiring diagram. I’ll also check eBay. I signed up for the MB Service Portal, but it is pretty pricey. I need to get all my doc needs written down before I pay for a 24hr access window 🥴
 

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Discussion Starter · #7 ·
What makes you believe the pinouts have changed?
Fair question. My understanding is that the Sprinter changed in 2020 and that the Metris likely did as well. I don't actually know for sure. I still need a newer wiring diagram to confirm. I will then post here if there are any differences. The PAC connector is for a 2016-2019 Sprinter, but is the only harness that I could find that was close.
 

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Discussion Starter · #11 ·
I personally would assume it has not changed and try it.
The challenge is that the PAC harness does not match with the Metris harness. I have PAC documentation for it’s wiring. I need the Metris wiring diagram to match them. Some colors are the same and others aren’t. Some are in the same location and others aren’t. If nobody has a Metris wiring diagram, I’ll have to use a multi-meter and process of elimination.
 

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Discussion Starter · #13 ·
Here are some pictures. Metris01 shows my stock harness receptacle. Metris02 and Metris 03 show the wires on this harness. PAC01 shows the PAC harness receptacle I need to map to my stock harness receptacle in Metris01. PAC02-PAC04 show the PAC harness wires and the PAC_Metris_Alignment shows the two harness receptacles aligned side by side. I just need to figure out what the wires on my stock harness receptacle are, e.g. CAN-bus, power, ACC, ground, etc.

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I think I see where some of the pins on the male and female side might not connect. Like there is a pin and no receptacle. That doesn't mean it's wrong though. Easy enough to see on the PAC wiring document the wire colors and their meaning so you can at least see what is not literally connecting. Maybe you don't need them or maybe your van didn't have those features. Not sure.

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Discussion Starter · #17 ·
Good question. There are three wires in the PAC harness that are not identiofied in the sheet above. I will be talking to the support guys about that, but step one is identifying the CAN-bus wires on my Metris harness. PAC support knew which ones were my power and ground and I know which ones are the speaker outs, so process of elimination will help figure out the rest. I have the premium audio40 HU with SiriusXM, NAV and Carplay. I do not have rear speakers.

To be clear - the PAC harness is for a Sprinter, so the fact that pins are in different places is expected. The PAC harness has the wires I need to hook up the steering controls (CAN-bus) and the stereo. The goal is to match the wires on both and move that PAC pins to match.
 

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Yes, the harness is shared with Sprinter and Metris as shown on their website.


On that harness one end of the Blue and White wires is on the body connector. Where does it lead? Does it go to a stripped connector or does it lead to another type of connector.

I would assume the pink canbus wires are connecting to the correct plug connectors. If you want to check them it's simple with a meter. They have resistance on them so you can identify High and Low.

Do you have steering wheel controls? The Premium wheel?

Lack of the rear speakers accounts for the 4 missing female connections on the 8 pin portion of the connector.
 

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Discussion Starter · #19 ·
The blu/wht terminates to a stripped end and is one of three on the PAC connector that are not identified in the vehicle connector table of their documentation.
I think the CAN wires on the Metris are one these on the right side of the photo, likely the two green ones. How do I test with a multi-meter?

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I think they are the brown ones next to the yellow ones. They would mate up to the pink ones on the pac connector that indicate canbus input.

With a meter ground to chasis and touch the female socket. Note the voltage. I'm not sure if mb is 12v on that bus or 5v, but you will find out. High might be close to 11v. Low could be near 1v. The spread can be more narrow. Try this with the key out.
 
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