[FamilyMan486]

I have a 2014 VW Passat S 1.8L I recently put an rns510 in my car, coded it to the best of my knowledge and everything was happy. I "knew" I would need to eventually get a Bluetooth module some I upgraded from the basest of the base radios. Come to find out today that the Bluetooth actually works on this thing but voice control does not. Did some RNS510s have a built in Bluetooth receiver and just need a microphone, or did I do something dumb and disable my microphone when I was coding possibly?

 

[DrGER]

I believe some RNS-510s have built-in Bluetooth capability, based on the VAG part number.
Since your Passat doesn't have telephone preparation already it's unlikely a microphone is installed, let alone wired to the head unit Quadlock connector block. If a hands-free microphone was installed, it would be the overhead console:

Take a look at the Quadlock block, pins T12e/1 and 7 (connector C, below).

These go to the console microphone R38, when installed (the other parallel wiring goes to the hands-free module under the passenger seat):

Our '11 GOV was built with phone prep with the Premium 8 radio; when we replaced the RCD with an RNS-315 in 2020, I learned that the nav unit has embedded Bluetooth, though the production wire harness didn't run a microphone signal to T12e in the Quadlock block. So we coded the embedded Bluetooth off & use the separate telephone prep. Since it all works correctly, I haven't had any compelling reason to mess with it (as I still have new value-added projects to complete). --g

 

[FamilyMan486]

Okay, I'll take a look at it today. My original radio had telephone and voice commands so I'll look at the wiring diagram for the old radio as well as my quadlock connector. Also for reference, my rns510 is a revision J and was originally used in a vehicle with fender audio system

 

[DrGER]

@FamilyMan486 : Does your ODIS see Address 77 - Telephone ? You wrote above that the original radio was the base model (RCD-310?), which shouldn't have embedded BT for phones. More discussion here: VAG-COM Coding to RNS-510+9W7 Bluetooth module
--g

 

[FamilyMan486]

Yes it has channel 77 telephone. I also have the steering wheel controls with telephone and voice control buttons, I'll get a picture of my original radio when I get back to my car as well as my steering wheel

 

[FamilyMan486]

@DrGERTol so I attached pictures of my old radio, the radio I I stalled andy steering wheel radio controls. The RNS510 throws codes for no Sirius antenna (I have one on order with the green connector) and open circuit on the microphone. The only button that doesn't seem to work is the telephone button. Weirdly enough voice commands do work when my phone is paired. I'm guessing it's picking up from my phone mic maybe?

Edit: just noticed how blurry the sweeting wheel controls pic is. Center button is the phone button, very bottom is voice command button.

 

[DrGER]

Given that your ODIS sees Address 77, you should find the telephone prep mic in the overhead console. And that your old radio was an RCD-310, we know that the mic wiring isn't present at T12e, because the RCD-310 doesn't have mic input:

(T12e is the upper left connector: no Mic In+ and Mic In- at pins 1 & 7). In our Golf Variant, T12e is called T12g, and is found here for base radio builds with phone prep:

E508 is the three-button phone panel in the overhead console, R36 is the Bluetooth module J412, R38 is the overhead mic...

and here we see the connections to the RCD-310/510 at T12g (T12e above) come only from the Bluetooth module; no signal from the mic here. So, my reading here is that your RCD-310 wire harness is missing the wires at T12e/1 & 2 from the overhead mic (hence, the "Open Mic Circuit" DTC from the RNS-510). --g

 

[FamilyMan486]

Sounds like I'll be adding a couple wires to the quadlock. Luckily I enjoy doing electrical work so this will be fun. Thank you for all the info. Now to find an inexpensive backup camera haha

 

[DrGER]

@FamilyMan486 : I think VAG repair wire 000-979-009-E works with that terminal block -- one of those & a length of 22 gauge 2 conductor shielded cable should do the trick.

Re the backup camera, the RNS-510 requires RGB video from the camera in the rear lid handle. Look at this, for example: Rear Camera Harness Cable Set for VW RCD510 RNS510 Golf Tiguan Passat 56D827566A | eBay

I did one similar to this in our Golf Variant -- the hardest part (apart from undoing all the left side interior trim) was getting the video cable through the rubber boot between the body & the lid. Required coding the RNS-315 to enable "RVC (low)".

 

[DrGER]

@FamilyMan486 : I got to thinking more about this, and remembered that I was going to wire the Quadlock connector for mic input to our RNS-315 back in Fall '20 with this from Amazon: https://www.amazon.com/Adapter-Bluetooth-Microphone-Compatible-Volkswagen/dp/B0843PFRKB/
I just found the bits in my VW spares bin, and the cable alone with proper VAG connectors is worth the $15 price. Given that the RNS-315 has embedded Bluetooth, now that I'm looking at this again, I might take a look at running the cable from the Quadlock to the existing mic and giving this another go when it warms up here (effectively removing the separate BT hands-free prep module). In your case, however, you'll need to remove the two mic pins from the connector and re-insert into your existing T12x connector at the RNS end; at the mic end, you'll need to solder the wires to the existing connector. --g

 

[FamilyMan486]

This looks extremely helpful. Thank you! It'll make life much easier for me. I'm sure I've got some old VW pigtails lying around my shop somewhere that might have the size I need

 

[DrGER]

@FamilyMan486 : No need for a spare pigtail, at least on the Quadlock end.

Remove the green terminal lock:

Gently depress the retaining tabs on the terminals and slide out:

Once your female terminals are out, check the retaining tabs, then reinsert in your T12 connector, black in position 1, white in 7. --g

 

[FamilyMan486]

Oh, that's perfect then thanks!