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DCC Retrofit

Cuzoe

Autocross Newbie
Location
Los Angeles
So I think is the right forum for this topic. I am in the process of the retrofitting DCC to my 2015 TDI. I'll chronicle my adventures along the way, including part numbers, hiccups, etc. in subsequent posts. As the project continues the first post will be updated to include relevant information for later reference.

Note: The NAR Mk7 TDI has torsion beam rear suspension and comes with 50mm diameter front struts. This will add some complication to the retrofit in the way of additional parts that are not directly related to DCC but will be required in my case. It may also change the part numbers for some parts. But I'll look into that later on, likely after I get everything installed on my car. I will list the current MSRP's of major components for reference.

Required parts:
Active Suspension Control Module (J250): 5Q0 907 376 B - $387
Active Suspension Control Module Bracket: 5G0 907 324 - $23
* Module is installed behind hatch trim, driver side, aft of the wheel arch
Accelerometers (3 needed; G341, G342, G699): 5Q0 907 651 - $170/ea
* Under hood, top of each strut tower (need to confirm but I believe under the rain tray), and the third in the car at the top of the rear driver side wheel arch (near the control module)

Rear Left Level Sensor (G76): 5Q0 512 521 E - $252
- Mounting screw: N10546403
- Rivnut: N91200701
* The diagram suggest a few more screws will be needed to mount this, I'll add those part numbers when I find them
* If you have a TDI (or possibly any Mk7 Golf) with lighting package I think you already have this sensor
* Might be a different part number for IRS cars (all the NAR Mk7 Golf/Variants except the TDI)
* There is no Rear Right sensor

Front Left Level Sensor (G78): 5Q0 412 521 C - $252
Front Right Level Sensor (G289): 5Q0 412 522 C - $252
- Mounting Nut (2ea): N10205802
- Mounting Bold (2ea): N10653201
* Could not find these sensors on parts.vw.com diagrams but they are here, items 20, 21, 22
* PR Code is 2H4 - Driving Profile Selection and hydraulic damper control... I interpret this as DCC
* I can only find them on Audi parts websites but fitment shows 2015-2020 Audi A3/S3 which is MQB

Strut/Shock Part Numbers
* to be added soon

Front Axle, Steering Knuckle, and Bearing Part Numbers
* to be added soon, not necessary if you drive a GTI, but Golf/TDI have 50mm struts and to my knowledge DCC struts only come in 55mm


Here's a system overlay picture (oddly enough it shows a GTI front but with the torsion beam rear suspension):
Golf 7 DCC.jpg
 

simaservis1108

Go Kart Newbie
Location
Serbia,Belgrade
Car(s)
Seat Leon 5F FR
Then after all that has been fitted,you come to one obstacle that is almost impossible to do.
Parametrization of the DCC module.

All this I went through when I did DCC retrofit on RS3 Audi.
Its doable,but programming it is the hardest part.
 

Cuzoe

Autocross Newbie
Location
Los Angeles
That would be the hardest part for me, personally to do... but I'm happy to pay to have that done. Finding the part numbers, sourcing parts (at a subjectively reasonable cost), building the harness (finding connector, pin or repair wire part numbers), installing the harness (whether built or bought) is much harder than finding someone to do the coding, in my opinion.
 

UA TDI

Passed Driver's Ed
Location
Central PA
Car(s)
MK7 GTI
Interested in where this goes. Love my Sport trim GTI but always thought the DCC would be amazing for daily driving.
 

Cuzoe

Autocross Newbie
Location
Los Angeles
The following post only applies if you drive a Golf/GSW TDI or a Golf TSI (GSW excluded). I'm only talking NAR. I guess it should also be said that anyone doing this should double check my research as I will not be able to reimburse for any parts that did not work for you (or that you did not need).

Left Steering Knuckle: 5Q0 407 253 A - $465
Right Steering Knuckle: 5Q0 407 254 A - $465
- Bearing/Hub Assembly: 8S0 498 625 A (or 8V0 498 625 A) - $292
* Note that the bearing/hub assembly supersedes the bearing/hub assembly part number from the TDI, so you can probably switch them over
* Also the 8V0 bearing is specified as an Audi bearing but parts.vw.com shows the 8S0 as the superseding part number so it may be the only thing available

For those that want some negative camber, about -1°, Clubsport S Knuckles
Left: 5Q0 407 254 E - $465
Right: 5Q0 407 253 E - $465

The MSRP of both the standard GTI/R/etc knuckles and the Clubsport S knuckles is the same, but both can be found for less. Standard ones are cheaper of course, I've seen them right around $300 new. New Clubsport S knuckles can be sourced from cars245, e-acca, or eBay (but shipping from the EU so may as well use one of the two vendors mentioned previously). I usually see them around $350 depending on exchange rate, plus shipping.

Used knuckles (generally with attached hub/bearing assemblies) are available from wreckers of course. I paid $275 shipped for a pair. Not knowing the mileage of the donor car I will likely replace the bearings (with mine or with new, to be determined).

I have not included front axles part numbers as I'm reasonably confident that your existing axles will work. I'm also not sure if there are axle differences between PP and non-PP GTI's (anyone with that info, please post it) and parts.vw.com is somewhat vague when it comes to certain parts. This info will be added to the first post at some point, maybe tomorrow... hopefully with shock/strut part numbers as well.
 

Cuzoe

Autocross Newbie
Location
Los Angeles
So I got the DCC harness in. In the course of doing my normal inspection of the harness for general quality and to see how/if the colors match the Erwin drawings I found that this harness was built with the expectation that the vehicle already has the rear left level sensor. This sensor would be installed on cars with self-leveling headlights.
DCC Harness.jpg


In retrospect maybe I could have deduced as much based on the attached wiring snippet. Module J250 is the DCC controller and G76 is the rear level sensor. The splice points, W23, W24 and W75 are "Sensor Connection 1, 2 and 3" respectively. A search of the full wiring diagram shows G76 on the headlight range control drawing.
DCC Wiring Snip.JPG

4 pin connector for the level sensor: 4B0 973 712 A - $15
Boot and repair wires for this connector: unknown, tbd

Pretty common on eBay, just search "VW 4 pin pigtail" or similar. Also available on Amazon with 4 wires (with the properly sealed pins), would just need to put a heat shrink boot on it. Presumably these Amazon ones won't have the VW/Audio logo molding but I'm sure they work just fine, and you get an extra wire in case you screw something up, haha.

Additional part numbers should someone want to build their own harness entirely...
47 Pin DCC Module Connector: 7L0 973 047 - $55 (will come without wires/pins)
2 Pin Connectors (7 needed): 4F0 973 702 - can't find these from an official place but seem to be around $10 with pigtails
4 Pin Connectors (3 needed): 4B0 973 712 A - $15

More to come, maybe when I get home tonight.
 

AWD4416

Ready to race!
Location
Texas
This is awesome! When I got my GTI i could have swore it had DCC but what it had was the emergency brake assist. I was so bummed but so far I retrofited LED headlights, ACC, the factory alarm with sensor, and the driver assist camera. Really DCC would be the last thing I would retrofit as all my retrofits are based of comfort. I totally should should have purchased the top of the line GTI but it was out of reach as i took delivery of it 😒. Really looking forward to your journey as I'm looking at pulling the trigger on this but my take is put all the electronics and go with Billstein shocks/struts.

Do you know if the GTI would require new springs or the factory one compatible with the DCC equipment? I'm looking forward to ultimate comfort, would like a mild drop but function over form.
 

replicate

Go Kart Newbie
Location
Downunder
Interesting. I wonder how we could learn how to disable DCC without buying a canceller from this process. (For fitting coilovers)
There are steps to do it but there is an issue that I don’t think anyone has solved in relation to the rear level sensor.

Incomplete steps
Step Uno: Unplug Fuse 13 in fuse holder C located behind the flip-down compartment to the left of the steering wheel (LHD).

Step Dos: Uncheck Susp.Electronics from the CAN-Gateway.

Step Tres: Uncheck Bit 7 in Byte 27 of the ABS-module to allow the ESP to function.
 

ZERO815

Go Kart Champion
Location
Köln Germany
Car(s)
NA '17 GTI SE DSG
There are some guys in Germany w/ retrofitted DCC to Octavias, Leon and Golf. DCC_retrofit_Skoda_Octavia Unfortunately everthing in German...

What is the disable-issue about the rear level sensor? To my understanding G76 is either connected to J250 (DCC ECU) or J745 (Headlight Range ECU). If vehicle is equipped w/ DCC J745 pulls the rear left leveling data from CAN. After disableing DCC I guess you have to connect G76 to J745 directly to get rid of a leveling sensor fault.
 

replicate

Go Kart Newbie
Location
Downunder
There are some guys in Germany w/ retrofitted DCC to Octavias, Leon and Golf. DCC_retrofit_Skoda_Octavia Unfortunately everthing in German...

What is the disable-issue about the rear level sensor? To my understanding G76 is either connected to J250 (DCC ECU) or J745 (Headlight Range ECU). If vehicle is equipped w/ DCC J745 pulls the rear left leveling data from CAN. After disableing DCC I guess you have to connect G76 to J745 directly to get rid of a leveling sensor fault.
If you try to disable DCC using the method I posted, taken from the rosstech site here. There may be other issues too. I’ve been trying to find if anyone had successfully coded out DCC without needing to fit cancellers and not having any errors.
 

doctor

Passed Driver's Ed
Location
VAG
Car(s)
.
Then after all that has been fitted,you come to one obstacle that is almost impossible to do.
Parametrization of the DCC module.

All this I went through when I did DCC retrofit on RS3 Audi.
Its doable,but programming it is the hardest part.
That's easy step after all.
 

Cuzoe

Autocross Newbie
Location
Los Angeles
There are some guys in Germany w/ retrofitted DCC to Octavias, Leon and Golf. DCC_retrofit_Skoda_Octavia Unfortunately everthing in German...

What is the disable-issue about the rear level sensor? To my understanding G76 is either connected to J250 (DCC ECU) or J745 (Headlight Range ECU). If vehicle is equipped w/ DCC J745 pulls the rear left leveling data from CAN. After disableing DCC I guess you have to connect G76 to J745 directly to get rid of a leveling sensor fault.

Continuing today with wiring checks of the DCC harness and the "missing plug" for G76 (left rear level sensor) @ZERO815 is exactly right. This breakout (in this harness) for this sensor is wired up to the front of the car and would be long enough to reach the headlight range ECU. The expectation is that you would de-pin the three wires for G76 here and wire them directly to the DCC ECU.
IMG_20201004_172105.jpg


My solution for that will be partial custom wire harness coming from G76, tessa taped and zip tied to the harness that goes to the left rear shock. I will unwrap enough the harness near the DCC ECU connector to find the three G76 wires. I'll cut them here and splice my wires in. Then I'll cap/stow (on both sides) the wiring for G76 that came in the harness.
 
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Cuzoe

Autocross Newbie
Location
Los Angeles
... That's done, laser stamped some wires and dressed them up, just waiting on the 4 pin pigtail from eBay.
IMG_20201004_183357.jpg

IMG_20201004_202129.jpg
 
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AWD4416

Ready to race!
Location
Texas
@Cuzoe Do you know if DCC has FEC or SWAP codes? I'm starting my journey, put a few things on order but started to wonder if I'm going to need special codes to enable any of this.
 
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