ZF8 HP55A Transmission Swap Audi C7 S6/S7 – A Complete Guide
This guide provides a detailed and organized overview of how I replaced the factory DL501 transmission with a ZF8HP in my 2013+ Audi C7 S6/S7. As of today the car runs and drives great. The overall experience is much better and this is now what I consider the best mod I have done to the car.
Introduction
First off, I’ll say this swap has been quite a journey. I learned a lot about things I was previously unfamiliar with and gained a much deeper understanding of my car and how it works. I’m glad I took on this project because it allowed me to do something different with my build while also helping others make this swap feasible. For anyone that does it after me, it will be simple. This has been a hot topic in the community for a while, many people saying or implying that it could not be done. Not only did I set out to prove it can be done, I am here to prove that anyone can do it and it will not cost a leg or an arm. In fact, it is cheaper than replacing a DSG clutch and way cheaper than replacing a DSG. We will not get too into the WHY, but we will address the HOW.
I will not detail the removal or installation of the transmission itself—there are manuals and videos for that. Instead, I’ll cover the hardware, wiring, coding, immobilizer management, and essential tools, along with tips on where to get ODIS and how to adapt everything. I am not a mechanic.
Hardware Requirements
The hardware part of this swap is fairly straightforward compared to many other transmission swaps. Essentially, you remove S6/S7 parts and replace them with A6/A7 parts. Everything bolts right up—no custom adapters or tunnel hammering required—making it "simple" compared to other transmission swaps. Unlike nearly other ZF8 Swap, we do NOT need to use a standalone TCM such as the Turbolamik ($2500) If you see what some people go through to put ZF8 transmissions in other cars, you would agree we have it easy.
Parts List
- Transmission: ZF8HP55 (Any variant from C7/C7.5 or D4/D4.5; match your generation to minimize coding issues. My transmission A6 transmission I selected is NNT code.( It does not matter what code your DSG DL501 was, it will work on any of them)
- Rear Differential: A6 (Part Number OBC500044D)
- Rear Axles: Non-sport axles if switching to a non-sport differential (Part Number 8R0501203C) IF you already have Non-sport diff you will keep your diff and rear axles.
- Shifter Cable: 4G0713265T or 4G1713105D (with assembly)
- Transmission Mount Bracket: 40399115G
- Transmission Crossmember: 40399263G
- Torque Converter: RS7 or TDI (optional but highly recommended if you’re using an A6 transmission) ~ this will turn your A6/A7 transmission into an RS transmission
SPECIAL NOTE: TRANSCOOLER - YOU WILL NEED TO GET A TRANSCOOLER, I USED AN AFTERMARKET COOLER. YOU CANNOT USE YOUR S6/S7 TRANSMISSION COOLER THE BRACKET WILL NOT MOUNT UP. YOU CAN GET A6/A7 TRANSMISSION COOLER AND LINES.
Additional Hardware Notes
- You must swap and add a few bellhousing bolts:
- 1 × M10 100 mm bolt on the bottom where there is an extra hole.
- 2 × M10 60 mm bolts to replace where your original bolts are too short.
Take a look at this picture of DSG VS ZF8 bellhousing bolt locations for reference
ZF8
RS ZF bellhousing.png
DSG
s6c7 bellhousing dsg.png
Tools Required
- Strong Battery Charger/Maintainer (Always keep this connected while reading/flashing)
- ODIS Engineering (ODIS-E) and ODIS Service (ODIS-S), with GEKO account or dealer/shop access
- VCDS (VAG-COM) for user-friendly coding and diagnostics
- ODIS Compatible Flash Cable (for example, VNCI 6154A or Mongoose JLR Pro/Clone) (Tactrix Openport will not work)
- VAG style wire depinning tool (can be found on Amazon)
-DS1 ~ though it can be done without, it is more complicated without it
Wiring Adjustments
You must repin the DL501 transmission connector to match the ZF8HP layout. Correct pin assignment ensures the TCU can communicate properly with the transmission.
Pinout for 2013 Audi S6 Using A6/A7 Transmission Code NNT
Pin Wire Color
1 Blue/Black
2 Blue/Grey
5 Orange/Black
6 Orange/Grey
8 Green/Purple
9 Black/Purple
11 Grey/White
13 Red/Grey
14 Brown
15 Green/Yellow
Unused Wires
Brown/Grey
Red
Green
Note: Wire colors may vary by model year or region. Double-check your wiring diagram or verify continuity to confirm where each wire goes. Comment below if you need help.
Helpful Resource
YouTube Video:
https://www.youtube.com/watch?v=GRNb2nNMf0M
(This explains the transmission connector repinning process in detail.)
Immobilizer Management
These cars run on Immo V/BCM2, so you must ensure your new transmission TCU and the ECU/cluster are aligned. If your powerclass does not match, or if you have physically changed control modules (such as the transmission), you will need to adapt or disable the immobilizer:
1. Adaptation with ODIS Service
- Use ODIS-S with a valid GEKO account to adapt the TCU, immobilizer, and cluster if necessary.
2. Alternative Solutions
- An emulator, such as those from abitres or a VAG-TCU Immobilizer Emulator(physical), can bypass the immobilizer.
- Some tuners or services can do Immo-Off or IMMO TRANSFER using your DL501 EEPROM data on the AL551, although those appear less common. ODIS adaptation is generally easiest to get ahold of for the average joe.
Why Powerclass Matters
Powerclass is part of the immobilizer handshake. If the ecu powerclass and the powerclass the immo is looking for do not match, you will trip the ECU immobilizer. For example, flashing RS7 software onto an S6 ECU sets powerclass to RS7. Unless you manually match it to the S6 BCM, you will have an immobilizer conflict. If you are using my modified file, powerclass is already matched to C7 CEUC engine which is what the immo handshake is looking for.
Swap Process
1. ECU Flash
- Contact DS1 and provide your DS1 serial number, explaining that you will not change your ECU hardware but need an RS7 bin.
- DS1 will supply a stock RS7 file (e.g., 4G0906560B__0008 for a C7 RS7).
- Full Flash the stock RS7 file, then cal flash the modified RS7 bin from the attached folder. This modified file already has powerclass and IMMO settings adjusted but is otherwise stock.
- Before driving, copy over any needed (MAP SENSORS. SOI, FUEL IGNITION TABLES) tables from your old S6/S7 tune using TunerPro. Open two instances of TunerPro since the XDFs differ between files.
- Refer to other sections (e.g., VCDS) to confirm coding and clear any codes.
2. Repin the transmission connector (see Wiring Adjustments). then plug it into the transmission
- Flash the TCU with an RS6/RS7 .frf file. If you have the RS (RS6/RS7) transmission, skip this step.
- For details on obtaining ODIS-E, see the “Where to Get ODIS” section.
How To Flash Transmission with ODIS E Video
3. Adapt the Immobilizer with ODIS-S
- See “Immobilizer Management” (above) for details on matching the TCU and ECU with your cluster/BCM2.
- If you lack a local shop or dealership, refer to “Where to Get ODIS” for info on buying ODIS-S plus a server login.
- Complete the online GEKO procedures to link the new TCU and ensure no immobilizer conflicts remain.
- IF YOU ARE USING RS TRANSMISSION YOU ONLY NEED TO DO ECU FLASH AND ADAPT THE IMMOBILIZER THEN PROCEED TO THE VCDS SECTION.
- Make sure you have all of your vehicles programmed keys with you for the Immobilizer adaptation process.
How to Locate Immobilizer Adaptation and SVM in Odis Service Video
4. Scan with VCDS and Apply Correct Long Coding
- Once you have flashed and adapted components, perform an Auto-Scan (see the upcoming VCDS Section) and address any faults.
- Paste correct long coding if a module appears uninitialized (The long coding for the module is showing all 0's). When prompted, click Yes to use default values.
- Clear remaining fault codes and confirm everything is coded properly.
5. Start and Warm Up
- After major faults are cleared, start the car and let it warm to operating temperature.
- Check and correct transmission fluid levels. Refer to hardware or standard ZF8 service guides for fluid procedures.
- Perform transmission adaptations (via VCDS or ODIS) for the best shifting results.
6. TCU Tune
- After confirming the car drives well, choose a tcu tuner and flash a tcu tune that suits your modded vehicles power levels.
VCDS Section
You will use VCDS (VAG-COM) throughout the swap to verify functions, read/clear fault codes, and confirm final coding:
- Perform an Auto-Scan to detect modules and fault codes. Click "Autoscan"
- Click the "Gateway Installation List" to confirm which modules are present.
-Double click on any red or problem modules to open and review them.
*****Uninitialized Module Message
If, after flashing the ECU or TCU, VCDS indicates a module is uninitialized (all zeros showing for coding), you must re-insert or paste the proper coding:
- For ECU/TCU/ABS coding, you can try using my provided long coding if you have a C7 with air suspension and sport diff removed. Adjust if needed.
-- For non-ECU/TCU/ABS modules, use your original coding from a previous Auto-Scan.
Long Coding
Below is what worked for my C7 Audi S6 (with air suspension and no sport diff). If you see errors like “Module Incorrectly Coded,” you may need to tweak these (comment below for help):
Engine Coding: 1A2A003265460A0E1000
Auto Transmission Coding: 000001
ABS Coding: 65A64F01A665F2805B00
For the ABS module you must click Security access then wait for the bubble to pop up and enter the alternative coding password mine was S11820 then you can go to coding and paste the coding and it should accept.
Special Note:
Currently, my engine module shows the following code, which does not affect operation:
4715 - No Communication with Instrument Cluster
U0155 00 [00100111] - -
[Lost Communication With Instrument Panel Cluster (IPC) Control Module]
Not Confirmed - Tested Since Memory Clear
I plan to resolve this using SVM in ODIS-S on the Instrument and Engine modules. If that does not work, the code can be masked or disabled in the tune. It has not caused any issues or effects on driving.The instrument cluster also communicates and operates fine.
Let me clarify : If you follow this swap process correctly you will have NO swap-related error codes on the dash at all. If you do see any codes other than this one i mentioned then comment below for help. This will be a clean, proper swap.
Deleting the Sport Diff
If your original car was equipped with the sport diff but you have now installed a non-sport rear diff, you’ll need to delete the sport diff in VCDS:
Sport diff delete:
1. With no errors (sometimes errors work just depends on your VCDS) go into instruments module - coding - uncheck sport differential installed
2. Turn off car, turn back on and verify no dash errors. If so continue.
3. Go into canbus module - gateway list - remove AWD.
4. Restart car, if no dash errors continue.
5. Go into the rear of the car and remove the Fuse for ONLY the sport diff (cars might vary in fuse check diagrams). Verify no errors on dash. If so your good to remove the diff wiring/and or diff.
6. DO NOT REMOVE THE AWD MODULE OR UNPLUG
For more information, see this TGK Motorsports YouTube video discussing the sport diff delete process:
https://www.youtube.com/watch?v=T6rFej3PY9c
Enabling Paddle Shifters / Tiptronic
1. Enable Shift by Wire
- In VCDS, go to Select Control Module, then ACC/Auth, then Coding, then Long Coding Helper.
- Find Shift by Wire and check it.
- Close the Long Coding Helper. Click Do It to confirm.
2. Activate Steering Wheel Tiptronic
- In VCDS, go to Transmission, then Adaptation.
- Look for the channel Steering Wheel Tiptronic and set it to Active.
- Repeat for any other features, such as gear display, that you want active.
Make sure all three connectors on your gear selector assembly are plugged in. If you only have two connected, you are missing one.
Where to Get ODIS
- ODIS-E (Engineering) can be purchased cheaply from sites like OBDII365 (FOR FLASHING)
- ODIS-S (Service): (FOR SVM/IMMOBILIZER ADAPTATION)
- You can ask a local VW/Audi dealership or specialized VAG shop that has a GEKO account to do the required adaptations for you
- You can also purchase the software and one-time logins from various sellers on aliexpress. Some will charge around 40 dollars for ODIS-S installation plus $40-$60 dollars for a one-time server login.
- There is also another popular website for this https://www.vw-geko.com/
- Be sure to confirm that Audi is active (for immobilizer and component protection services) before paying for any logins or scheduling adaptations. You can check the status here or on their WhatsApp https://status.vw-geko.com/
Use these services at your own risk. In SOME cases, someone will remote into your computer to do the login. If you are purchasing from AliExpress you do have the ability to dispute if there is an issue. Make sure that you inquire and confirm immobilizer adaptation is active/available before purchasing.
TRANSMISSION TUNING
- I opted to tune my transmission using HPTuners, which offers a user-friendly solution for ZF8 transmissions. (This is only if you know wtf you're doing or know someone that does)
- You could also choose from one of the well-known ZF8 TCU tuners (e.g., JHM, ETSpec) to get a TCU tune.
- Ultimately, if your car is highly modified, you will need a TCU tune. The stock TCU expects certain RPM and torque limits, so exceeding them can trigger transmission codes or a “Transmission Malfunction” warning. This doesn’t harm anything; but it will make you shit bricks if you didnt know that it just means you need a TCU tune that accommodates higher rev limits and torque levels or to adjust your ecu tune accordingly. If you happen to be running below stock RS6/RS7 power levels and using stock rev limit you technically dont need a transmission tune yet.
IF YOU HAVE A C7.5 YOU CANNOT USE MY FILES
YOU WILL NEED TO SOURCE A TCU FILE THAT MATCHES THE GENERATION OF YOUR TRANSMISSION AND AN ECU FILE THAT IS C7.5 RS7 AND MODIFY THE POWERCLASS TO C7.5 S6/S7 ACCORDINGLY.
File Overview:
Download Link
MED17_1_1_ C7 RS7 STOCK 0008 IMMOFFPC41.bin - FLASH THIS TO YOUR ECU (CAL FLASH WITH DS1)
FL_4G0927158BD_1007.frf - FLASH THIS TO YOUR TCU USING ODIS-E AND YOUR ODIS COMPATIBLE CABLE (ONLY IF YOU ARE USING A6/A7 TRANSMISSION) THIS IS A C7 RS6 STOCK FILE
ZF8SWAP.TXT - THIS GUIDE IN PLAINTEXT FORMAT READ IT IF YOU GET LOST
Costs
Below is what I spent while trying to keep this swap budget-friendly. Your total may differ based on availability, upgrades, or professional assistance:
Item Cost
ZF8HP55 Transmission (NNT Code) 400
Torque Converter (RS7 or TDI) 300
A6 Shift Assembly 70
A6 Transmission Mount 60
A6 Cross Brace 100
A6 Rear Differential 160
A6 Rear Axles 100
Miscellaneous (Tools/Fluids) 1000
Total $2190
Disclaimer
The costs and methods listed here reflect my personal experience completing this swap. Your expenses and approach may vary. This guide is for informational purposes only, and you should follow all relevant safety precautions, consult with professionals where needed, and verify the compatibility of parts before undertaking any modifications. I am not responsible for any issues that may arise from performing this swap.
Dynospectrum does not endorse or support this transmission swap in any capacity. Please do not contact them for assistance with the swap. They specialize in ECU flashing software, not transmission or engine swap support. That said, they were extremely helpful with the ECU side of this project. As always, everything you do to your car is at your own risk.
Credits
This project would not have been possible without the assistance and insights from the following individuals and resources:
- QCrazy
- Audiquattro44
- PRJ
- Dynospectrum
- Christian O
- 813garage
- FE Performance
- Artemesia
- Projectlsaudia4
- Sleepertuned
- MWELL
- TGK Motorsports
- Shane Horning
- AudiNeil
Thank you to every one who helped in any way big or small. With the right tools, patience, and know-how, a ZF8 swap can transform an Audi C7 S6/S7 into a much more reliable and durable animal.
IF you appreciated this swap guide follow me on instagram @stolens6
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Originally Posted by Jake@JHM
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