How to 8HP Swap an E90 + E92 — Bavarian Auto Parts
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Builds/Drivetrain/Transmission Swap

How to 8HP Swap
an E90 + E92.

A complete retrofit guide for the ZF 8HP 8-speed automatic — smoother shifts, better fuel efficiency, improved performance.

PublishedDec 30, 2025
Read~12 min
AuthorAlex Naoumov
CategoryBuild Guide
Information courtesy of Alex Naoumov / NDH Automotive
Follow Alex: Instagram Facebook Original thread

Alex did all of the hard work figuring out how to make this work without using a TCU controller. He shared this information for free with his written guide below. Be sure to show some love to Alex on Instagram and Facebook for saving you upwards of $2000 on this swap.

Notice

This blog post is provided for information purposes only and we cannot help in any way with this process. Please do not email us for troubleshooting — this guide is just for your reference.

Hello, E90 enthusiasts! This guide details the process of retrofitting an 8HP (8-speed automatic) transmission into a BMW E90, offering smoother shifts, better fuel efficiency, and improved performance compared to the 6HP (6-speed automatic). Based on my successful retrofit, this guide is tailored for the Bimmerpost community.

This guide will work for E9*, E8* and probably E7*. Just make sure your car supports EWS4. The 8HP transmission requires EWS4 for Immobilizer Serial Number (ISN) compatibility. Otherwise, make it support it. I replaced my MSV70 to MSV80 for example on my 330i. It's also possible to replace an manual or DCT to 8HP. You will need some creativity for that.

Disclaimer

This is an advanced (still in development) retrofit requiring technical expertise, specialized tools (e.g., ISTA, WinKFP), and familiarity with BMW electronics and reading schematics. Proceed at your own risk, and consult a professional if needed. Always double-check compatibility with your specific E90 model and engine. I will be offering the consult and remote coding if needed, check my company NDH Automotive (ndh.nu) -Alex Naoumov

Jump to 01 · Prerequisites 02 · Pin-out 03 · How-To 04 · Final 05 · Paddles 06 · Tuning
Chapter 01 · Before You Start

Prerequisites.

◆Tools
ISTA, WinKFP, multimeter, soldering tools, wiring harness supplies, BMW diagnostic software.
◆Skills
Knowledge of BMW electronics, wiring, and coding, ability to read and understand schematics.
◆Parts
  • 8HP gearbox (E84/E89 N20 for RWD, E7* N55 or E84 N20 for xDrive). Mechatronic from all E-gen 8HP gearboxes are interchangeable. It's also possible to buy F-gen 8HP45 and replace the mechatronic.
  • 8HP gearbox connector or complete used harness. I recommend to buy a complete used harness.
  • 8HP or DCT shifter with 8-pin connector and 6x MQS pins (1x 61136954526 and 6x 61136931880 or 6x 61130056962 when you can't crimp MQS)
  • N55 torque converter or N20 flexplate (these are 100% compatible with N52 and N55).
  • CAS3 or CAS3+ module (for EWS4 compatibility).
  • FRM3 MAX Brose (FRM3 is needed for sure, not sure if MAX is needed)
  • JBE III M (JBE III is needed for sure, not sure if MAX is needed)
  • ZF Lifeguard 8 transmission fluid or similar
  • Oil line adapter (canformance for example) or E84 oil lines
22RPD Tune — save on hardware

Running the 22RPD tune? You can skip the dupe CAS, FRM3, and JBE III entirely. Because the conversion is done in software, those modules aren't required — saving you hundreds of dollars and several wiring/coding steps below. See the tune →

Optional parts
  • Newer ABG/ACSM module (to eliminate the ghost ACSM DTC).
  • LCI paddle shifters (or resistors for non-LCI paddles).
  • Secondary CAS3+ (for XHP license on different VIN).
  • 8HP oil pan and filter
  • New gearbox bolts and other stuff you change when replacing gearbox
Chapter 02 · The Wiring

Gearbox Pin-out.

6HP Connector

16-PIN · OUTGOING
6HP gearbox connector — 16-pin pinout diagram
Swipe to see the full diagram
01EGS_MGA
02PT_CAN_L
03— unused
04EGS_DOWN
05EGS_UP
06PT_CAN_H
07S_LOCK+
08— unused
0915WUP
10P/N
11S_LOCK−
12— unused
13kl.31
14kl.30G
15ILOCK
16kl.31

GM Connector

16-PIN · OUTGOING
GM gearbox connector — 16-pin pinout diagram
Swipe to see the full diagram
01kl.30G
02kl.31
03P/N
04kl.30G
05kl.31
06EGS_UP
07EGS_MGA
08— unused
09EGS_DOWN
10PT_CAN_H
11PT_CAN_L
1215WUP
13ILOCK
14SLOCK+
15— unused
16SLOCK−

8HP Connector

14-PIN · INCOMING
8HP gearbox connector — 14-pin pinout diagram
Swipe to see the full diagram
01P/N
02— unused
03PA_BUS
04M_LIN
05PT_CAN_H
06PT_CAN_L
07— unused
08— unused
0915WUP
10WIPPE+/−
11— unused
12— unused
13kl.30G
14kl.31
Chapter 03 · The Procedure

How-To.

Step01

Prepare the car.

Convert to EWS4 if needed. Install FRM3 and JBE III. Make sure the DME is programmed with an automatic transmission mapping. This is needed so it supports torque interventions. Make sure the car is updated, especially the KOMBI so it can display the 8th gear. Make sure everything works as supposed before starting this project.

22RPD Tune — this step not needed

Skip the FRM3 and JBE III swap. With the 22RPD 8HPe swap tune, the swap is handled entirely in software — you don't need to install an FRM3, a JBE III, or a duplicate CAS. That's hundreds of dollars of modules you can leave out of your parts list.

Step02

Remove the old gearbox.

Old gearbox removal
Fig. 02 · RemovalFrame 01
Step03

Put them side by side, compare and drill one extra hole in the 8HP and elongate the other.

Side-by-side comparison
Fig. 03 · Side-by-sideFrame 02
Step04

Prepare and install the torque converter.

Either replace the flexplate to the one your 8HP came with or install the 8HP N52/N55 torque converter. In case of N54 with 8 bolt crankshaft, use N55 torque converter with N54 flexplate.

N20 flex plate will fit on (most) N4* and N5* engines. N55 torque converter will fit on all N4* and N5* flexplates. There are a lot of possibilities here.

Torque converter prep
Fig. 04 · Torque converterFrame 04
Step05

Re-pin the 6HP or GM gearbox connector to the 8HP connector under the car.

GM → 8HP

16-pin · → 14-pin · re-pin map
Swipe to see the full map
GM pin Source signal → Target signal 8HP pin
07EGS_MGA→M_LIN (re-use)04
06EGS_UP→WIPPE+/−10
10PT_CAN_H→PT_CAN_H05
11PT_CAN_L→PT_CAN_L06
1215WUP→15WUP09
01 + 04kl.30G (joined)→kl.30G13
02 + 05kl.31 (joined)→kl.3114
SignalCANPowerGroundNot used
Note · EGS_MGA wire is pinned into the 8HP M_LIN position. Parking lock SLOCK± / ILOCK handled separately — see Step 11.

6HP → 8HP

16-pin · → 14-pin · re-pin map
Swipe to see the full map
6HP pin Source signal → Target signal 8HP pin
01EGS_MGA→M_LIN (re-use)04
05EGS_UP→WIPPE+/−10
06PT_CAN_H→PT_CAN_H05
02PT_CAN_L→PT_CAN_L06
0915WUP→15WUP09
14kl.30G→kl.30G13
13 + 16kl.31 (joined)→kl.3114
SignalCANPowerGroundNot used
Note · EGS_MGA wire is pinned into the 8HP M_LIN position. Parking lock S_LOCK± / ILOCK handled separately — see Step 11.
Step06

Install new gearbox.

I recommend installing a new oil pan with filter while at it. I advice to replace all the bolts, also the torque converter ones.

New gearbox install
Fig. 06aFrame 05
New gearbox install
Fig. 06bFrame 06
Step07

Install the 8HP shifter.

Use the part numbers from above.

At shifter pin the EGS_MGA wire in the M_LIN pin on the shifter. Make new wiring harness with KL30, KL31, 15WUP, PT_CAN_H and PT_CAN_L. I pulled them from my JBE and fusebox.

8HP Shifter · Pinout

6-pin connector · wiring map
Swipe to see the full map
Shifter pin Signal Source
1KL30G←Fusebox · +12V battery
2M_LIN←Re-pin old EGS_MGA wire
3PT_CAN_L←JBE III · PT-CAN low
4PT_CAN_H←JBE III · PT-CAN high
515WUP←JBE III · Terminal 15 wake-up
6KL31←JBE III · Chassis ground
SignalCANPowerGround
Parts · 1× 61136954526 housing · 6× 61136931880 (or 61130056962) MQS pins. Pin 2 (M_LIN) re-uses the old EGS_MGA wire from the gearbox harness.
Step08

Reset the gearbox ISN so it can be used in the car.

I used this solution myself: bmw-az.info/egs/33-bmw-e70-7…eter-file.html

Step09

Install one of these zbusb files with WinKFP.

These are all the petrol 8HP45 files for the E-generation vehicles, you can experiment with them:

zbusb · WinKFPpetrol 8HP45 / E-gen
E70/E71 N55 8HP45 xDrive
* 8646496
* 8646502
* 8646500
* 8646494
* 8646498
* 8646504
* 8646492
* 8646490

X1 E84 N20 8HP45
* 7642197 (sDrive28i)
* 8626054 (sDrive16i)
* 7642191 (sDrive20i)
* 7642189 (sDrive20i)
* 8626058 (sDrive28i)
* 8626056 (sDrive18i)

X1 E84 N20 8HP45 xDrive
* 8626050 (xDrive28i)
* 7642193 (xDrive28i)
* 8626048 (xDrive20i)
* 7642195 (xDrive28i)
* 7642189 (xDrive20i)
* 8626052 (xDrive28i)

Z4 E89 N20 8HP45
* 8611957 (sDrive28i)
* 8611953 (sDrive18i)
* 8611955 (sDrive28i)
Step10

Code CAS.

It has to be fully coded as an automatic with SA205 in your VO. Also change these parameters by hand:

CAS · manual parametersset by hand
AUSWERTUNG_P_HW         → nicht_aktiv
ABZUGSPERRE_PLOCK_C6    → nicht_aktiv
Step11

Short the parking lock connector.

Short pin 1 to pin 4:

Parking lock connector
Fig. 11 · Parking lockFrame 07
Step12

Replace the oil pan and filter on the 8HP and fill the gearbox following this procedure:

aftermarket.zf.com/app/contr…505690da53.pdf

Chapter 04 · Wrap-Up

Final.

If done correctly, you can start the car now and test all the gears. Make sure oil is filled take it for a spin and fix any issues if there are. Make sure there are no rattles.

Chapter 05 · Steering Column

Paddles.

Paddle wiring for 8HP. Only LCI paddles will work, or pre-LCI paddles with resistors. So pin 22 from JBE connector X14271 goes to the EGS (as standard), pin 38 goes to ground, 31 means ground. Just reuse old 6hp egs wire. If your paddles are not original and not wired the original way, disconnect the EGS_DOWN wire and wire it to ground.

Use this schematic:

Paddle wiring schematic — JBE X14271, EGS, steering column
Paddle wiring · JBE X14271 → EGSSchematic
If paddles don't work after wiring

Try holding either paddle down for 10 seconds, then try again.

Use this guide if you need to solder the resistors: e90post.com/forums/showthread.php?t=872226

8HP Retrofit Discord (wip)

discord.gg/Y86m3qhq5f

— Written by Alex Naoumov
all credit to him
End · Build Guide · BAP-008
Chapter 06 · Software

Tuning.

Recommended tune

22RPD Custom 8HPe Swap Tune

A fully custom TCU tune built around your car — not a one-size-fits-all flash. Pick the behavior you want and we'll tune for it.

  • Optional Drag Mode with reduced torque intervention and shift pressures
  • Gear-specific shift behavior refinement
  • True manual mode
  • Gear display in D mode where supported
  • Support for naturally aspirated and forced-induction N52 setups
  • Support for N54 8HP swap applications (stock and built transmissions)
  • Support for rear end ratio changes
  • Optional kickdown activation or deactivation
Skip the hardware — save hundreds

No dupe CAS, FRM, or JBE swap required. Because the 8HP swap runs entirely in software, you can skip the FRM3 and JBE III swap steps in the guide above and leave out the duplicate CAS — saving hundreds of dollars in modules and hours of wiring and coding. Unlike some other tuning options on the market, this tune runs natively on your car: no extra hardware, no VIN spoof, no VIN gymnastics.

We offer true custom tuning. If you need a feature we don't already support, contact us and we can look into it.

Available at 22RPD View at 22RPD →
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