When converting your BMW M5 or M6 from the SMG transmission to a 6-speed manual, it’s not just about swapping out the gearbox. The interior also requires modifications to accommodate the new shifter and related components. This process ensures that the car maintains its functional and aesthetic integrity, achieving an OEM+ look while optimizing the driving experience.

Center Console Trim

One of the most noticeable changes during the manual conversion is the Center Console Trim. The original trim, designed for the SMG setup, must be replaced to accommodate the manual shifter. Whether aluminum or wood, the new trim ensures a clean, snug fit for the manual transmission and integrates seamlessly into the interior.

Along with the new center console trim, the Oddments Tray below the console is also updated. Originally, this tray featured a retractable cover that exposed only the ashtray and lighter outlet, with no other buttons inside. With the manual setup, the retractable cover is replaced by a new, fixed plastic storage tray. This new tray retains the lighter outlet and now features a holder for the EDC Button. This change removes the only ashtray from the front center console.

PRE-LCI Manual M5/M6 E6X Center Console Trim Assembly Part Number:  51168037228

Includes: PRE-LCI Manual M5/M6 E6X Oddments Tray Part Number:  51168037213

Quantity: 1

Alternatively, if you choose the LCI Manual Setup option discussed later, the ashtray is relocated to a new drawer beneath the radio. In this case, a Different Oddments Tray without the lighter outlet is required, as the outlet will now be present in the newly located drawer. It’s important to keep this in mind when planning your conversion, as this choice affects both the functional layout and the overall appearance of the center console.

LCI Manual M5/M6 E6X Center Console Trim Assembly Part Number:  51167903537

Includes: LCI Manual M5/M6 E6X Different Oddments Tray Part Number:  51168045434

Quantity: 1

M5/M6 E6X EDC Button Part Number:  61317834518

Replacement not required, use the EDC Button from the SMG 3 Shifter Surround Trim

Quantity: 1

SZM Switch Module

A crucial part of the manual conversion involves updating the SZM (SteuerZentrale Modul) switch setup. The SZM controls multiple interior functions, including seat heating, ventilation, and driving modes like MDM (M Dynamic Mode) and DTC (Dynamic Traction Control). During the conversion, we’ll relocate the MDM/DTC button from the original SMG 3 Shifter Surround Trim to the new SZM switch setup, ensuring that these controls remain easily accessible and functional.

The SZM is also responsible for managing seat functions, so we must source the right module based on your car’s specific configuration. All M5 and M6 models come with heated seats as standard, and most also feature ventilated seats. If your car has them, we’ll ensure the new SZM supports this function. For vehicles with only heated seats, we’ll opt for an SZM without ventilation controls.

Additionally, all M5 models come equipped with cornering bolsters as part of the seat setup. We’ll source the appropriate SZM from a Manual M variant to ensure full compatibility with this feature, which is essential for proper seat function.

By sourcing and installing the correct SZM, we’ll make sure that all seat functions, including MDM/DTC button relocation.

As many of the components for this swap are no longer in production, sourcing parts from a Manual S85 (used market) can be crucial for achieving the right look. Finding the right buttons, switches, and connectors ensures a factory-like finish while making sure your M5 or M6 operates exactly as BMW intended. This is an important step to maintain the car’s original functionality and preserve that OEM+ aesthetic.

PRE-LCI Manual M5/M6 E6X SZM Switch Module Part Number:  N/A

Quantity: 1

LCI Manual Setup

Faced with these challenges, we pivoted to an LCI manual conversion, which proved to be the more feasible option. While the updated trim did provide a fresh aesthetic, the main reason for this shift was the increased availability of LCI parts. Components like the ECU Switch (Electronic control unit) and its 32-pin connector (X16919), along with the left and right Switch Block Buttons and their respective 3 pin connectors (X17257 for left, X17259 for right), were significantly easier to source. This allowed us to maintain the vehicle’s functionality while completing the swap within a shorter timeframe.

That said, transitioning to LCI components comes with its own set of unique challenges. The shift isn’t just about sourcing parts—it also requires rewiring and modifying components to ensure everything fits properly. One of the major changes is the replacement of the CCC (Car Communication Computer) from the pre-LCI system with the newer CIC (Car Information Computer) in the LCI models. This swap involves updating holders and other parts such as the menu button and its wiring.

Furthermore, the MDM/DTC button functionality, needs to be relocated as part of the shift to the new Switch Block Buttons setup, adding complexity to the rewiring process.

For more details on the LCI conversion process, including the changes to the CIC, menu button, and other components, please refer to our BMW Service : Center Console Retrofit for S85 page: [click here].

The Final Touches