BMW SLI – Speed Limit Info Activation on G Series G30 G01 G31: A Retrofit Experience and Remaining Challenges

For BMW owners of the G Series generation, specifically models like the G30 5 Series, G01 X3, and G31 5 Series Touring, enhancing vehicle functionality through retrofits is a popular pursuit. One sought-after feature is Speed Limit Info (SLI) activation. This article delves into the journey of enabling SLI on a G30 model, highlighting the successes and persistent challenges encountered in activating its advanced related functionalities.

Initially, the vehicle, equipped with Driving Assistant (5AS) including KAFAS4 and Dynamic Cruise Control (DCC), underwent a retrofit to enable SLI and No Passing Info (NPI). These features became operational without significant issues after removing the 8TD option and modifying the COUNTRY_SLINPI_MODE parameter in the KAFAS module. This initial success confirmed the foundational steps for SLI activation on the G series platform.

However, the journey didn’t conclude with basic SLI and NPI. The aim was to unlock the full potential of speed limit recognition by activating three additional, interconnected features:

• ISA (Intelligent Speed Assist): This function dynamically adjusts the cruise control speed based on speed limit signs detected by SLI, ensuring adherence to road regulations.
• EDP (Electronic Damper Performance or, in this context, Electronic Device for Speed ​​Prevention – Geschwindigkeitsbegrenzung): EDP extends speed limit adherence to the speed limiter function, automatically adjusting the set speed limit based on SLI readings.
• VZA (Vorausschauende Geschwindigkeitsregelung – Predictive Speed Regulation): VZA offers proactive driving assistance by warning the driver of upcoming speed limit changes. It promotes fuel-efficient driving by initiating deceleration upon approaching a reduced speed zone, minimizing the need for braking. An “Additional Sign” feature, potentially linked to VZA, is expected to display upcoming road signs in the instrument cluster (KOMBI).

Despite these features appearing to be active in the vehicle’s coding modules, they remained non-functional. To address this, a comprehensive approach was undertaken, involving generating CAFD files through Coding Verification after virtually modifying the car’s Vehicle Order (VO) list – specifically, removing 5AS and adding 5AT (Driving Assistant Plus, which includes SLI as standard). Comparing 32 CAFD files revealed approximately 90 parameter changes associated with the 5AT option.

Subsequently, parameters related to ISA, EDP, and VZA were meticulously modified. This action successfully introduced a “Speed Limit Assistance” menu within the iDrive vehicle settings. Furthermore, the standard “Limit” function evolved into “Limit Assist“. This enhancement allows the system to automatically suggest adjustments to the set speed limit based on the current road speed limit, incorporating a user-defined buffer.

Despite these advancements, a critical aspect remained stubbornly inactive: the Cruise Control “assist mode.” Ideally, the cruise control icon should transform into an “Assist + cruise logo” and proactively prompt the driver to adjust the cruise control speed according to SLI data. This crucial integration of speed limit information with cruise control failed to materialize. Extensive parameter adjustments, mirroring configurations from vehicles factory-equipped with 5AT (excluding iBrake and ACC parameters), proved unsuccessful in activating this feature.

Even activating ISA-related parameters, which were surprisingly left inactive even in the 5AT configuration, yielded no positive outcome. E-Sys, the BMW coding software, indicates that ISA might not be officially supported on the G30 platform, as illustrated below. Nevertheless, these parameters were also activated in an attempt to exhaust all possibilities.

Further investigation led to the modification of land restriction parameters, suspecting regional limitations. Default values, identical for German-market vehicles, were overwritten with values intended to disable country-specific restrictions across modules like DSC (Dynamic Stability Control) and SAS (Steering Angle Sensor). Additionally, German car options were incorporated through FDL coding, targeting modules such as DSC, SAS10, KAFAS (camera-based driver assistance system), BDC_BODY2 (Body Domain Controller), KOMBI (instrument cluster), and RS (Rain Sensor), focusing on parameters related to VFA_Funktion, SWA_Vorhanden, VFW_AVAILABLE, WWA_ENABLE, VCM_COUNTRY, LAENDERAUSFUEHRUNG, and SWW_Enable_LaneWidthAdjustmentByKAFAS.

However, despite these comprehensive coding efforts, the system persistently indicated that the function remained limited in the current country. While “Limit Assist” was successfully activated, the desired cruise control speed “assistant mode” and VZA functionalities, including the display of upcoming speed signs in white in the KOMBI and VZA-related visual warnings (gas pedal icon, arrows), remained elusive.

In conclusion, while significant progress was made in retrofitting and activating basic SLI and the enhanced “Limit Assist” feature on a BMW G30, the integration of Cruise Control Assist and VZA functionalities encountered persistent roadblocks. The suspicion of country-specific restrictions hindering full activation remains strong. Further investigation into country code limitations and alternative coding strategies is warranted to fully unlock the potential of BMW’s Speed Limit Info system on G series vehicles. Any suggestions or insights from the community would be greatly appreciated in overcoming these remaining challenges.