Overview
Step by step technical tutorial for adding a rear fog button to BMW G30 and G01 light switches. The method replaces the switch firmware with an ECE build and refines the button mechanics so the switch sends correct LIN messages to the vehicle.



Highlights

• Clear workflow from bench setup to on car validation
• Uses the Freescale S08EL16 family switch board found in many G30 and G01 units
• Example programmer shown with USBDM and standard S19 flash
• Guidance on soft button travel to avoid sticking and repeat failures
• Bench check with BDC or FEM and a fused +12 V feed before installing
• Notes on newer G20 and G05 switches with Renesas processors

Package contents

• 9493734_NSW_NSL_SS08EL16_EPPFLASH.s19
• How to modify light switch.pdf
• IMG_5604.mov

Compatibility notes
Target switches are BMW G30 and G01 assemblies that carry a Freescale S08EL16 microcontroller. In some units a PCB trace must be opened to allow a stable read or write, then restored after programming. Mechanical differences exist across switch revisions, so the amount of trimming needed for a smooth rear fog button action can vary. For G20 and G05 switches the processor is Renesas R5F10AGEL which is write only in many workflows, and reading the original data may not be possible. Availability of functions always depends on module hardware and vehicle firmware.

Basic usage

• Read and back up the original switch firmware with a supported programmer and confirm device ID
• Load the provided S19 image and program the switch, then restore any opened trace and protect it
• Reassemble the switch and adjust the frame and button so that final travel is soft and free of binding
• Bench test the switch on a BDC or FEM with a fused power supply and confirm LIN responses
• Install the switch in the vehicle, run a functional check and clear any stored DTCs

Operating systems

• Windows 11 64 bit
• Windows 10 64 bit
• Windows 10 32 bit for legacy programmer drivers when required

Minimum system requirements

• CPU Dual core 2.0 GHz or faster
• RAM 4 GB minimum 8 GB recommended
• Storage 1 GB free for dumps and videos
• USB port for the programmer and a stable bench power source
• Administrator rights required for driver installation

Disclaimer

• Source of Files. All software and resources in this post are collected from public and open sources on the internet. We do not claim authorship or ownership.
• File Hosting. This forum does not host files. All links point to third party public cloud storage. We are not responsible for external content.
• User Responsibility. Software is provided for educational and evaluation purposes only. You use it at your own risk. Authors of the post and forum administration are not liable for any damage.