MS43X Custom Firmware

MS43X is a custom firmware that's based on MS430069, but with several new and some extended functions. Summing up it can be seen as the successor of patchlists for 430069 and will include all future feature updates. We decided to go this route because of the raising difficulty of adding new features without butchering existing ones and optimization of execution time.

Overview

All the basics and resources will be explained here. For a more detailed explaination check out the sub views.

Downloads

The main difference to existing firmwares is that we will no longer be publishing patchlists, because that left room for problems and lead to frustrating results in the past when used incorrectly. Every new MS43X firmware release will get new definition files that will come bundled with it.

Firmware Files

• E36/7 Z3-series
  • soon
• E39 5-series
  • soon
• E46 3-series
  • soon
• E53 X5-series
  • soon

Definition Files

• MS43X001 Partial [64kb] || MS43X001 Full [512kb]
• Siemens_MS43_MS43X001_Logging_File.adx

We will only reference the newest version here, for legacy versions check the download archive: MS43X Firmware Archive

Changelog

Make sure to check out the latest version.

Latest Version: MS43X0001 (January 2024)

MS43X001

• Initial release firmware

Designated I/O

• Secondary Air Mass Air Flow Sensor (SA_MAF) - manifold air pressure sensor input

Main Features

Load Acquisition

One of the most impacting changes with MS43X is the completely overhauled engine load acquisition. We changed the complicated engine load calculation used in MS43 to aspeed density or volumetric efficiency (VE) based system. This is more commonly used with standalone ECUs and can be tuned just like that. That means you can now decide between a MAF sensor, a MAP sensor or Alpha/N as your primary load input.

• c_conf_load - Load input configuration (0: MAP sensor, 1: MAF sensor, 2: Alpha/N)
• c_eng_disp - Engine displacement in cubic decimeters

MAF and MAP sensors utilize different 0-5V inputs on the ECU, so you can define different threasholds for the signal error detection.

In theory you can even connect a MAF and a MAP sensor and then switch by just changing c_conf_load in the calibration file.

MAP Sensor Variables

• c_map_diag_ini - Initializations value for manifold air pressure sensor diagnostics
• c_map_min_diag - Minimum manifold air pressure for short to ground diagnostics
• c_map_max_diag - Maximum manifold air pressure for short to positive diagnostics

Volumetric Efficiency

Something that is different from the usual speed density integration in standalones is that instead of a single VE table we have eight. This is necessary because the VANOS can influence engine efficiency based on valve overlap.

New Features

Make sure to check the minimum version included in the function sub page.

Boost Control

Minimum firmware version: MS43X001

Flex Fuel

Minimum firmware version: MS43X001

Sensor Diagnostics:

• c_ff_v_min_diag - Minimum flex fuel sensor voltage for short to ground diagnostics
• c_ff_v_max_diag - Maximum flex fuel sensor voltage for short to positive diagnostics

Substitute values in case of sensor fault

• c_ff_ti_diag_sub - Flex fuel blending factor substitute in case of sensor fault - Injection
• c_ff_iga_diag_sub - Flex fuel blending factor substitute in case of sensor fault - Ignition
• c_ff_bc_diag_sub - Flex fuel blending factor substitute in case of sensor fault - Boost controller

Blending factors depending on flex fuel input voltage

• ip_fac_ff_ti__v_ff - Flex fuel blending factor - Injection
• ip_fac_ff_iga__v_ff - Flex fuel blending factor - Ignition
• ip_fac_ff_bc__v_ff - Flex fuel blending factor - Boost controller

Launch Control

Minimum firmware version: MS43X001

Knock Light

Minimum firmware version: MS43X001

M Cluster Support

Minimum firmware version: MS43X001