M44 Wiki

Volvo Motronic 4.4: Flashing, Tuning, Data-Logging, and More

Welcome to the Motronic 4.4 Wiki.  The goal of this project is to consolidate the information and resources put together by various members of the Volvo community into a singular resource, focusing on tuning and related topics of Motronic 4.4 cars, as well as the conversion of Motronic 4.3 850-series cars to Motronic 4.4.

For years the Volvo community has been held back by sub-par tuning options. Many companies offer off the shelf tunes, but these tunes are generic, poorly implemented and expensive! In the past people have blamed the stock Motronic engine management software as inadequate, unable to accommodate modifications above the stock level. The purpose of the M4.4 opensource tuning program is to provide everyone with an inexpensive and complete method to tune themselves. 

One of the greatest achievements of this project is the ability to datalog.  A factory ECU file has been modified to incorporate an additional data-logging routine. This routine enables numerous engine critical parameters to be monitored at over 18 samples a second. With this information tuning is no longer a mysterious process, throwing variables into a 'black box'.

The M4.4 ECU was used in 850s produced after 97.5. It was also used in all C/V/S70s created in 98. M4.4 is a Bosch engine management system that is an incremental upgrade from M4.3. For car equipped with M4.3, the vast majority of 850s produced before 97.5, M4.4 is a direct swap. 

With just an M4.4 ECU, a VAG-COM cable and some free software you can tune your ECU by yourself. This means you can control fueling, ignition, boost and many other factors. 

NOTE: This Wiki is far from complete, please refer to the extremely long thread on VolvoSpeed for all the information you could need.

Set up your ECU[]

Getting started: Which ECUs to get, what hardware you need, where to get the goods.

Ostrich Install: How to step up your game with an EEPROM Emulator

M4.4 A/C Conversion: If you convert from M4.3 and you want your A/C to remain functional, read this!

M4.4 Conversion Related Error Codes

TunerPro usage[]

Binaries and TunerPro files: List of current Motronic 4.4 binaries and the associated TunerPro files.

Parameters: In-depth information about each parameter available for adjustment, broken down by section like the XDF is.

ECU flashing: How to connect the ECU to flash a binary, using the flasher tool, common problems.

Tuning your car[]

Tuning: The relevant parameters to performance and how they work.

Data-logging: Logging data with TunerPro/RT and a modified binary

Modified vehicles: How to deal with upgraded components such as larger injectors, turbochargers, MAFs, etc.

Injector Constant and dead times: Tuning the injector constant and dead times

Tuning load on big turbos: A new method of mapping the turbo load rather than altering target load.

Anything else[]

Frequently asked questions (FAQ): If you have any problems, check this first!

M44 Question and Answer: Assorted curiosities answered not otherwise covered by topics.