With all the talk about Mini Cooper S ECU tuning and the lack of readily available information for the public leaving most owner's scratching their heads regarding "how to tune a Mini", I've decided to contribute various pieces of info to the Mini community to help owners understand how their ECU works. While much of this data might be used to help you (or your tuner) decide what to do, it's also possible it will raise many questions. I do not guarantee I will answer them all, nor will I be sitting online 24 hours a day to respond. Also I will not contribute info on how to hack someone else's tune or how to use hacked tools, but if you can figure out how to use some of the various serial com cables to read/write OBDII, or if you already have another tool that can read/write, it's possible you could start down the road of learning how to tune your own Mini. At the very least being more informed of what's involved with properly tuning a Mini if you make major mods could prove helpful to many.

I plan on throwing the data up as I have time & depending on what comes to mind as I'm writing it. If it's a bit hard to follow in the beginning I apologize in advance, but I'll clean it up & organize further as I fill in the blanks (when time allows!).

Applicable ECU types:
1) R53 with Siemens EMS 2000 (early R53's)
2) R53 TÜ with Siemens EMS 5150 (later R53's)
Both are similar enough in operation that they will be treated as one in this thread.

Table of Contents:
1) System Overview
2) Engine Operating States
3) Airflow
4) Fuel Injection
5) Ignition
6) RPM
7) Electronic Throttle & Torque Control
8) Adaptation
9) Diagnostics & OBD-II

 

Chapter 1: Overview

COMMUNICATION: OBD-II via K-line
-Initialization
-ECU ID
-Flash tool ID & unlock authorization (SAE J2186 & J2190)
-Reprogramming keys
-Erase memory
-Data transfer (read or write)
-End programming
-Check programming
-Status
-Info
-Exit & reset

ECU MEMORY: 3 parts
-Bootloader (locked)
-Operating System (w/separate checksum)
-Tune (w/separate checksum)

Monitor IO's
-Bat voltage
-Key position
-Brake switch
-Clutch switch
-O2 heaters current/resistance
-Alternator load
-AC compressor

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Chapter 2: Engine Operating States
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Chapter 3: Airflow
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Chapter 4: Fuel Injection
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Chapter 5: Ignition

Timing processing rate changes ~3000 RPM
Knock sensor output is filtered to avoid spurious noises causing retard (integrator time constant)
Knock sensor can be calibrated by the ECU for various sensitivity levels
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Chapter 6: RPM

Max engine speed: 8200 RPM
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Chapter 7: Electronic Throttle & Torque Control

Torque losses
-Supercharger
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Chapter 8: Adaptation

Pedal sensor
Ambient pressure (MAP sensor wear/sanity check)
Fuel injection / Lambda regulation
Knock sensor
MAF calculation
MAP sensors (upstream of SC and downstream of SC)
Misfire
TPS
Torque
Idle speed
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Chapter 9: Diagnosis & OBD-II

 

Reserved for future data...

 

Reserved for even more future data...

 

Final reserved spot...

 

I'd love to know how to properly tune my own car. Unfortunately I have no experience with ECU tuning, nor do I have much experience programming (just a little bit of C+ when I thought I wanted to be an engineer). Any information you are willing to give, I would thoroughly appreciate!

 

I as well am interested in this information, and personally think its a great thing to get to those of us who are willing, and able to tinker with our own tune