Suzuki GSX-S ECU Flash

Suzuki GSX-S ECU Flash

Suzuki GSX-S ECU Flash

This page is about Suzuki GSX-S ECU Flash, specifically for the Suzuki GSX-S1000 tuning but also applies to many other motorcycles and software other than just the  GSXS Woolich Flash.

See here for GSX-S750 re-flash

What is and Why Re-flash

All modern motorcycles are controlled by an ECU or computer, this controls many of the systems on the bike and particularly the Engine.

By re-flashing you are changing the parameters in the ECU such as removing restrictions, improving the fuelling or throttle response of the engine, turning off systems, such as exhaust valves and improving the performance of the motorcycle. GSX-S1000 tuning can improve the power, torque and smoothness of your motorcycle.

How to flash your Motorcycle

There are 3 ways to flash your motorcycle

  • Mail-in flash
  • Dyno Tune Flash
  • DIY Flash

Mail-in flash

This is the cheapest and easiest option, find an online company that offers mail in re-flashes and send them your ECU, it comes back after a week or so.  Just reinstall the ECU and ride.

When you send your ECU away, you must request what changes you want (i.e. what you want from a reflashed ECU) and what modifications you have made to the motorcycle.

Mail-in re-flashes are best for stock or only slightly modified bikes as the are not optimised for your particular bike

Dyno Tune Flash

With this you need to find a tuner with both a Dyno and the ability to flash your bike (many can only tune piggybacks like the PCV).

The dyno flash allows the tuner to make more changes than a mail in flash and check to see if they work on your bike by instantly being able to see what difference those changes make to the Air-Fuel Ratio and to the power or Torque the bike is producing.

A dyno flash is suitable for any bike from stock to heavily modified.

DIY Flash

A DIY Flash (or at home flash) is where you purchase the interface and the software from a company such as Woolich Racing to be able to flash your own ECU at home.

This has the advantage that you can make more changes as you have more time available (Dyno time is expensive) and can do more real life tuning in the type of riding and environment that you usually ride in, also if you make any changes to the Motorcycle you can instantly re-flash to suit those changes.

As an option many flashing kits come with a data logger and wide-band 02 sensor so you can log the Air-Fuel Ratio


Suzuki GSX-S ECU Flash

The Suzuki GSX-S1000 has a well documented fueling issue and the best way to fix it is a GSXS Woolich flash.

I decided to buy the full Woolich Racing Autotune and GSX-S Woolich Re-flash with Racetools, myself as I am always modifying my bike and like to see what effect these changes have and change the Maps accordingly.

Previously I had the FTECU flashtune software  but the flashtune software is not as versatile as the GSX-S Woolich Re-flash.

I have now got the Woolich racing bike harness and log-box to reflash the ECU

  •  Features available for Suzuki GSX-S ECU Flash from Woolich Racing
    • IAP Fuel Maps
    • TPS Fuel Maps
    • Ignition Timing Maps
    • Ignition Dwell Maps
    • Secondary Throttle Plate (STP) Opening Maps
    • Fuel Trim Maps
    • Adjust RPM Limiters
    • Adjust Idle RPM
    • Adjust Fan Temperature
    • Exhaust Valve Opening Maps
    • Enable High Speed Datalogging
    • Disable Top Speed Limiter
    • Disable Stock O2 Sensor
    • Disable Fuel Cut
    • Disable PAIR Valve
    • Disable Exhaust Valve
    • Woolich Racing AutoTune
    • Real Time Engine Data


GSXS Woolich Flash

The Woolich Racing bike harness is far more sophisticated than FTECU, there are 4 wires that connect to the ECU as well as the SDS (Suzuki Diagnostic System) connector – this allows the software to log and store all engine parameters, such as what fuel map is being used.  This makes the Autotune far more useful and easier to tune the bike.


This is all the parts supplied with the logbox, all plug and play.

GSXS Woolich FlashThe 4 wires connected too the ECU, wires come with connectors and push into empty spaces.


The SDS connector is also connected, this enables the Woolich Software to collect Engine Data such as TPS (Throttle Position Sensor), IAP (Manifold Pressure), RPM and temperatures etc.

Suzuki GSX-S ECU Flash











The logbox has a micro SD slot  to log engine/AFR data and a Micro USB connector to connect a PC to write/read from the ECU and to display engine data. 

 The logbox is permanently connected in the bike and records data every 1/100 of a second. It records the following parameters:

  • Time/Date
  • RPM
  • Throttle Position
  • Secondary Throttle Position
  • Ignition Timing
  • Intake Air Pressure
  • AFR
  • Gear Position
  • Clutch in/Out
  • Atmospheric Pressure
  • Manifold Pressure
  • PAIR on/off
  • Inlet Temperature
  • Engine Temperature

Woolich GSXS Live Data

GSXS Woolich Flash Live Data 

Woolich GSXS Flash Autotune logs
Woolich Autotune logs

The logs above are for my tuned headers but with the  new dB killer installed – as can be seen this has made the top end (throttle and/or Rpm ) too rich.


GSX-S1000 Tuning

This GSXS Woolich Flash has all resulted in a much smoother, torquier and faster bike


GSX-S1000 Tuning

Advanced Settings

Cooling fan on/off temperatures can be changed, Idle speed set and various other parameters such as fuel cut on deceleration and switching errors of for removed parts

GSXS flash advanced settings

Fan Temp

Quite self-explanatory, adjust the temperature at which the Radiator electric fan switches on and off, turning on/off earlier helps to keep the engine cooler for better running.

Idle RPM

The only correct way to set the idle speed is through the software, which controls the ISC or Idle Speed Control Valve – Stock is 1150rpm – with a freeflow exhaust or hotter cams the bike may need a higher idle speed.

Disable Stock o2 Sensor FI code

At low throttle and during cruising the bike goes into closed loop mode, this means that the 02 sensor is interrogated to find the AFR mixture and the ECU will use this information to set an AFR of around 15 – This gives great fuel economy but poor hesitant running, If any changes are made to the fuel map they will be over run by the 02 sensor.  The 02 sensor can simply be removed or disconnected (disconnecting will cause the sensor to eventually become damaged) but this will cause an FI error, use this option to turn off the error.

Disable PAIR Valve FI code

The pair valve is a system that injects fresh air into the exhaust to burn off any excess fuel on the over run that could damage the Catalytic converter.  When the exhaust is opened up (decat or silencer removal) this burning off of excess fuel bacomes very obvious as loud bangs on the over run, to stop this the PAIR valve is often blocked or disabled, again this stops the FI error code showing.

Disable Exhaust Valve FI code

The stock exhaust system has a SET valve or exhaust valve that increase the back pressure to enhance very low speed running and reduce noise.  This valve is not present on aftermarket exhausts systems and thus gives an error,  This option turns off the error.  The SET valve MAP can be adjusted in the software.

Disable Deceleration Fuel Cut

On all stock motorcycles the fuel is turned off at higher rpms during deceleration, this causes a jerky effect when you come back on the throttle as the first fuelling will just coat the walls of the inlet rather than being burnt causing the power to come on slightly delayed and with a jerk, disabling this on a GSXS Woolich Flash will cause the bike to be smother but also use more fuel.

Fast Engine Data

Fast engine data is just used for logging data, so use if you have a log box, it can cause problems with SDS and resetting ISC etc.



Neutral/Clutch RPM Limiter

This sets the rev limit when the bike is in neutral or the clutch is depressed, useful to reduce friends revving hell out of your engine when stationary

Gear RPM limiter

The standard rev limiter, stock is 11,400 rpm, mine is set at 12,900

Top Speed Limiter

Check to box to remove top speed limiter (I’m not sure if this actually does anything on the GSX-S1000 as top speed is controlled by STP opening in 6th Gear)


Fuel Tables

IAP Table

This is the fuel table for low throttle use, less than 10-12% Throttle as intake manifold pressure is more sensitive than TPS.  The numbers indicate the amount of time that the injectors are held open for.   Tune this table for low speed running and cruising.  AFR in the 14s gives the best compromise between power, smoothness and economy.

TPS Table

Only used over 10% throttle, tune this table to achieve maximum smooth power at high throttle positions and WOT.   Usually aiming for an AFR of 12.7 to 13.1 for max power

Ignition Tables



Dyno chart results

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