MG Flasher Custom Code Feature

Max Cooling
On-The-Fly

Switch between everyday cooling and a more aggressive cooling strategy without reflashing. On supported Custom Code configurations, Max Cooling can lower the configured target engine temperature and increase radiator fan speed when additional thermal management is needed.

New to MG Flasher? How It Works
3K CCM Menu Position
ON/OFF Live Toggle
v7.3.1 Fan Speed Control
Live Control Cooling Control
Connected
Target 110 °C
Radiator Fan OEM Control
Cooling mode Regular
Radiator flap OEM Control
Anti-Lag link Standby

Regular Cooling uses the everyday parameters configured in the MG Flasher app.

Interactive explanation only. Values shown here do not change a vehicle. Actual settings and availability depend on the installed calibration, Custom Code version, ECU software and vehicle hardware.

Two Cooling Strategies

Daily Driving.
Extra Thermal Control.

MG Flasher separates the cooling strategy into Regular Cooling and Max Cooling. Regular Cooling is intended as the everyday mode. Max Cooling can be enabled when the driver wants the DME to use the more aggressive temperature and fan settings configured during flashing.

The feature does not create additional cooling capacity by itself. Its effectiveness still depends on the condition and capability of the vehicle's radiator, cooling circuit, fan, coolant, intercooler system and airflow.

Target Temperature

Switch between the configured Regular and Max Cooling target engine temperature settings.

Radiator Fan Speed

Custom Code v7.3.1 added configurable radiator fan speed control for Max Cooling.

Radiator Flaps

On compatible Gen 2 vehicles with factory radiator flaps, enabling Max Cooling also opens the flaps.

Anti-Lag Integration

Max Cooling activates during supported Anti-Lag operation to provide the configured maximum cooling strategy.

How It Works

Regular Cooling
vs. Max Cooling.

The feature switches between two sets of cooling parameters prepared before flashing. It does not require a new flash every time the driver changes mode.

01 Everyday Mode

Regular Cooling

Uses the regular target engine temperature and standard fan behaviour configured for normal driving. This is the preferred setting for routine use.

  • Regular target engine temperature
  • Normal radiator fan strategy
  • OEM radiator flap control where applicable
02 On Demand

Max Cooling

Uses the configured Max Cooling target temperature and fan speed to request a more aggressive thermal-management strategy.

  • Lower configured target temperature
  • Higher configured radiator fan speed
  • Radiator flaps opened on compatible Gen 2 vehicles
Current Custom Code note: Radiator fan speed control was added in Custom Code v7.3.1. Intercooler coolant-volume-flow controls used by older implementations are not part of the current v7.3.1 workflow.
Flashing Configuration

Set the Cooling Behaviour
Before You Need It.

Max Cooling uses the values selected in the Custom Options workflow. Configure both the regular and maximum cooling strategy before flashing the supported map or custom calibration.

01

Select the Map

Connect the vehicle, choose the supported OTS map or custom calibration and continue to Custom Options.

02

Enable Cooling

Enable the Cooling option so the compatible Custom Code configuration can use Regular and Max Cooling settings.

03

Set Regular Cooling

Choose the target engine temperature intended for ordinary driving when Max Cooling is disabled.

04

Set Max Cooling

Configure the Max Cooling target engine temperature and radiator fan speed, then complete the flash.

Do not treat a lower fan setting as safer or quieter by default.

The MG Flasher user manual recommends 80% or more fan speed in most cases and warns that an insufficient setting can contribute to overheating and drivetrain damage.

On-The-Fly Control

Use the App.
Or Use the Steering Wheel.

The active status can be changed through Live Control, the Custom Code Menu or the compatible Custom Code Diagnostics page.

App Control

Live Control

Read the current Max Cooling status and toggle the feature ON or OFF directly from the compatible MG Flasher Live Control page.

Explore Live Control →
Diagnostics

Custom Code Diagnostics

Read the active Max Cooling value and enable or disable the feature through the compatible diagnostic menu.

Open Support Resources →
Custom Code Menu

The OEM Gauge Shows
Every CCM Step.

Max Cooling is controlled through the combined instrument-cluster logic of the OEM tachometer and Check Engine Light. The tachometer shows the selected menu position or value, while the CEL identifies the active CCM state.

3K Max Cooling in the CCM root menu
3× CEL Counted submenu confirmation
0 / 1K Disabled / Enabled inside the submenu
Temporary CCM display

The RPM values shown here are menu positions, not engine-speed activation thresholds. Outside the Custom Code Menu, normal OEM tachometer and Check Engine Light functionality is retained.

OEM instrument-cluster feedback RPM Gauge + Check Engine Light
CCM active
0 1 2 3 4 5 6 7 x1000 RPM
Root-menu position 3K Max Cooling
Check Engine LightSlow CEL blinks

The slow blink confirms that the CCM root menu is active.

Step 01 · Root menu Navigate the OEM tachometer to 3K

While the CEL blinks slowly, move through the CCM root menu until the tachometer points to 3K for Max Cooling.

Interface demonstration only. Exact button inputs depend on the configured UniRocker or RockerCombo setup. Vehicle support depends on ECU software, installed Custom Code and the options enabled during flashing.

Responsible Use

More Cooling Demand
Does Not Replace Maintenance.

Max Cooling changes the requested strategy. It cannot correct a weak battery, low coolant, air in the system, a failing pump, damaged radiator, blocked airflow or other mechanical faults.

01

Regular Mode First

Use Regular Cooling for daily driving unless there is a reason to request the more aggressive configured strategy.

02

Monitor Temperatures

Use supported logging and diagnostics to confirm that the cooling system is responding as expected.

03

Maintain the System

Cooling performance depends on healthy hardware, correct coolant level, airflow and proper system operation.

04

Use Valid Settings

Do not copy temperature or fan values from another vehicle without confirming that they suit the exact platform and calibration.

Compatibility

Availability Depends
on the Installed Configuration.

Max Cooling support can vary by engine platform, ECU software, Custom Code version, vehicle hardware, calibration and the options enabled during flashing.

01

Supported ECU Software

The ECU software must support a compatible Custom Code version and Max Cooling implementation.

02

Cooling Enabled

The Cooling option and required settings must be enabled and configured during the flash workflow.

03

Vehicle Hardware

Fan-speed and radiator-flap behaviour depend on the hardware and control modules installed in the vehicle.

04

Control Method

Live Control, CCM and Diagnostics availability can differ according to app and Custom Code version.

FAQ

Max Cooling
Frequently Asked Questions.

Common questions about Max Cooling On-The-Fly, fan control, Custom Code Menu access and compatibility.

What does Max Cooling On-The-Fly do?

On supported configurations, it switches the DME from the regular cooling parameters to the configured Max Cooling target engine temperature and radiator fan-speed settings without requiring another flash.

Does Max Cooling make the engine run at one fixed temperature?

No. The configured target is part of the thermal-management strategy. Actual temperature still changes with load, ambient conditions, airflow, cooling-system capacity and vehicle operation.

Can Max Cooling be enabled from the app?

Yes, where Live Control is supported. The compatible app page can read the current status and toggle Max Cooling ON or OFF.

What does 3K RPM mean in the Custom Code Menu?

It identifies the Max Cooling submenu position. It is not a real engine-speed threshold for activating the feature.

What do 0 RPM and 1K RPM mean inside the submenu?

Inside the Max Cooling submenu, 0 RPM represents Disabled and 1000 RPM represents Enabled.

Does Max Cooling open the radiator flaps?

On compatible Gen 2 vehicles equipped with the required factory radiator-flap hardware, the MG Flasher documentation states that enabling Max Cooling also opens the flaps.

Does Max Cooling activate with Anti-Lag?

The current MG Flasher documentation states that Max Cooling activates during supported Anti-Lag operation to provide maximum configured cooling capability.

What fan speed should I use?

The MG Flasher user manual recommends 80% or more in most cases and warns against setting the fan speed too low. The appropriate value still needs to suit the exact vehicle and calibration.

Does Max Cooling repair an overheating vehicle?

No. It changes the requested control strategy but cannot repair mechanical faults, low coolant, poor airflow, a failing pump, fan, thermostat or radiator problem.

Ready to Check Your Setup?

Use Max Cooling
with MG Flasher.

Find your supported engine, verify ECU compatibility and download the app before purchasing or flashing.

Privacy Overview
MG Flasher

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.

Strictly Necessary Cookies

Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.

Analytics

This website uses Google Analytics to collect anonymous information such as the number of visitors to the site, and the most popular pages.

Keeping this cookie enabled helps us to improve our website.