OEM Control
Return radiator flap control to the DME. The ECU determines flap position using the original vehicle logic and current operating conditions.
Recommended for normal driving
MG Flasher Custom Code FeatureBMW Radiator
BMW Radiator
Flap Control
Control supported factory radiator flaps directly from the MG Flasher app. Choose OEM, Closed or Open on compatible G-Series vehicles, while Max Cooling and Anti-Lag can open the flaps automatically when additional airflow is needed.
Cooling performance setup? Explore Max Cooling →
OverviewManage Airflow
Manage Airflow
Through the Cooling Pack.
Many compatible G-Chassis BMWs use electronically controlled radiator flaps. Under normal operation, the factory ECU opens or closes them according to cooling demand, aerodynamic efficiency and operating conditions.
MG Flasher adds supported app-based control, allowing the driver or technician to temporarily select OEM, Closed or Open. Manual Open can increase airflow during demanding conditions, while OEM returns control to the original DME strategy.
Simple Definition
App-based control of factory electronic radiator flaps
OEMFactory strategy
→OpenMore airflow
→SleepTemporary state resets
Control States
OEM. Closed. Open.
Choose the state that matches the current operating need on a compatible vehicle.
Closed
Force supported radiator flaps closed temporarily. This state should be used only when there is a clear reason and the cooling system is being monitored.
Use only when appropriate
Open
Open supported radiator flaps to increase airflow through the radiator and cooling stack, helping reduce heat buildup during demanding use.
Maximum available airflow
How It Is ControlledApp Control.
App Control.
No CCM Position.
Radiator Flap Control is managed through the MG Flasher app on compatible vehicles. It is not assigned to the steering-wheel Custom Code Menu, so the OEM tachometer and Check Engine Light are not used to navigate this feature.
Supported Control PathsLive Control or
Live Control or
Custom Code Diagnostics
Both app interfaces can work with the same three supported states: OEM, Closed and Open. The available controls depend on the connected vehicle, factory radiator-flap hardware, ECU software and installed Custom Code.
Live Control
Change the flap state while connected to the vehicle
Diagnostics
Read the active state and request OEM, Closed or Open
No CCM
No tachometer position and no counted CEL confirmation
Temporary manual state
Manual Open or Closed is not stored in EEPROM. The selected state is cleared when the ECU resets or the vehicle goes to sleep.
MG Flasher App
Radiator Flap
Compatible vehicle
Selected state
OEM
Factory ECU strategy
Control source
APP
OEM
Factory control
Closed
Manual request
Open
Maximum airflow
Cooling-pack airflow
ECU controlled
Custom Code Menu
Not available for Radiator Flap
There is no RPM-gauge submenu or CEL blink sequence for this feature.
Static explanation only. Exact controls and automatic behaviour depend on the connected G-Series vehicle, factory hardware, ECU software and Custom Code configuration.
Automatic IntegrationWorks with Max Cooling
Works with Max Cooling
and Anti-Lag.
On compatible vehicles, radiator flaps can open automatically when Max Cooling is active or when supported Anti-Lag is engaged. This provides additional airflow without requiring the user to select Open manually first.
Automatic operation depends on the exact vehicle, factory hardware and installed Custom Code. The MG Flasher app should be used to confirm which controls are available for the connected car.
Radiator flaps open automatically on supported configurations.
View Max Cooling →Radiator flaps can open automatically to support cooling demand.
View Anti-Lag →
How to Use
Four Simple Steps.
Use a compatible connection and confirm support before changing the factory flap state.
Connect
Connect to the Vehicle
Connect the MG Flasher app to the supported BMW through a compatible ENET connection.
Open Controls
Navigate to Live Control or Diagnostics
Open the available radiator-flap control on the connected vehicle.
Select
Choose OEM, Closed or Open
Select the state required for the current use case and confirm the change in the app.
Monitor
Watch Vehicle Temperatures
Use supported live data or datalogging to evaluate cooling-system behaviour where appropriate.
Temporary OverrideThe Manual State
The Manual State
Is Not Stored in EEPROM.
The manual Open or Closed value applies until the ECU resets or the vehicle goes to sleep. After that, the flap system returns to its normal operating behaviour.
This differs from supported On-The-Fly settings such as map slots or Max Cooling status that may be preserved through EEPROM Storage.
Control Lifecycle
1
Select a stateOEM, Closed or Open in the app
2
Temporary overrideThe DME uses the selected state
3
ECU reset or sleepThe temporary selection is cleared
Compatibility
Factory Electronic Flaps Required.
Support depends on the complete vehicle and ECU configuration, not only the model name.
Compatible G-Series / Gxx BMW
The feature is intended for supported G-Chassis vehicles with electronically controlled radiator flaps.
Radiator Flaps Installed
The car must contain the factory electronic flap system. MG Flasher does not add missing hardware.
Compatible Aurix-Based ECU
Live Control documentation identifies the function as available only on compatible Aurix-based ECUs.
Compatible Custom Code
The installed ECU software and Custom Code version must expose the radiator-flap controls in the app.
Documented examples include:
BMW G20 3 Series, G22/G23 4 Series, G30 5 Series and other compatible G-Chassis models with factory electronic radiator flaps.
Important Notes
OEM Control Is the Normal Default.
Manual flap control should be used deliberately and only when the operating reason is understood.
Use OEM for Daily Driving
The factory strategy balances cooling demand, aerodynamic efficiency and warm-up behaviour.
Open for Cooling Demand
Manual Open may help airflow during track use, testing or other high-temperature conditions.
Monitor the Vehicle
Manual changes do not replace proper maintenance, cooling-system health or responsible logging.
FAQ
Radiator Flap Control FAQ.
Common questions about compatibility, control methods and automatic operation.
What does Radiator Flap Control do?
It allows compatible MG Flasher users to temporarily select OEM, Closed or Open for factory electronic radiator flaps on supported vehicles.
Which cars support this feature?
It is intended for compatible G-Series / Gxx BMWs with factory electronic radiator flaps and supported ECU and Custom Code configurations.
Can I use Radiator Flap Control through the Custom Code Menu?
No. Current documentation states that radiator-flap control is not available through the steering-wheel Custom Code Menu.
Can I control the flaps through Live Control?
Yes, on compatible setups Live Control provides OEM, Closed and Open segmented controls for Radiator Flap.
Does Max Cooling open the radiator flaps automatically?
On supported configurations, activating Max Cooling can automatically open the radiator flaps.
Does Anti-Lag open the radiator flaps?
Current documentation states that supported Anti-Lag operation can automatically open the radiator flaps for additional cooling.
Is the selected Open or Closed state saved permanently?
No. The manual value is not stored in EEPROM and is cleared when the ECU resets or the vehicle goes to sleep.
Should I keep the radiator flaps open all the time?
OEM control is recommended for normal driving. Manual control should be used only when there is a clear cooling or diagnostic reason.
Check Your Vehicle
Control Supported BMW Radiator Flaps.
Connect the MG Flasher app and confirm that radiator-flap control is available for the exact vehicle and ECU.