Automatic ECA Input
A compatible ethanol sensor can continuously provide the DME with the current ethanol content.
MG Flasher Custom Code FeatureFlex Fuel
Flex Fuel
Blending
Let a compatible MG Flasher calibration adapt to the ethanol content in the tank. Flex Fuel Blending can automatically adjust supported tuning parameters from pump fuel through higher ethanol blends using an ECA sensor or a manually configured ethanol value.
New to MG Flasher? How It Works
v7.3+
Custom Code
Auto
ECA Blending
Manual
Ethanol Override
Flex Fuel Status
Automatic Blending
Active
Ethanol Content
40%
ECA sensor reading
Active interpolation
Pump Fuel → Flex Fuel 1
Pump Fuel
20%
Flex Fuel 1
80%
Flex Fuel 2
0%
Visual example only. The tuner defines the ethanol breakpoints, maps and supported parameters for the installed calibration.
One Calibration. Changing Fuel.Adapt to What Is
Adapt to What Is
Actually in the Tank.
Ethanol content can change every time the vehicle is refuelled. A fixed ethanol calibration assumes one specific blend, while MG Flasher Flex Fuel Blending can use the measured or configured ethanol value to interpolate supported tuning parameters in real time.
The result is a more flexible workflow for compatible OTS maps and custom calibrations. The exact output, supported blend range and hardware requirements still depend on the vehicle, fuel system and tune.
Manual Override
Without a sensor, a known ethanol value can be configured in the app or through supported Custom Code controls.
Dynamic Calibration
Supported boost, fueling, ignition and other calibration areas can blend according to tuner-defined logic.
Safety & Validation
Map validation, sensor diagnostics and optional MG Flasher Limp Mode help protect compatible setups.
Calibration ArchitectureHow Flex Fuel
How Flex Fuel
Blending Works.
MG Flasher can interpolate between Pump Fuel, Flex Fuel 1 and Flex Fuel 2 calibration tiers. The tuner decides which tables blend and how ethanol content maps to the blending factor.
Pump Fuel
The base calibration tier used at the lower end of the configured ethanol range.
Blend factor: 0%Flex Fuel 1
An intermediate calibration tier for the tuner-defined mid-range ethanol target.
Blend factor: 100%Flex Fuel 2
An optional higher-ethanol calibration tier when blending factors extend above 100%.
Blend factor: 200%
0–100% Blend Factor
PF to FF1
A one-stage setup can interpolate between the Pump Fuel and Flex Fuel 1 tables. The ethanol content assigned to each end point is defined by the calibration.
100–200% Blend Factor
FF1 to FF2
A two-stage setup can continue from Flex Fuel 1 toward Flex Fuel 2. Valid FF2 calibration data is required wherever the configured blend factor exceeds 100%.
Important:
PF, FF1 and FF2 are calibration tiers, not fixed public promises of a specific fuel or power level.
The tuner defines the ethanol breakpoints, valid maps and supported hardware for the vehicle.
Ethanol InputSensor Reading or
Sensor Reading or
Manual Override.
Flex Fuel Blending uses an ethanol value as its input. That value can come from a compatible ECA sensor or from Ethanol Content Override. The override can be controlled in the app or through the existing 5K Custom Code Menu position.
Automatic Ethanol InputThe Sensor Supplies
The Sensor Supplies
The Active E%.
A compatible CAN-based Ethanol Content Analyzer continuously supplies the DME with the measured ethanol content. Flex Fuel Blending then applies the tuner-defined interpolation between the enabled PF, FF1 and FF2 calibration tiers.
Automatic
The value changes with the fuel mixture in the tank
No CCM
The sensor reading does not require a menu selection
Validation
Supported sensor faults can disable blending and use a fallback
Flex Fuel is calibration blending
The ECA provides the ethanol value. The tuner-defined PF, FF1 and FF2 tables determine how that value changes boost, fuel, ignition and other supported calibration areas.
ECA sensor input
Live Ethanol Value
Reading valid
Current ethanol content
40%
Automatic sensor input
0%E30E50E85
Input
ECA Sensor
→
Custom Code
Ethanol Value
→
Calibration
PF / FF1 / FF2 Blend
Visual example only. Exact ethanol breakpoints and blended calibration areas are defined by the installed OTS map or custom tune.
Manual Ethanol InputThe 5K Menu Controls
The 5K Menu Controls
Ethanol Override.
Flex Fuel Blending does not have a separate CCM menu position. The manual value is supplied through Ethanol Content Override, which occupies the 5K position in the Custom Code Menu.
5K
Ethanol Content Override in the CCM root menu
5× CEL
Counted confirmation of the override submenu
0 / 1K
Override OFF / ON inside the submenu
Not a Flex Fuel submenu
Explore Ethanol Content Controls →
The RPM gauge and CEL are controlling the ethanol input used by Flex Fuel Blending. They are not directly selecting PF, FF1 or FF2 calibration tiers.
Ethanol Content Override
OEM RPM Gauge + Check Engine Light
CCM active
Root-menu position
5K
Ethanol Override
Check Engine LightSlow CEL blinks
The slow blink confirms that the CCM root menu is active.
Root menu
Step 01 · Root menu
Navigate the OEM tachometer to 5K
While the CEL blinks slowly, move through the CCM root menu until the tachometer points to 5K for Ethanol Content Override.
What happens next?
The confirmed manual E% value becomes the ethanol input used by the compatible
Flex Fuel Blending calibration.
Interface demonstration only. The manual ethanol value must accurately match the fuel mixture. Exact availability depends on ECU software, Custom Code version and calibration configuration.
Setup WorkflowEnable Flex Fuel
Enable Flex Fuel
During Flashing.
The feature is configured in Custom Options before flashing a supported OTS map or compatible custom calibration.
Confirm ECU Compatibility
Verify that the connected ECU software supports Custom Code v7.3.x or newer.
Select a Compatible Calibration
Choose a supported MG Flasher OTS map or a custom tune with the required flex-fuel tables populated.
Enable Ethanol
Open Custom Options, enable Ethanol and enter the Ethanol settings submenu.
Enable Flex Fuel Blending
Activate the blending option, then select the installed ECA or configure the manual ethanol values.
Flash and Verify
Complete the flash and monitor the dedicated Flex Fuel status and ethanol data where available.
Hardware RequirementsMatch the Fuel System
Match the Fuel System
to the Ethanol Blend.
Ethanol increases fuel-system demand. The required hardware depends on the engine, power target, fuel mixture and calibration—not only on whether Flex Fuel Blending is enabled.
ECA Sensor
Required for fully automatic ethanol detection. The sensor must communicate with the DME over a supported CAN configuration.
Examples in the MG Flasher guide include Motiv ReFlex, Zeitronix and Fuel-It compatible setups.High-Pressure Fuel Pump
Higher ethanol blends and power targets may exceed the capacity of the factory HPFP. Upgrade requirements vary by platform.
Do not assume a stock fuel system is suitable for full E85 or a high-output calibration.Low-Pressure Fuel System
Higher ethanol demand can also require LPFP upgrades. A compatible low-pressure sensor can support additional protection logic.
MG Flasher documentation recommends monitoring fuel pressure for demanding ethanol setups.Motiv ReFlex Integration
Supported ReFlex integration can provide ethanol, low-pressure fuel and port-injection data to MG Flasher Custom Code.
Correct CAN ID selection and configuration are required to avoid data conflicts.
Hardware warning:
Never use a calibration or ethanol blend that exceeds the capacity of the vehicle's direct-injection,
high-pressure or low-pressure fuel system. Confirm the setup with the calibration provider or an experienced tuner.
Protection & ValidationBuilt to Detect
Built to Detect
Bad Data and Faults.
Compatible Custom Code configurations include validation and diagnostic mechanisms designed to prevent unsafe blending when required data is missing or a supported sensor reports a fault.
01
Calibration Data
Map Validation
The DME checks enabled PF, FF1 and FF2 calibration areas for usable data. Invalid data can disable blending rather than allow an unintended interpolation.
02
Sensor Monitoring
ECA Fault Detection
A supported sensor timeout or reported error can disable Flex Fuel Blending and return the strategy to its configured pump-fuel fallback.
03
Fuel System
Fuel-Pressure Protection
With compatible hardware and configuration, critically low LPFP pressure can trigger MG Flasher protection logic and reduce engine load.
04
Diagnostics
Custom Code DTCs
MG Flasher can record diagnostic codes for supported Flex Fuel, ethanol sensor, ReFlex and low-pressure fuel faults.
When protection is triggered
Boost can be reduced, the CEL may blink and a diagnostic fault can be recorded.
Open Support Resources
→
MG Flasher AppConfigure. Monitor.
Configure. Monitor.
Diagnose.
The app is used to select the ethanol input method during flashing, confirm the installed Custom Code version, monitor supported Flex Fuel parameters and diagnose compatible sensor or fuel-pressure faults.
Flashing Options
Enable Ethanol, Flex Fuel Blending and the correct sensor or override configuration.
Live Control & Diagnostics
Adjust Ethanol Override and inspect supported Custom Code values without preparing another full tune.
Vehicle Logging
Monitor ethanol content, blending status and relevant fuel-system parameters where available.
Map Validity
Compatible app versions can help identify disabled or invalid map data before it is selected.
CompatibilityCheck the ECU,
Check the ECU,
Calibration and Hardware.
Flex Fuel Blending is not automatically available on every supported vehicle. Exact availability depends on the ECU software, Custom Code version, engine platform, calibration data and fuel-system setup.
Custom Code v7.3.x+
The installed ECU software must support a compatible v7.3 or newer Custom Code release.
Valid Flex Fuel Data
The OTS map or custom tune must include the required enabled PF, FF1 and—where used—FF2 map data.
ECA or Override
The DME needs a valid ethanol input from a compatible sensor or a correctly configured manual value.
Hardware for the Target Blend
The HPFP, LPFP, injectors and related hardware must support the required fuel volume and power target.
Calibration SourceOTS Maps or
OTS Maps or
Custom Tuning.
The public workflow is similar, but the calibration source determines which blending tables, ethanol targets and hardware combinations are supported.
Supported Automatic Logic
Compatible MG Flasher OTS maps use MG Flasher's configured automatic blending logic when the feature and required patches are available for the ECU software.
- Choose the supported OTS map and fuel setup
- Enable Ethanol and Flex Fuel Blending during flashing
- The app identifies missing Flex Fuel patch support where applicable
Vehicle-Specific Calibration
A custom tuner can populate and configure the PF, FF1 and FF2 maps around the vehicle's exact hardware, ethanol range and performance goals.
- Tuner-defined blending factors and table selection
- Calibration matched to upgraded fuel-system hardware
- Custom logging, validation and revision workflow
FAQFlex Fuel
Flex Fuel
Blending FAQ.
Common questions about automatic ethanol adaptation, hardware, compatibility and MG Flasher Custom Code.
What is MG Flasher Flex Fuel Blending?
Flex Fuel Blending allows a compatible calibration to interpolate supported tuning parameters according to the ethanol content measured by an ECA sensor or supplied through a manual override.
Which Custom Code version is required?
Flex Fuel Blending requires a compatible Custom Code v7.3.x or newer release for the connected ECU software.
Do I need an ethanol sensor?
An ECA sensor is required for fully automatic ethanol detection. Without a sensor, a known ethanol content can be configured manually, but the accuracy of the blending input depends on the value entered by the user.
Does Flex Fuel Blending switch between fixed maps?
Not exactly. Switchable Maps selects a map slot. Flex Fuel Blending interpolates between enabled PF, FF1 and FF2 calibration tiers inside the active compatible setup according to tuner-defined logic.
Can I use E85 with the stock fuel system?
Do not assume that the stock fuel system supports full E85 or a high-output ethanol tune. Required HPFP, LPFP, injector and related upgrades depend on the vehicle, engine, blend and power target.
What happens if the ethanol sensor fails?
With compatible safety configuration, a supported sensor timeout or fault can disable Flex Fuel Blending, apply a pump-fuel fallback strategy, reduce load through MG Flasher Limp Mode and record a diagnostic code.
Can Flex Fuel Blending be used with OTS maps?
Yes, where a compatible MG Flasher OTS map, ECU software and required Flex Fuel patch are available. The app can notify the user when a required reference or patch is missing.
Can a custom tuner configure Flex Fuel?
Yes. A compatible custom tune can use tuner-defined PF, FF1 and FF2 data, blending factors, enabled map categories and supported hardware configurations.
How do I check whether my vehicle is supported?
Download MG Flasher, connect through a supported ENET method and use the app to check the exact ECU software and available Custom Code support before purchasing or flashing.
Ready to Check Your Setup?Use Flex Fuel Blending
Use Flex Fuel Blending
with MG Flasher.
Find your engine, check ECU compatibility in the app and confirm the correct fuel-system hardware and calibration.