Ethanol Content Display
Temporarily use the tachometer to show the active ethanol percentage reported by a sensor or override value.
MG Flasher Custom Code FeatureEthanol Content
Ethanol Content
Display & Override
Read the active ethanol percentage from a supported sensor—or provide a manual value when a sensor is unavailable. MG Flasher can display ethanol content through the tachometer and expose compatible override controls in the app.
Building a Flex Fuel setup? Explore Flex Fuel Blending →
Interactive Example
Ethanol Content
Custom Code v7.1+
Sensor Reading
30%
Ethanol Content
Tachometer Display
3000 RPM
Input Source
ECA Sensor
The tachometer display uses 100 RPM per 1% ethanol. For example, 3000 RPM represents 30% ethanol.
Overview
Two Ways to Tell the ECU What Is in the Tank.
Custom Code v7.1 introduced Ethanol Content Display and Ethanol Content Override. Together, they allow the driver to view the current ethanol value and—when required—replace the sensor value with a manually selected percentage.
These functions provide ethanol information. They do not by themselves create a Flex Fuel tune. Automatic calibration blending requires compatible Flex Fuel Blending logic, the correct Custom Code, prepared map data and a supported vehicle setup.
Ethanol Content Override
Provide a manual ethanol value when no ECA is installed, when a sensor is malfunctioning or when a fixed value is required.
How It Works
Sensor Data or a Manual Value.
The ECU uses the configured ethanol source and makes that value available to supported Custom Code functions.
Read an ECA Sensor
A supported ethanol sensor communicates its current value through the configured PT-CAN connection.
Use an Override
Without a working sensor, a manual percentage can be selected through supported app or CCM controls.
View the Active E%
Hold the supported rocker input to temporarily display the active ethanol percentage on the tachometer.
Use the Value in Supported Logic
Compatible Flex Fuel or diagnostic functions can use the configured ethanol value where the setup supports it.
Ethanol Content Display
Read E% Through the Tachometer.
With the engine running, hold the rocker fully upward to activate the Ethanol Content Display. The tachometer temporarily moves to the active ethanol value and returns to normal operation when the rocker is released.
The scale is direct: each 100 RPM represents 1% ethanol. A 2000 RPM indication therefore represents 20% ethanol content.
1000 RPM
10% Ethanol
2000 RPM
20% Ethanol
5000 RPM
50% Ethanol
7500 RPM
75% Display Limit
The tachometer-based display is limited by the physical 7500 RPM scale. Higher values can still be handled through compatible in-app controls where supported.
Ethanol Content Override
Provide a Manual Value When Needed.
The override can replace the sensor reading—or provide a value when no sensor is installed.
Toggle + Percentage Picker
On compatible Custom Code v7.1+ setups, enable the override and choose a value from 0% to 100% in 5% increments.
Explore Live Control →Read and Set the Override
Review the current override status and value, then enable, disable or update it through the app diagnostics page.
Explore Custom Code →Use Position 5K
Navigate to the Ethanol Content Override submenu through the supported steering-wheel controls.
View CCM Steps →
OEM RPM Gauge & CEL FeedbackDisplay E%.
Display E%.
Or Set an Override.
Ethanol Content Display and Ethanol Content Override use the same OEM tachometer and Check Engine Light, but the signals mean different things.
Slow CELEthanol Content Display is active
5KEthanol Override in the CCM root menu
5× CELOverride submenu confirmation
100 RPMRepresents 1% ethanol content
Five blinks do not mean 5% ethanol.
Five counted blinks identify the Ethanol Content Override submenu because it occupies the 5K position in the Custom Code Menu.
OEM instrument-cluster feedback
RPM Gauge + Check Engine Light
Custom Code
Active ethanol content
3K
30% Ethanol
Check Engine LightSlow CEL blinks
The slow blink indicates that Ethanol Content Display is currently being used.
Display signal
0%25%50%75%
Select the override state
0%25%50%75%
Ethanol Content Display
3000 RPM represents 30% ethanol
Hold the supported rocker fully upward. The CEL blinks slowly while the tachometer temporarily displays the active ethanol percentage.
CCM / tachometer range0–75%
Compatible in-app range0–100%
Interface demonstration only. The manual value must accurately match the ethanol mixture in the tank. Availability depends on ECU software, installed Custom Code and ethanol-source configuration.
Relationship to Flex Fuel
Ethanol Information Is Not the Calibration.
Ethanol Content Display and Override tell supported Custom Code what ethanol percentage should be used. Flex Fuel Blending is the separate calibration system that uses that value to interpolate supported boost, fuel, ignition and other map data.
Installing an ECA or entering an override value does not automatically make a vehicle Flex Fuel capable. The ECU still requires compatible Custom Code v7.3+, correctly prepared maps and suitable fuel-system hardware.
Explore Flex Fuel Blending →
01
Ethanol Source
→ECA sensor or manual override provides the active E% value.
02
Custom Code
→The ECU reads the configured value and exposes it to supported logic.
03
Flex Fuel Blending
Prepared calibration data is blended according to the active ethanol percentage.
Compatibility & Requirements
Check the Complete Configuration.
Availability depends on the vehicle, ECU software, Custom Code version and ethanol-source configuration.
Custom Code v7.1+
Ethanol Content Display and Override were introduced with Custom Code v7.1.
Supported ECU Software
The installed ECU software must have a compatible Custom Code release available.
Configured Ethanol Source
Use a supported ECA on the correct CAN ID or configure the manual override accurately.
Correct Calibration
Any Flex Fuel use still requires map data prepared for the intended ethanol range and hardware.
Important Notes
Use an Accurate Ethanol Value.
Incorrect input data can make a compatible calibration behave differently from the tuner’s intended setup.
Verify ECA Communication
If ethanol stays at 0%, fluctuates or jumps unexpectedly, check wiring, grounding and the selected CAN ID.
Enter the Real Tank Content
When using an override, update the value whenever the ethanol mixture changes.
Understand the Fallback
Supported sensor faults may disable Flex Fuel Blending and return the strategy to its configured pump-fuel fallback.
Match Hardware to the Blend
Higher ethanol content can require upgraded high- and low-pressure fueling components.
FAQ
Ethanol Content FAQ.
Common questions about the display, override, sensor input and Flex Fuel relationship.
What is Ethanol Content Display?
It temporarily uses the tachometer to show the active ethanol percentage reported by a supported sensor or manual override value.
What is Ethanol Content Override?
It lets the user replace the sensor value—or provide one without a sensor—with a manually selected ethanol percentage.
Which Custom Code version is required?
Ethanol Content Display and Override were introduced with Custom Code v7.1. Exact availability still depends on ECU software support.
How does the tachometer show ethanol content?
Each 100 RPM represents 1% ethanol. For example, 2000 RPM represents 20% ethanol content.
What is the maximum manual override value?
The tachometer-based CCM input is limited to 75%. Compatible in-app diagnostics or Live Control can provide values up to 100% where supported.
Do I need an ethanol sensor?
No. A manual override can be used without a sensor, but the user must accurately update the value when the fuel mixture changes.
Does this automatically enable Flex Fuel?
No. Flex Fuel Blending also requires compatible Custom Code v7.3+, properly prepared calibration data and suitable fuel-system hardware.
What should I check if the ethanol value is incorrect?
Review the sensor wiring, grounding, CAN ID and app configuration. If using an override, verify that the entered value matches the actual tank mixture.
Ready to Check Your Setup?
Read or Override Ethanol Content with MG Flasher.
Confirm vehicle support, Custom Code availability and the correct ethanol-source configuration before flashing.