Flex Fuel Composition/Temperature Sensor

Flex Fuel Composition/Temperature Sensor

A Flex Fuel Composition/Temperature Sensor is digital sensor used to monitor the ethanol content of the fuel as well as the fuel temperature. This can be used with your Elite ECU for Flex Fuel tuning to suit a varying blend of ethanol in the fuel, for datalogging, and for Engine Protection purposes.  The Haltech Flex Fuel Composition Sensor uses one signal wire with a digital frequency to report ethanol percentage to the Elite ECU, and a pulse width to report fuel temperature.



Wiring

Information on how to wire the Flex Fuel Sensor is written on the sensor body.
Pin
Description
Haltech Connection
OUT
Signal
Spare DPI or SPI
GND
Ground
Signal Ground - Black/White
VCC
12V+ Switched
Grey/Red in Loom


Wiring Tab



Connections

Flex Fuel Composition Input

Select an appropriate SPI to use for the Haltech Flex Fuel Composition Sensor.  Only SPI's will read a frequency sensor. An AVI cannot be used.

                        Edge should be set to RISING. Sensor Type HALL EFFECT. Pullup ENABLED.  Frequency Time Constant 1.



Calibration - Fuel Tab

This allows calibrations for a Flex Fuel Composition Sensor to be loaded or saved.  If your sensor calibration is not listed, a custom calibration can be created with the data provided by the sensor manufacturer.  The default calibration will be for the digital Haltech Flex Fuel Composition Sensor.




Display – Fuel Tab


Warning Minimum

When the Flex Fuel Composition reads below this amount, any items on the ESP software viewing this channel will flash Red as a warning of low Flex Fuel Composition.

Warning Maximum

When the Flex Fuel Composition reads above this amount, any items on the ESP software viewing this channel will flash Red as a warning of high Flex Fuel Composition.

 

Calibration – Temperature Tab

This allows calibrations for a Flex Fuel Composition Sensor to be loaded or saved.  The default calibration will be for the digital Haltech Flex Fuel Composition Sensor.

 



Display – Temperature Tab


Warning Minimum

When the Flex Fuel Composition reads below this amount of temperature, any items on the ESP software viewing this channel will flash Red as a warning of low Flex Fuel Composition Temperature.

Warning Maximum

When the Flex Fuel Composition reads above this amount of temperature, any items on the ESP software viewing this channel will flash Red as a warning of high Flex Fuel Composition temperature.

 


Diagnostics Tab

The settings in this tab allow limits to the set for the detection of either fault conditions, or conditions that could be considered to cause engine damage related to the Flex Fuel Composition Sensor.


Raw Min

When enabled, this allows for the error code P0178 to be set when the frequency or voltage is below the set amount. This is used to detect a short or disconnection with the wiring.  If the Engine Protection function is active a DTC Severity level can be selected for this condition if desired. (Default = Disabled)

Raw Max

When enabled, this allows for the error code P0179 to be set when the frequency or voltage is above the set amount. This is used to detect a short or disconnection with the wiring. If the Engine Protection function is active a DTC Severity level can be selected for this condition if desired.  (Default = Disabled)

Temperature Raw Min

When enabled, this allows for the error code P0182 to be set when the pulse width is below the set amount. This is used to detect a short or disconnection with the wiring.  If the Engine Protection function is active a DTC Severity level can be selected for this condition if desired. (Default = Disabled)

Temperature Raw Max

When enabled, this allows for the error code P0183 to be set when the pulse width is above the set amount. This is used to detect a short or disconnection with the wiring. If the Engine Protection function is active a DTC Severity level can be selected for this condition if desired.  (Default = Disabled)

 

Main Setup > Engine > Fuel

Fuel Type

If it is desired to use the Flex Fuel Composition Sensor with the tuning of the engine, the Fuel Type should be changed to Flex Fuel.  Selecting this will automatically add a fuel correction with varying ethanol percentage in the fuel to match fuel requirements for the calculated fuel stoichiometric ratio.  A Fuel Composition Scalar table is then available to vary how this correction is applied.


Lambda

Fuel Composition Corr

This table allows for the Target Lambda to be changed with varying amounts of ethanol. Useful when closed-loop O2 Control is being used and the target is to be altered with changing ethanol.

Fuel

Fuel Composition Corr

This table allows for corrections to be made where the automatic calculation is not correct. The default for this table is to have all numbers as “0.0” and to adjust as required.

Fuel Composition Scalar

This table allows for adjustment of how the automatic correction is applied over changing ethanol content.

Ignition

Fuel Composition Corr

This table allows for the ignition timing to be corrected for the highest amount of ethanol percentage (typically 100% ethanol).

Fuel Composition Scalar

This table allows control of how the Ignition – Fuel Composition Corr table is to be applied based on the varying amount of ethanol in the fuel.

Boost Control

Duty Cycle Flex Fuel Composition Correction

This table allows control over the final boost control duty output based on the mount of ethanol in the fuel. This will affect Open Loop Duty Cycle, or the Closed Loop Base Duty Cycle.

Target Pressure Flex Fuel Composition Correction

Available when the Boost Control is configured to use Closed Loop control. This table allows control over the Closed Loop Target Pressure with varying amounts of ethanol in the fuel.


Miscellaneous

The Flex Fuel Composition channel can be used for many other purposes throughout the Elite ECU. Some common examples are:

    • Fuel Prime Pulse and Fuel Cranking tables can be expanded to include Flex Fuel Composition as one of the axis. This can assist with engine starting under varying amounts of ethanol in the fuel.
    • Lambda Target, Fuel Base, and Ignition Base tables can be expanded into 4D to include Flex Fuel Composition as one of the axis. This can allow full control of engine mapping with carrying amounts of ethanol in the fuel.
    • Fuel Temperature correction can be added via a Generic Correction table. 




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