Before Drive-By-Wire can be used, its four primary sensors need to be calibrated.


There are usually two sensors in the pedal system. They typically share a 5V reference and Ground, and then output two signals that go between zero and five volts as the pedal is moved. These signals have a slight offset, so the ECU can see that the sensors and signals are indeed working correctly. if a sensor were to fail, then the relationship between these two signals would change, and the ECU would notice the signals being "out of sync" and will then trigger a DBW fault mode, which will then safely close the throttle. The throttle plate also has a similar two-sensor set-up to give protection from a motor/driver failure in the throttle control mechanism.


Calibrating the Pedal Position Sensors


First ensure you have correctly set the analog channels for your pedal sensors in the Analog Input settings under the IO Settings Tab. Both Pedal Position 1 Raw and Pedal Position 2 Raw should be assigned to their respective Ana V pins.


Below, you can see we have wired the pedal signal lines to Ana V1 and Ana V3. You can also see we have wired the throttle signal wires to Ana V2 and Ana V5, but we will cover those in a later section,




With the Pedal position sensors wired, you should note the DBW A Pedal Pos Raws 1 & 2 varying as you move the throttle pedal. If they do then you are ready to calibrate them.


Open the DBW Settings as pictured below. It may be worth creating a new tab for this under layout manager.


Now, moving the pedal, note the minimum and maximum voltages for both sensor channels of the pedal sensor. Input these in the left hand columns of both of the DBW A Pedal Pos. HRT tables. In the example below, you can see these numbers highlighted in green.


After this, sweeping the throttle pedal from closed to open should show 0-100% in the DBW A Pedal Pos 1 & 2 % readout DROs. DBW A Calc. Pedal Pos will also then show 0-100% as a combined reading of the drivers demanded throttle position (when DBW mode is set to anything other than OFF in the DBW Settings Driver.)



You can now repeat the same for the THROTTLE PLATE position sensors. We recommend you physically push the throttle plate fully closed and fully open to capture the DBW Throttle Pos Raw values as most DBW plates rest slightly open if the motor fails as a limp mode. Complete the DBW A Throttle Pos 1 & 2 HRT tables as before.


Note for max/min voltages on the throttle position sensors, you can set the mode for manual duty to +100 and -100 to get the range of the throttle rather than manipulating it by hand.  If you do move it by hand, set DBW mode to 'off' first for safety.


Both Throttle and Pedal sensors will now be correctly calibrated.