DATAP R O-45™
TESTING: Change the LCD display channel to the throttle channel. Open and close the throttle, causing a significant reading change on the LCD display.
The factory calibration inside your DATAPRO-45™ for your throttle position sensors is a single ended range from 0 to 100.0, intended to represent percent throttle. Depending on your installation, there may be three ways in which the LCD readings differ from ideal. You may use the D ATAPRO ON-LINE software to customize the calibration for your installation. For details on this feature, see the on-line software help. This process is
very similar to adjusting the suspension sensor readings.
1. More and less throttle, near 100 or near 0 may be reversed.
calibration to use the coefficients B = -64251 and C = 65568768. coefficient B is a negative number.
2. The reading may not be zero when the throttle is at rest. Make a note of the digits displayed instead of zero. For example, if 12.7 is displayed (a little more than ten), then note the digits 127 (a little more than 100). Multiply this number by 65,536 and then subtract it from the C coefficient. Note that if the display was a negative number, then you need to subtract a negative number, which is tantamount to adding
3. The reading change under full deflection is not 100.0. Make a note of the deflection from rest. Be sure to take into account any difference in the at-rest position from zero. For example, if 12.7 is displayed at rest and 85.4 is displayed at full deflection, then the reading change under full deflection is actually 72.7. If your desire is for this reading change to be 100.0, then the current reading change is only 72.7% of the desired reading change. Conversely, the desired reading change is 1.376 times the current reading. (Get that by dividing 100.0/72.7.) To adjust the reading change, multiply the B and C coefficients by the number you calculate (1.376 in this example).
Note that, once you get close to ideal, adjustments to the zero reading and the reading change under full deflection can effect each other. It may take a few repetitions of the process to get things exactly right. However, since sensors, mounting points, throttle linkage, and driver foot force are liable to change very slightly over time, don’t spend too much effort trying to get things perfect. The readings will only change from perfect later. It is certainly not recommended to worry about the digit to the right of the decimal place. This digit is provided strictly for seeing minute changes in throttle position and for accurately calculating deflection rates.
Copyright 1999 Computech Systems Inc