Pinion Factor Setting
The TCM in F4ACI transaxle uses the rotation speed of the transaxle output shaft to calculate the vehicle speed and cumulative distance traveled. Because of this, it is necessary to input (or update) the tire size coefficient into the TCM memory after the TCM has been replaced or the tire size has been changed.Select "Special function" on the scan tool and then set the scan tool to Pinion Factor mode. Then input (or update) the tire size coefficient into the TCM memory. Note that new TCM's do not have a tire size coefficient already input.