Theory Of Operation

The transmission control system uses three speed sensors, one to measure input RPM, one to measure Transfer Speed output RPM of the main transmission assembly, and a third to measure the final transmission output RPM. These inputs are essential for proper transmission operation. Therefore, the integrity of this data is verified through system checks. When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding gear ratio error trouble code is set. The transmission will go into Limp-in mode after four gear ratio error events occur in a given driving cycle.