Upshift Adapts (1-2, 2-3 and 3-4): Notes

The PCM/TCM monitors the automatic transmission input speed sensor (ISS) and the vehicle speed sensor (VSS) in order to determine when an upshift has started and completed. The PCM/TCM measures the time for the upshift. If the upshift time is longer than a calibrated value, then the PCM/TCM will adjust the current to the pressure control (PC) solenoid valve to increase the line pressure for the next shift in the same torque range. If the upshift time is shorter than the calibrated value, then the PCM/TCM will decrease the line pressure for the next shift in the same torque range.