Upshift Control and Torque Converter Clutch (TCC) Apply

The PCM calculates the upshift points based primarily upon two inputs:
- Throttle angle
- Vehicle speed

When the PCM indicates that a shift should occur, an electrical signal is sent to the shift solenoids, which in turn move the valves to perform the upshift.

The shift speed charts refer to THROTTLE ANGLE instead of MIN THROTTLE or WOT in order to make shift speed measurement more uniform and accurate. A scan tool should be used in order to monitor this throttle angle. Some scan tools have been programmed to record shift point information. Check the instruction manual in order to see if this test is available.

With the gear selector in Overdrive (D4), perform the following steps:
1. Refer to SHIFT SPEED and choose a percent throttle angle of 5, 10 or 25. Note the desired shift speeds for 2nd, 3rd and 4th gear.
2. Set up the on-board diagnostics or TECH 2 (or similar scan tool) to monitor PERCENT THROTTLE OPENING and VEHICLE SPEED.
3. Accelerate using a steady increasing throttle pressure.

Important: Shift points may vary due to engine operating conditions. The PCM interprets numerous electronic signals from various operational sensors in the vehicle. This may also cause a variation in shift points.

4. Note the shift speed point gear engagement for each of the following gears:
- 2nd gear
- 3rd gear
- 4th gear

Important: The TCC should not apply unless the engine coolant has reached a minimum operating temperature of 60° C (140° F). Drive the car approximately 15 minutes to verify that this temperature is exceeded.

5. The Torque Converter Clutch (TCC) should apply in Third or Fourth gear. Note the speed shift point for this TCC apply. If you do not notice the apply, refer to TORQUE CONVERTER CLUTCH EVALUATION AND DIAGNOSIS TORQUE CONVERTER CLUTCH DIAGNOSIS.