a. D position test:
Shift into the D position and fully depress the accelerator pedal and check the following points.
Check that the 1 --> 2, 2 --> 3, 3 --> 4 and 4 --> 5 up-shifts take place at the shift point shown in the automatic shift schedule (See SERVICE DATA ).
5th Gear Up-shift Prohibition Control
2006 TRANSMISSION A750E Automatic Transaxle - Sequoia
• Engine coolant temperature is 55°C (131°F) or less and vehicle speed is at 32 mph (51 km/h) or less.
4th Gear Up-shift Prohibition Control
• Engine coolant temperature is 40°C (104°F) or less and vehicle speed is at 28 mph (45 km/h) or less.
5th Gear Lock-up Prohibition Control
• Brake pedal is depressed.
• Accelerator pedal is released.
• Engine coolant temperature is 60°C (140°F) or less.
2. Check for shift shock and slippage.
Check for shock and slippage at the 1 --> 2, 2 --> 3, 3 --> 4 and 4 --> 5 up-shifts.
Check for abnormal noise and vibration when up-shifting from 1 -- > 2, 2 -- > 3, 3 -- > 4 and 4 -- > 5 while driving with the shift lever in the D position, and check while driving in the lockup condition.
The check for the cause of abnormal noise and vibration must be done thoroughly as it could also be due to loss of balance in the differential, torque converter clutch, etc.
Check vehicle speeds when the 2nd to 1st, 3rd to 2nd, 4th to 3rd, and 5th to 4th kick-downs take place while driving with the shift lever in the D position. Confirm that each speed is within the applicable vehicle speed range indicated in the automatic shift schedule (See SERVICE DATA ).
5. Check for abnormal shock and slippage at kickdown.
6. Check the lock-up mechanism.
• Drive in the D position (5th gear), at a steady speed (lock-up ON).
• Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
If there is a sudden increase in engine speed, there is no lock-up.
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