Road Test
- Shift gear selector to each shift position. Ensure shifts are immediate and not harsh. With gear selector in "D" position, accelerate vehicle using increasing throttle pressure. Note shift speed gear engagements for 2nd and 3rd gear. Also note shift speed when TCC applies. TCC should apply at 23-42 MPH.
- At vehicle speeds of 25-55 MPH, TCC should release and transaxle should downshift to 2nd gear when accelerator is depressed to half throttle or wide open throttle.
- At vehicle speeds of 25-55 MPH, release accelerator while moving gear selector to "2" position. TCC should release, transaxle should downshift to 2nd gear and engine braking should occur.
- Move gear selector to "D" position and accelerate vehicle to 25 MPH. Release accelerator while moving gear selector to "1" position. TCC should release, transaxle should downshift to 1st gear and engine braking should occur. Shift points should agree with those listed in charts. See Fig 1
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- If shift points do not agree with charts, check ATF level, Throttle Valve (T.V.) cable adjustment and manual control linkages. See appropriate TRANSMISSION SERVICING - A/T article in the TRANSMISSION SERVICING section. Ensure engine is tuned properly. If fluid level, cable adjustment and control linkages are okay, check line pressure. See LINE PRESSURE TESTS
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Courtesy of GENERAL MOTORS CORP.