Info - Transaxle Shift Lag and/or Hesitation During Warm-Up Following Initial Start Up - Normal Characteristic, No Service Necessary

The purpose of this bulletin is to inform Saturn Retailers of normal shift characteristics of the 5AT 5-speed automatic transaxle (RPO MJ7/MJ8) during initial start up following a cold soak.

The 5AT transaxle (RPO MJ7/MJ8) is a 5-speed, electronically controlled, automatic transaxle featuring transaxle shift calibration that adjusts and assures consistent shift feel. However, transaxle shift feel adaptation on the 5AT automatic transaxle does not initiate until after the first series of shifts are completed, after a cold soak (i.e. when the vehicle parked for extended periods of time). The Saturn VUE 5AT automatic transaxle shift calibration is designed to provide optimum shift feel during normal driving, and more specifically, during normal operating temperatures (transaxle fluid temperatures of 65-110°C [150-230°F]). This method of providing consistent shift feel is to ensure the best possible shift feel during the ideal operating temperatures. Because of this programming, some customers may experience shift performance that is described as "firm" or a sensation of a slight up shift lag when comparing the shift feel after warm up to pre-warm up operating modes.

During initial pre-warm up periods, customers may experience a lag/delay during 1-2, 2-3 upshift after accelerating from a stop, or during acceleration during a rolling stop. The delayed 1-2/2-3 upshift can occur between the speeds of 32-48 km/h (20-30 mph), during the initial warm up period. As the transaxle fluid warms, the transaxle control module (TCM) calibration is optimized to refine shift feel for smoothness and responsiveness during the normal range of temperatures experienced.

The shift feel characteristics experienced by customers is considered a normal characteristic. There is no need to attempt a repair for cold shift performance.