2007 Lexus GS 350 Owners Manual - Page 179

2-1. Driving procedures n Downshifting restrictions in "S" mode The shift lever cannot be downshifted if the following speeds are exceeded. (The warning buzzer will sound twice in this situation.) Downshifting 5→4 4→3 3→2 2→1 Maximum speed mph (km/h) GS430 120 (194) 88 (142) 59 (95) 24 (38) GS350 124 (200) 87 (141) 56 (91) 28 (45) 2 When driving The maximum speeds can get lower when the engine is not warm such as in cold climates or before warm-up. n When driving with the cruise control system (or dynamic radar cruise control sys- tem) The engine brake will not operate in the "S" mode, even when downshifting to "5" or "4". (→P. 124, 127) n Snow mode automatic deactivation Snow mode is automatically deactivated if the engine switch is turned to "ACC" or "IG-ON" mode after driving in snow mode. n If the shift lever cannot be shifted from "P" →P. 484 n If the indicator does not come on even after shifting the shift lever to "S" This may indicate a malfunction in the automatic transmission system. Have the vehicle inspected by your Lexus dealer immediately. (In this situation, the vehicle will operate as if the shift lever is in "D".) n AI-SHIFT The AI-SHIFT automatically shifts the gear to the optimal position according to the driver's input and driving conditions. The AI-SHIFT automatically operates when the shift lever is in the D position. (Shifting the shift lever to the S position cancels the function.) 103