Lexus GS430 - Page 123

103
2-1. Driving procedures
2
When driving
■ 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.)
The maximum speeds can get lower when the engine is not warm such as in cold
climates or before warm-up.
■ When driving with the cruise control system (or dynamic radar cruise control sys-
tem)
The engine brake will not operate in the “S” mode, e
ven when downshifting to “5” or
“4”. (P. 124, 127)
■ Snow mode automatic deactivation
Snow mode is automatically deactivated if the e
ngine switch is turned to “ACC” or
“IG-ON” mode after driving in snow mode.
■ If the shift lever cannot be shifted from “P”
P.
484
■ 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
v
ehicle inspected by your Lexus dealer immediately. 
(In this situation, the vehicle will operate as if the shift lever is in “D”.)
■ 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. (Shift-
ing the shift lever to the S position cancels the function.)
Downshifting
Maximum speed
mph (km/h)
GS430 GS350
54 120 (194) 124 (200)
43 88 (142) 87 (141)
32 59 (95) 56 (91)
21 24 (38) 28 (45)