Lexus GS460 Owner's Manual page 141

If the indicator does not come on even after shifting the shift lever to "S"
■
This may indicate a malfunction in the automatic transmission. Have the vehicle
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.
GS460: The AI-SHIFT automatically operates when the shift lever is in the "D" or
"S" position.
GS350: 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.)
While in power mode, the engine speed may stay high while depressing the accel-
erator pedal and may remain high after releasing the accelerator pedal. This does
not indicate a malfunction.
GS_G_U (OM30C11U)
May 21, 2010 1:06 pm
2-1. Driving procedures
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