I EXPERIENCED THE EXACT SAME PROBLEM. THE LEXUS ERROR CODE IS "62"
THE CAUSE OF THE LOW POWER AT TAKE-OFF (START) IS THE #1 AND #2 SOLENOID VALVES WHICH ARE NOT DOWNSHIFTING TO #1 GEAR, HENCE THE NEED TO MANUALLY SHIFT TO #1 GEAR.
YOU WILL NEED TO PURCHASE SOLENOIDS #1 AND #2. THEY ARE WIRED TOGETHER. PART #85420-32102.
DEALER PRICE IS $259.07. "TOYOTA PARTS EXPRESS" WILL SELL YOU A GENUINE TOYOTA PART FOR $194.69. THEY ARE BASED IN FLORIDA. (877)-771-7278. BRIAN BENNETT IS THEIR TECH MAN. LABOR CHARGES ARE ABOUT $300.00.
THE SOLENOIDS ARE LOCATED INSIDE THE TRANSMISSION PAN, AND CAN BE REACHED BY REMOVING THE OIL PAN. YOU WILL ALSO NEED A NEW GASKET FOR ABOUT $16.00 AND SOME ADDITIONAL ATF FLUID.
THIS IS ALSO A GOOD OPPORTUNITY TO CHANGE THE OIL FILTER. COST IS $26.00 + $10.00 FOR FREIGHT.
I USE AMSOIL SYNTHETIC ATF. IT IS EXPENSIVE BUT VERY GOOD, WORKS WELL AND HELPS PRESERVE THE GEARS AND ALL MOVING PARTS.
LOOK UP THE AMSOIL WEB SITE, IT IS VERY HELPFUL.
I HOPE THAT THIS INFORMATION IS HELPFUL,
Ludlow Technologies.
WILLIAM LUDLOW.
WLUDLOW@knology.net
