I've a 99 Lexus ES 300 that has an automatic transmission. I would like to convert it to manual shift - i.e. use the existing auto transmission, but shift it manually, by switching on/off the solenoids. I am new to working on transmissions, so please advise if it is possible. I got to know that Solenoid 1 and 2 are switched on/off when gears are changed. eg: 1st gear Solenoid 1 is ON and solenoid 2 is OFF, for O/D both are OFF etc. However, my car has 5 solenoids - SL1, SL2, SLT, DSL and S4 (I'll try to attach the diagram here). Is Solenoid 1 and 2 the same as SL1 and SL2? Will I need to control the other solenoids if I have to shift manually? Should I take care of anything else?