I have a 93 Ls 400 Lexus .the fuel pump has no power coming to the pump but if I connect to the battery it works . All fuses and relays are good .what do you think it is?

The fuel pump relay should be in the relay box under the drivers dash left of the steering column

To answer your question specifically it would be no. There
is no inertia switch that feeds the fuel pump that can be turned off or reset . The engine control computer turns on a series of two different relays to control power to the fuel pump. When in the start position the circuit opening relay and the fuel pump relay or both energize causing the fuel pump to run at full pressure or fast speed. From there the engine control computer determines which demand is on the fuel pump and either turns off the fuel pump relay and leaves
the circuit opening relay on to supply power through a resistor to slow the pump down for less demand. The EFI main relay is the main supply relay to both of these sub relays. The fuel pump is powered up ultimately by the 20 amp EFI number one fuse. All of these components are located in the fuse box under the hood. If the circuit opening relay is not working it's powered up by the 10 amp
ignition fuse inside the vehicle. It's unlikely it is the 10 amp ignition fuse because that powers up a lot of other things also.

First, please post your question only once.
There is NO INERTIA SWITCH on your vehicle.
The only thing to check is FUSE #1, which is a 20A fuse that provides power to your EFI control. If that is good, check for voltage at the fuel pump when the vehicle is turned on. If it has power to the fuel pump but the fuel pump is not running, replace the fuel pump.

Fuse bank should be in a black box under the hood in the engine compartment, usually its close to the battery.

Toyota products usually don't use a shut-off for the fuel system.
If the fuel pressure is low, you would need to check the fuel pump relay for power and then the pump.

Read the last post:
http://us.lexusownersclub.com/forums/index.php?showtopic=66180

problem with immobilisor call a autolocksmith to reset it for you or the dealer

ck relay to fuel pump bad

yes have the computer repaired and this should fix the problem. these cars are known for have the computers go bad.

You will have to remove your back seat to gain access to fuel pump. Fuel tank is located in trunk. No need to take fuel tank down.