1997 SC300 -My battery died. While jumping it, the panic alarm went off. Locking and unlocking the car with the fob quieted the alarm, but now the car will not start. Do I need to reset the security system, and if so, how do I reset it?

The battery has been fully charged, the open door light goes on, but the engine will not try to start. I tried locking the driver door with the key, which turned on the security red light for about 30 seconds, the it began blinking. I then unlocked the door and tried the key; nothing. I tried quickly unlocking the door twice; nothing.

 

Try locking and unlocking the drivers door with the key a few times in a row. Worked for my 92sc300 at the time. Not sure if you cycled the key enough

 

Try the passenger door also.....

 

Thanks for the suggestions. I just tried both doors 10 times with both the master and the valet keys. Unsuccessful. Still looking for ideas . . .

 

You may have accidentally blown a fuse... check all the big fuses in the main fusebox under the hood first with a multimeter not just by looking then if they are all ok try the ones inside.

 

Did you ever resolve this, I have the same issue.

 

Try again to clear it by closing doors, lock and unlock with master key, do this on both doors. If key fob, lock and unlock with that too.

also may help to put key in ignition in first or second position then disconnect negative battery terminal for a bit (5-10 minutes maybe). with master key still in ignition reconnect negative terminal and start her up.

if you have a key fob and the inner pieces are messed up that could be source of problem too. I’ve got a 99 sc300 and after dropping my fob, the case came opened and came apart. Car wouldn’t start until I had things back together correctly enough for it to recognize it as master key.

good luck and let us know what worked

GAsc300

 

I dont know what lexus chose to kill other than the starter with their security. If its just a starter kill (and could be that simple in the early 90’s) you can turn the key on and use a starter bump switch to rotste the engine and see if everything works as normal.