My 1999 RX 300 died suddenly while driving today. The washer fluid light came on and bulb out warning also. I tried to restart it and it spins over but won't fire. I have a code reader checked for codes and no communication. I inspected the 7.5 and 20 amp ECU fuses and found the 20 blown. I replaced it and the vehicle started but I did smell slight electrical odor. The check engine light is now on and I have a P0505. I unplugged the IAC valve and removed the electrical portion and it does smell like its fried. The other problem is I checked wiring with my volt meter and there is no voltage on the yellow/red wire. I don't know if it's open somewhere or the ECU is toast. Any help appreciated!
update I have ohmed out the wire from the ECU to the IAC valve and it's good. With the key on I'm getting .3 volts on the wire and I don't know what the spec is but assuming it should be more.

 

UPDATE I never did find out the specified voltage on that wire went ahead with replacing the IAC valve. Drove it 2 complete drive cycles and it runs good code didn't return. I suspect the coil was shorted on the old valve.

 

I hope it's o.k. I didn't think the IAC could cause it to die while driving and keep it from starting.

 

Agreed, but it popped a fuse and took out one circuit which may have been essential to run ... collateral damage.

Salim