engine immobilizer??

yesterday this happened twice. i tried to start my 2006 v6 taco and the dash lights flashed for a split second before all power was lost. it was like i had no battery installed. i figured it might be the 140A alternator fuse, but i checked all my fuses and they were all good. then after awhile, it would work fine. today i started it a few times with no problem.

im not sure what the engine immobilizer does exactly. does it cut power if it doesnt recognize a key?

im thinking maybe the key is going bad, or possibly the eng immo system?

anyone have some cents they want to throw in?

thanks

 

engine immobilizer will let the engine turn over it just will cut fuel and spark.... so thats not it

 

hmm... thanks.

that helps alot. it cuts a bunch out the things i cant deal with myself. i hope it doesnt happen again. it all seems fine now and i really dont want to tear into the truck for a glitch in the computer or something. our CPU is in the cabin right?

 

yes the ecu is in right behind the glove box on the right... do u have an aftermarket alarm? and what exactly happened when u turned the key?

 

no alarm. as soon as i turned the key, all power was cut to the truck. even if i took the key out, i couldnt even turn on the dome lights. i left the headlight switch on to notify me when power came back while i was in the fuse box. just out of the blue, it would fix itself. it only happened twice, and i havent had a problem since. wierd...

 

battery is just fine. terminals are tight and in good condition.

 

what are you suggesting? its not weak when it cranks over or anything.

 

i think its a year and a half old. red top optima.
i was hoping it was something stupid like a key going bad, but if the immo doesnt cut power like an alarm does then idk. ill just wait and see. just wondering if anyone had a good idea of a component causing that problem. maybe ill see if there is corrosion or a loose connection for the 140A fuse. i think that if that had something to do with the problem then it would cause those symptoms.

 

Just out of curiosity, did you leave the headlights on? I know the lights turn off automatically, but I've seen two Tacomas that lost all power for a short time and the only thing I could link between the two was that the lights had been left on and the door was opened to automatically shut them off.

 

ya, i usually leave the headlight switch on all the time. do you think its hard on the ignition switch or something?

 

Sounds like a bad ground connection. Remove your terminals and clean the battery posts and cables. Reinstall and tighten down. Trace the cables to the other end. Remove them and clean the cable end and its mating surface.

 

it sounds like bad battery connection, clean the terminals

 

I don't have any way to prove this, but I'm thinking that the circuit that kills the power to the lights and other things when you open the door "glitches". It happened twice to my '06, and it happened once to some park visitors. The batteries were in great shape and all of the connections were clean and tight. The only thing that all of these incidents had in common were that the light switch had been left on. I got back in the habit of turning my lights off by hand and never experienced this again.

 

ya, i finally downloaded the wiring diagrams. it has to be the battery, connections, or terminal board where the battery first connects to. i wonder if the door thing would have an effect. idk, it would be a good idea to get a professional battery check, but i know ill never get to it if the problem never returns. ill check the connections in the mean time.

thank you all for your help. i guess there isnt much else to discuss anymore.