My 2013 toyota tundra won't start

A few days my truck wouldn't start. (It's for sure not the alternator) So I did the basics and checked for voltage on my battery and checked if the fuel pump was Turning on and both those things are good. When I turn the key over it sounds like it's suppose to. No odd noises or anything abnormal at all. I also checked to see if the engine was getting fuel and it was all checking out. I then went to the fuse box and switched some relays around and eventually one combination worked and the truck started. It started up multiple times the following day and it was all good. The next day I went to start it and the same thing happened again and it wouldn't start. It could be a bad fuel pump module but those aren't cheap, but I think something is frying the relays. Anyone got any info that could help me out?

 

Is the security light on the dash turning off completely and staying dark when you turn the key on? Have you tried a second key? Both of these help verify its not a security system issue.

Would help of you could provide which relays you think are going bad.

 

I ended up getting another key and new chip and it started up. I'm fairly confused why that worked but it did. Thank you

 

The key has a passcode built into it. When you go to start the truck, it looks for the passcode from the key. If it cant see it then it doesn't allow the truck to spark/inject fuel. It thinks you are trying to steal it because you don't have a proper key (that it recognizes).

I think your original key will have to be replaced if its starting to fail. The passcode is passive and doesn't use a battery.

If a good key is inserted, the red flashing security light on the gauge cluster should good off and stay off. If the key is in the ignition turned on and the red security light is on or flashing the truck doesn't recognize that key and will not start.

 

Great explanation