Hi,

This morning when I got to work and I went to lock my car with the keyless entry remote, nothing happened. I made sure all my doors and trunk was closed, and tried again, but nothing works. Neither the lock or unlock buttons on the keyless entry remote worked. The light on the key itself does light up when I push on either the lock or unlock button. Can it still be a low battery on the remote? But I got my scion tc in July 2004, can battery be low already?

Thanks,
Kelly

 

there are two things i can find wrong with your keyless entry..

one: working on military base (i used to work miliatry and on base they occasionally have weird rf signals thrown about which will prevent me from using my remote)

two: all you gotta do is reset the ecu... it may have gotten confused... disconnect battery for a few minutes, and then try it again.

if your key lights up.. it's not the battery in the key.

tell me how that goes.

 

i can bet the battery is weak, almost two years is long enough. even watch batteries don't last forever. and the're 2-3 bucks at any store

 

The fact that the light is blinking means the battery is probably not dead even though our keyfob batteries are tiny.

And the RF Jamming SquallLHeart talks about is true, although it can happen from any other Fob in the US as they are all on the same frequancy.

Try putting the key in the ignition, then take the key out and try to push buttons.

Resetting the ECU will only help if the module is stuck and frozen. (bad thing for it to do) You can test if its stuck by using your second key, if that doesnt work the module is stuck.

If you reset the ECU, have placed the key in the ignition, and it still doesnt work...you would have to look into relearning you keys to the car. (take both keys to your dealer and explain that one doesnt work and you want them relearned.)

BTW, I make these systems for other cars at Work so I should know a little about it. (I didn't make this particular one so I cant say 100%)

 

I'd bet 99% it's the battery. Mine didn't last a year. The light still lit up fine, maybe a little dimmer. As said before, about 3 bucks at most any store.

 

replace battery...

 

well.. i had a customer come into Scion for service with the same problem.. except that he had a CEL thrown as well..

after figuring out his CEL was on due to him forgetting to tighten his gas cap, me and my friend proceeded to troubleshoot the keyless entry..

after disconnecting his car battery and reconnecting it.. it worked... all we did was reset the ecu. nothing else. at least try that first.. it's not hard at all to do.

 

Just because the light lights up does not mean the battery is fine. It takes less energy to light that led than it does to transmit a signal. Once the signal is weak enough to fall below the noise floor the reciever will have a tough time recovering it. I would simply try replacing the battery before doing anything else.

Resetting the ECU is also a quick an easy thing to try, so even if it isnt the cause it cant hurt to try it.

 

Thanks everyone for your responses and help on this issue.

So after I came home from work, I tried the second key I had for my scion, and it works, the car unlocks and locks. But then I tried the original one that didn't work that morning, and it works. So weird, so I dunno what cause it to not work in the first place since it's suddenly working now.

Thanks again for the help! :D

 

MOST LIKELY IS THE BATTERY ......

 

I acutally had the same issue..
After testing (with an actual watch battery tester) and replacing the battery the same problem continued on top of that, the initial (bad) battery wasn't even on low (so I just kept the "bad" battery in since neither the new or old worked afterwards)..
After that process, I located my spare key and utilizing its remote access @ the same time I pulled out the non-functioning key and attempting the same with NO luck...
The weird part was once I was inside my car with both keys in hand trying to mess with both of them it seemed to re-establish its own signal and has been working ever since..