ibjavier

Hello friends. I am having problems with my sister's 2007 scion tC. The car has 59,900 miles on it. I bought it six months ago from a private party and I believe that I am now the third owner.

Last week, the car did not want to start. It was cranking but it just would not turn on. After several failed attempts at trying to start it, we left it alone. We came back several hours later and it started!! So we just assumed that the problem was fixed and thought nothing more of it.

Two days ago, the car would not start again. So immediately I went to check the battery and fuses. Everything is okay. We came back a couple of hours later and it started again. I am assuming that everything else is okay with the car since we can sometimes get it to start. I don't want to drive it around like this because it is not reliable and my sister could get stranded anywhere haha.

My mechanic suspects that it has something to do with the factory alarm. I don't know if ALL scion tc's are like this, but my car will not start unless the alarm is activated prior to turning on the ignition (basically, i have to unlock/lock the doors with the key fob). If the alarm is not activated, the car will not start. Is this some sort of immobilizer? Is this normal? We only have one key so we cannot try a spare. The alarm appears to be functioning as I am able to lock and unlock the doors; I even see the lights flash when I activate and deactivate the alarm. Is it possible that the key fob battery is dying and this is its way of letting me know to replace it? What will happen when my key fob battery dies? Will I not be able to start my car anymore? I need to resolve this today because the street sweeper passes on my street tomorrow lol. Thanks.

LEDeZ

If it is factory it should not be doing that. Immobilizer prevents from starting if the alarm is activated.

Are you sure if you have an alarm? To check,roll down the windows, lock the doors. Wait 30 seconds. Open the door from the inside. You'll then know if it has alarm.

ibjavier

I want to update everybody on the status of my problem. I took it to the dealership and it turns out that the EFI relay needed to be replaced.

I was charged $240 including parts and labor. While I was there I got a spare key for $140 (key $65, programming $75). I got the key without the remote (no lock/unlock buttons).

EFI relay. There is no explanation as to why it went bad. I hope this can help somebody in the future.

I am glad the car starts now every time. By the way, my car has no alarm. I locked the door and opened the door from the inside. There was no alarm.