"Start prevented, Try again" episode

[brick]

Picked up an '05 a few weeks ago, and it's been a dream without a hitch. Until today.

After I used the car in the morning, I had my wife take it out for the first time. When she used her key (fob, first time hers was used on this car since we got it), she got "Start prevented, Try again" message. I tried using my key with no luck. The valet key that came with the car didn't work either.

It being a Sunday in the USA and no dealer service department open, I tracked down the salesman at the dealer. He wasn't able to help.

Internet search turned up many such episodes, which said
- immobilizer antenna faulty/needs replacement
- open/close gas cap
- tap on brake pedal
- jiggle shift lever
- unlock/lock and try again

When I went back to the car in maybe 20-30 minutes to try these suggetions, the car started (with my key/fob) without a problem. The valet key starts fine as well. Couldn't try my wife's key since she left in another car.

Having owned other, older Volvos, I was bracing for oxygen sensor, suspension issues, etc., but not this fear of being stranded (especially for my wife away from home).

When I bought the car, the dealer service told me that the key fob was once replaced. It might have been the immobilizer antenna - I'll have to check again.

So, some questions I have
- Assuming it was my wife's key that triggered the no start condition, is there a wait time before a 'good' key will start the car? I'd hate to experiment with her key. Maybe if I have a day off, I'll run that experiment right outside of the dealer service door, but I don't have that luxury.

- If that is the case, I assume I need to take both her key and the car to a dealer to get it reprogrammed. Is that true, so can I send her key away by itself? The dealer I bought the car from is a bit far, and I know it'll be easier dealing with them than a nearby one. The car is under warranty, but there are some dealers I want to avoid even under warranty if I can help it.

Any other suggestions would be appreciated to put my mind at ease. What do I do to ensure that we won't get stranded? I'll tolerate with CEL, clunking, etc., but no start... This happened one day after the salesman (a good guy) called to see how things were going. I told him I couldn't be happier with the car. Well, spoke a bit too soon.

I read this forum and others quite a bit (too much, I thought) before I bought the car, and I'm surprised that I never came across it.

Thanks in advance.

[brick]

Boy, wife came back and tried with her key again - the car started.

I was so hoping her key wouldn't work so the dealer could reproduce the problem and get the error code. Now we've got an intermittent problem.

For anyone that experienced this, what did you do? What would you do in my situation?

A curious question - reading the manual, it says one of the two master keys is foldable. Is that true? I got two master keys and both are foldable (jack knife style).

[JRL]

Did you happen to have both keys in proximity to each other?
That alone can prevent a start

[uscgc70]

Could definitely be the immobilizer antenna. it's a cheap part and very easy to replace. i would start there.

[brick]

Did you happen to have both keys in proximity to each other?
That alone can prevent a start

No, my wife was alone in the garage, my keys were no where near the car, when the problem first occurred.

She does have a remote for Toyota Sienna in the same key chain, but then I have the same set as she does, so hard to use that as the cause. I haven't had this problem until today, although I bought the car only a few weeks ago.

[JRL]

Well, it's something with the immobilzer.
Sometimes these cars won't start when both keys are on the same chain or close together, they cancel each other out which is why I asked.
I think the dealer has to fix this

[brick]

Could definitely be the immobilizer antenna. it's a cheap part and very easy to replace. i would start there.

I remember reading somewhere that the antenna is ~$100? Or, am I mistaken?

I'd love to have the dealer replace the antenna for the peace of mind. The problem is, the car is under the warranty and I doubt the dealer will replace the antenna when the problem isn't occurring. I tried a few more times since the problem mysteriously disappeared. It starts right up each time, with either key.

The price tag of 'peace of mind'... sigh.

By the way, I did more search while I was typing the above, and one person reported that, after getting his XC towed to the dealer for 'immobilizer alert' (a different message, same symptom), he had it towed to the dealer. The dealer locked/unlocked 5 times in a row with the remote, which resets the immobilizer, and he was on the way.

Now I'm keeping my fingers crossed that I can get the problem occur again, so I can try the above method. If anyone gets no start problem, please try the above and let us know.

[brick]

Well, it's something with the immobilzer.
Sometimes these cars won't start when both keys are on the same chain or close together, they cancel each other out which is why I asked.
I think the dealer has to fix this

I agree 100% that it's the immobilizer. I just don't know how to make the dealer fix it when it works properly.

By the way, JRL, thanks for the time you spend on this forum.

[JRL]

Sorry I can't help you anymore, immobilzers are a nasty issue to deal with and usually only a dealer can help

[tgwillard]

A few months ago the wife called me from work to tell me her S80 would not start. I don't know if she was getting an error message at the time. I remembered reading posts on this site about similar circumstances. I told her to lock and unlock the car and try again. She did and the car started and this problem has never repeated itself. I have heard putting in the key again but turning it 180 degrees might also work. Sometimes these issues can never be replicated, leaving you scratching your head. Or the problem could reoccur tomorrow.