Disable transponder?

[cabinfevrr]

Hello, I have a 2008 5 door RS, and the transponder / immobilizer is giving me grief. At random, it won't recognize the key, or fight with the Hyundai key on the same ring. It will turn over, start, and then die after 2 seconds. Try a different key, like the valet key, same thing. Take all other keys out of the car to eliminate interference from other chips, it will still do it until it decides to let me drive it. Turn key, fail, take key out, put it back in, fail... When I'm trying to leave for work sometimes it will take 20 - 30 attempts. It's aggravating to say the least, and I won't let my wife drive it right now, lest she get stranded at the mall.

I've searched and can't find anything on disabling or over riding the transponder. I don't need it, I live and work in the sticks, very low car theft area, and have also consulted the insurance company, and they said it didn't matter for a car of this age to turf the transponder.

How do I remove / disable / bypass and still have the car play nice when the key is turned?

[SirDigby]

you would have to change the ECU from a vehicle that is exactly the same as yours minus immoblizer.

[cabinfevrr]

There has to be a simpler way. How do you trick the immobilizer when you have a remote starter?

[CTScott]

There has to be a simpler way. How do you trick the immobilizer when you have a remote starter?

You use a transponder key bypass module, which either requires surrendering a key into a little box that gets hidden under the dash or programming the module by reading an existing key.

[cabinfevrr]

You use a transponder key bypass module, which either requires surrendering a key into a little box that gets hidden under the dash or programming the module by reading an existing key.

Do you think that could solve my problem, or do you think there are bigger issues in play?

[CTScott]

Do you think that could solve my problem, or do you think there are bigger issues in play?

Do you have a second key, as that will tell you if the issue is the key or the transponder key amplifier?

[IllusionX]

Do you have a second key, as that will tell you if the issue is the key or the transponder key amplifier?
If the immobilozer isn't reading the key, it would simply not start the car right? It wouldn't start and die within 2 sec. Once the key has been read and car started, it doesn't need the transponder anymore.

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[cabinfevrr]

Do you have a second key, as that will tell you if the issue is the key or the transponder key amplifier?

I have all 3 factory keys - one with remote, black one and grey valet key. This behaviour is not key specific, it will do this with all 3 keys.

[cabinfevrr]

If the immobilozer isn't reading the key, it would simply not start the car right? It wouldn't start and die within 2 sec. Once the key has been read and car started, it doesn't need the transponder anymore.

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I have a dummy key I got cut just for the doors, and if you try to start the car with it, it will start but after a second or two it will die.

[cabinfevrr]

So other than find an Ecu without the transponder (doesn't exist), and maybe a bypass module would work, no ideas? I can't be the only one to experience this.

[tmontague]

An ecu from an American yaris will work fine as they didn't have an immobilizer on them. You would have to put that ecu in and then disconnect the communication (wires) from the key transponder to the ecu and it would run fine,

Its not an issue I've ever heard of before. If the above is too much work for you then go get it diagnosed at the dealer and they should be able to let you know what is faulty and what needs replacing plus the cost

The reason it isn't easy to by pass is because it is an anti theft device. If it was easy to by pass then it would defeat the purpose of it being there. Unfortunately this men's you have more of a headache to deal with now

[jra]

More of a make money for dealers device than anything else.

[B.B._07]

So other than find an Ecu without the transponder (doesn't exist), and maybe a bypass module would work, no ideas? I can't be the only one to experience this.

In Canada the pre 2008 Yaris did not come with an immobilizer, so you could in theory swap in an 07 or 06 ecu and your key reading problems would go away. Since the 06 & 07 don't have an immobilizer than I would think there would be no need to reprogram the ecu to the car but I could be wrong here. Another possibility is that your car "forgot" the keys and they need to be reprogrammed to the car. Not sure if it's an issue with Toyota's but Honda's of that vintage it's a fairy common issue. A dealer level scan tool is needed to reprogram the keys so you need to take it to a independent shop, locksmith or the dealer. It could also be an issue with the receiver around the ignition or the wiring back to the ECU.