Transponder or security system problem

You presumably refer to the ignition lock barrel, around which is an antenna and a key with a transponder coded to the same code as the security system must be in close proximity before it will disarm and allow the engine to start.

the original key is coded to your car.
So changing the barrel to have a new key wont help and ill tell you why.
Inside the original key is a transponder chip that is programmed to the cars immobiliser unit.
Attached to the ignition barrel is whats called a reader coil and its job is to read the keys chip when inserted in the barrel to deactivate the immobiliser so that the car will start.
What you need to do is contact a good knowlegable locksmith to provide a new key and code it to your car

It is not a stand alone unit. Is built in to the bcm/ecm

i presume you mean the key transponder module for the security system, the system comprises of a key module/antennae module whitch is around the ignition barrel, this communicates with the instrument pack which is the brains of the p.a.t.s. security system, information is then sent around to the cars other modules, ie engine control module via the can network to say ok to start or this is not my key so dont allow to start. what is the nature of your problem? is the pats light flashing?

The security light flashing is the indicator. The fuel pump is disabled by the ECU because the immobilizer system does not recognize the transponder chip inside the key.

There could be several causes.
a. Either the transponder chip inside the key is bad, not programmed, or missing
b. The antennae that is located around the ignition lock is bad and/or not reading the transponder chip inside the key.
c. There is a wiring issue between the ECU and antennae.
d. The ECU is bad

You may want to seek out a qualified mechanic or automotive locksmith for help, not all mechanics and/or locksmiths are capable of handling the immobilizer systems on these vehicles. So be clear when discussing your problem to them and make sure they are capable of handling this type of problem.

If the key is not original, check to see if it is a cloned key. Some cloned keys use batteries, when the battery inside the key dies, it no longer communicates with the vehicle. Although it's not common, regular transponder chips can go bad, usually due to physical damage.

An immobilizer transceiver coil tester can be used to test the signal from the antennae at the lock cylinder.

If the ECU is determined to be bad, a used ECU with matching part numbers can be used as a replacement. Contrary to what a dealership or some shops may tell you, all that is required is an immobilizer reset service on the used, replacement, ECU to get it to function with your vehicle. A used ECU and an Immobilizer Reset Service is much cheaper than a new ECU from the dealer. Make absolutely sure that this is the problem before going this route though.

It's impossible to start the engine without the transponder chip inside the key.. Only way is to buy a new same type key n virginize ur ECU n reprogram ur ECU to recognize the new key unless u still keep the original master key to activate the add key for slave key.. Look for lock smith will do the job.

This is an (almost) impossible task. The immobiliser ECU which reads the key communicates with, and is controlled by, the engine ECU.
It's not possible to just "bypass" the system.
I said "almost" impossible because with the right tools, knowledge and unlimited time it may be possible to capture the code of a useable system, then design and build a black box to respond correctly to the engine ECU, which would allow engine operation.
If you have lost your only usable key, you need to order a new one (as you haven't indicated your exact model, I can't give you the correct part number - keys are different depending on model/engine).
You will also need a dealer who can programme a new key to your existing vehicle.
If your existing vehicle has problems with the immobiliser, you may be able to find a Toyota dealer to interrogate your OBD to see what the issue is. If not, replace the key transponder unit, then the ECU.
I've assumed you know it's an immobiliser issue, and that you've done the usual wiring and fuse checks etc.

Yes, you have PATS II. There is a tranceiver on the ignition barrel and a transponder in every factory key. If the transceiver cannot read your key, the red security light will blink rapidly.If this happens, make sure you are using a factory key and there are no other factory keys near the switch. If it continues to blink rapidly, you might try removing the PATS ring from the key barrel and placing a factory key in the center of the ring. I have done this successfully in the past. If it works, tape up the key inside the ring and place it in the open space in the steering column shroud. Then remove the transponder from any other factory keys. You can then have keys made at a hardware store, as your one transponder inside the column will constantly respond to the PATS system.

Hello I happened to me a problem in my car check in the computer system and Dahr me On B2799 So how fittest Alco possible Chrahola Hza case and thank

Sure, I would sell you the same parts, IF I was interested in robbing you, BUT, I have no interest in having dissatisfied customers...So, here is what I need you to do: Call this number: 1-877-517-LOCK
This is my local locksmith,and he is cool...Tell them that I gave you this number. He has a machine, on his truck, that will reprogram your key to match the ECU/barrel combo in your car. Now, I do not expect you to have him come to your location, but, he may give you the info that HE has, his machine, and then you could call local locksmiths to see if they have the same gizmo that he has, to solve your problem. Secondly, there is an ECU exchange program from Toyota, that your dealer ssomehow neglected to tell you about, but it would cost you about 700.00 to get you going. Call the locksmiths first, and get back to me if my guy won't help you. This is the best that I can do, up to this point. Hope this helps. Advise of what transpires.