While driving lately the car keeps cutting out. at that time no warning lights, today car wont start and the system immobilizer warning light is now on and wont turn over.What is this?

Security system failure is a common problem on GM vehicles. Every time you put your key in the ignition, the vehicle's security system reads the signal from your key to make sure it is OK to run. When it receives the "correct key" signal, the security system allows the starter to turn over, and/or the fuel injectors to function and your car works like it normally does every day. If you were to use a different key, or try to hot wire it, the system would shut down these parts of your car, thus making the vehicle completely immobile. This is GM's way of preventing vehicle theft. The problem is that the system is known to fail quite commonly. It has been failing consistently for around 30 years. When it fails, two things can happen. First, you turn the key and nothing happens at all. Lights work, radio works, windows work... just not the starter that you need to start the vehicle. This is a "starter immobilizer". Second, you turn the key and the vehicles starts just fine, but then stalls in 2-5 seconds. This is a "fuel immobilizer". It literally cuts off the fuel injectors and stalls the vehicle to immobilize it. These are normally, but not always followed by a light on the dash that says SECURITY or ANTITHEFT. These lights are to inform you of the system's failure to collect the information it needs from your key to the computer. If your security/antitheft light is on, odds are you will be stranded soon, if not already. Remember that the security system controls the security light. If the system is failing, the light may never warn you of the failure. http://vatspasslockpasskeysecurityhelp.yolasite.com/

Antitheft or Security system failure is a common problem on GM vehicles. Every time you put your key in the ignition, the vehicle's security system reads the signal from your key to make sure it is OK to run. When it receives the "correct key" signal, the security system allows the starter to turn over, and/or the fuel injectors to function and your car works like it normally does every day. If you were to use a different key, or try to hot wire it, the system would shut down these parts of your car, thus making the vehicle completely immobile. This is GM's way of preventing vehicle theft. The problem is that the system is known to fail quite commonly. It has been failing consistently for around 30 years. When it fails, two things can happen. First, you turn the key and nothing happens at all. Lights work, radio works, windows work... just not the starter that you need to start the vehicle. This is a "starter immobilizer". Second, you turn the key and the vehicles starts just fine, but then stalls in 2-5 seconds. This is a "fuel immobilizer". It literally cuts off the fuel injectors and stalls the vehicle to immobilize it. These are normally, but not always followed by a light on the dash that says SECURITY or ANTITHEFT. These lights are to inform you of the system's failure to collect the information it needs from your key to the computer. If your security/antitheft light is on, odds are you will be stranded soon, if not already. Remember that the security system controls the security light. If the system is failing, the light may never warn you of the failure. There is a lot of info on this site that you can read up on. http://vatspasslockpasskeysecurityhelp.yolasite.com/

Never ignore warning lights. The spanner light is the cpu telling you that maintenance is required on the engine. Suggest you have the fault codes read asap. It could be that the timing belt has to be replaced.

Here is a fix >

Security and Immobilizer System Indicator Symbols Symbols & Tell-tales
These are Security and/or Immobilizer System Indicator symbols used by manufacturers. One of these symbols lights momentarily to indicate that the ignition switch is locked and will need the proper transponder-equipped key to re-start. The vehicle is immobilized otherwise. Green symbols will flash when the vehicle is immobilized.
If the symbol is visible when the vehicle is on, it indicates a malfunction in the security system. If the engine does not start with the correct key, and the security indicator remains on, the system may have a malfunction. You will need to contact your dealer in either case.
Keep the Symbol meanings with you!

These problems can cause by several different reasons,
Engine needs air-fuel and sparks to keep running.
Ignitions and fuel system inspections will be good place to start and if you have any engine warning light on your dash the best thing to get the code read out to get first idea what is causing the problems you have!!

You could be experiencing some security system issues. The security / anti theft that GM puts on its vehicles are an immobilizer type. They turn off starters and injectors, sometimes more. You could be right on the edge before complete failure. Check out this link for info and some DO IT YOURSELF solutions. http://vatspasslockpasskeysecurityhelp.yolasite.com/

have scanned if light is on. it may be a bad or failing crank sensor. for the sensor controls timimg, it will stop engine while driving. have a good day!!

OK, if the vehicle won't start and the service immobilizer light is on then I would definitely take it to the dealer in order to have the key programmed to the computer, again.

Did the battery go dead lately? Is there a code associated with it not starting, as in the immobilizer function lamp?

or the key is not programmed to the ecm?

P0633 Immobilizer Key Not Programmed ECM/PCM
This is just a possibility to look into.

The ignition key may be defective or in need of a battery to generate the code needed to disarm the immobilizer. Hope this helps!

could possibly be a flat battery possible could be the starter motor also when you unlock the car with the key the immobilizer should of disarm