the car starts and cuts off the immobilizer is active. What maybe the issue and how can we help solve it

On some vehicles the security light flashes immediately if there is a VIN mismatch or immobilizer issue somewhere.

 

Other vehicles, the car will start momentarily but then turns off due to a VIN mismatch or immobilizer problem.

 

The first thing to assess is whether or not there was any recent changes done to a vehicle. Whether it was an ECU that was replaced or something else. Primarily on most vehicles, the VIN/Immobilizer is stored on the cluster, ECU, Key Fob, Ignition.

 

The next step would be to scan the vehicle for codes with a good OBDII tool that can scan all the vehicle modules to determine which unit is causing the problem.

 

Once the unit at fault is isolated, it'll need to be programmed to the vehicle.

 

Lastly, sometimes it's a low battery charge that can throw the security system off. Have your battery checked at any local auto parts store and perform a hard battery reset.