The security light isn't coming on even though I already changed the thing that reads the key. And my car won't start.

It is standard practice with lots of modern cars to leave the ignition key in and turned to the on position when connecting a battery as this helps prevent alarms sounding, immobilisers engaging and all sorts of inconvenient stuff happening. It is even better to use a memory saver while changing a battery so not even the radio code and stations are lost.

You didn't say how long you have owned the car. If it was a recent purchase it should have been returned to the dealer as soon as you realised the battery was faulty. There is such a thing as warranty and consumer rights. The dealer certainly should not have sold the car with a defective seatbelt.

It certainly seems like the security system is activated though the presence of the key in the ignition should deactivate it if it is working ok so maybe it is broken or maybe it has forgotten the correct code and needs reprogramming.

It is possibly a coincidence and there is a fault, perhaps caused by the first mechanic. Before towing the car to the Suzuki dealer or calling for an autolocksmith it would be a good idea to physically check voltages, wiring, the presence of fuel and injection pulses, spark and suchlike. If all seems well under the bonnet the chances of an immobiliser malfunction are quite high. Reading the vehicle handbook is always a good place to begin.

I can understand you being frustrated.
There really is no way to tell if the fuel pump was the problem at this point.
If the security system fails, you should see "security" light up on the cluster.
The key lock has a sensor that reads the chip in the key. If the sensor fails or the chip fails the computer won't let the vehicle start.
Most of the time when the security system is at fault, the vehicle won't start, but it won't cause the engine to stall.
You might want to have someone check the fuel pressure and spark at the plugs if you don't see the security light on the cluster.
Could be the fuel pump relay and a list of other things.
I would probably check the computer for trouble codes too.

mine does the same thing, but my security light flashes. I was told that it is the security system on the car not recognizing the key. The key I am using is the original key for the car though. I was told that a quick (but not so quick) fix is to open the door, put the key in, turn it on but don't start it.... set for roughly 10 minutes so the car will reset itself. It works everytime but is a pain in the ****. Was told the only way to completely fix the problem would be to put a new motor in it.

security light comes on if the chip in your key isn't reading.. Possible issue are the pickup in the key cylinder is getting old and weak. a resistor that matches the reading of your key can be added to the bottom of the steering column where the orange wiring goes into a two pin connector and it will allow yo o bypass the security so it will start

YEP IF YOU SEE SECURITY LIGHT FLASHING YOUR CAR IS IN THEFT SECURITY MODE WHICH WILL SHUT DOWN FUEL SYSTEM. HAVE VECHICLE CODE SCAN PROBLEM IN THE BCM MODULE.IT WILL TURN OFF FUEL IF IGNITION KEY HAS IN CORRECT RESISTANCE OR KEY WORN OUT.MAKE SURE YOU HAVE FACTORY IGNITION KEYS.DONT GO TO HARD WARE STORES GET EXTRA KEYS MADE.BECAUSE IF BCM ECM AND IMMOBILIZER CANT READ KEY CODE RESISTANCE WHICH NOT IN A REGULAR KEY IT WILL SHUT DOWN FUEL SYSTEM AND CAR WILL GO IN THEFT SECURITY MODE.YOUR PROBLEM IS DEALERSHIP FIX.

Check the battery voltage with a multimeter. If the battery can't deliver a full 12 volts, the starter solenoid won't even activate. It may be that a cell went dead, causing a direct short inside the battery. Replace the battery if your battery is older than 3 years, or take it to an auto parts store to have it tested. The security light on is an issue many people have when the battery is low and the car won't start.

It is also possible that the security chip on the ignition key is worn. If it isn't making contact properly, the computer won't 'read' the resistor, and won't start. You will need to replace the key to see if this fixes the problem.

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Those has every thing to do with it. You'll find the answer you need though this link. Comment back if you have questions http://vatspasslockpasskeysecurityhelp.yolasite.com/

If the security light is on, then it can only be one thing. The security system is failing and immobilizing your car. Go to this link and read up on the problem. The security light is a dead give away that the security is messed up. If you have no little black chip in the shaft of your key, then this means you must have a passlock that runs on the transponder. You need the PERMANENT fix from this site. http://vatspasslockpasskeysecurityhelp.yolasite.com/

On the older fords the theft module has 2 plugs in them. You can disconnct one of them, I believe it is the right one , and disable the security system. Finding the module is the hard part. most are located in the middle of the dash.

turn key on for 10 minutes until light stops flashing then try to crank car over