My S40 vovlvo has just stopped functioning without anything out of the ordinary beforehand. When I turn the key in the ignition it doesn`t start at all. Just nothing, no sound, no any other reaction from mthe car. Could it be the battery or the security system? Thanks for your help.

if the lights and battery light come on but there is no click when trying to start. its more like the solenoid on the starter is not working. if you put headlights on and try to start the lights should go dim (no hid lights/leds) if not then the starter solenoid is not engaging the motor to turn the engine over. also make sure you still have your chip in the key as it could be this as well. if you hear the fuel pump engage then the immobilizer is not on.

With the information you've given, I would be checking the battery and the battery cables. This time of year batteries are known to give up the ghost. But oxidation on the battery cable connections would be high on my suspect list.
Since you seem to be unfamiliar with automotive maintenance, I would disconnect the battery and place it on slow charge. Inspect and clean the battery cables.
After at least 3 hours, reinstall the battery, positive (+) cable first, negative (-) cable last. Turn the key. Good luck.

Some ignition system locks will not release the key unless you push in towards the column while turning further off. It is a safety device to stop in advertent removal of the key while moving. Try that first.

There is a sensor in the lock cylinder that is probably faulty. The cylinder may have to be replaced and rekeyed to fit the car.

The 2003 Sonata is equipped with a 'starter KILL' burglar alarm system with disables the starting system (using a N/C 'contacts' configuration instead of a N/O contacts configuration). N/C=Normally closed, and N/O=Normally open contacts. When the alarm goes off with a MY Sonata, the only way to DISARM it is with the key fob (remote) originally programmed for it (unless you purchase a new remote & have it programmed for the vehicle at an authorized Hyundai Service Department). NOTE: So long as the keyless entry & burglar alarm system is functioning/operating normally, the alarm will keep going off and the STARTER KILL function will still prevent you from starting the vehicle. One option is left without purchasing a new remote and having it programmed.
1. When the alarm goes off, get into the vehicle and insert the ignition key into the ignition.
2. Turn the key to the 'RUN' position (NOT the ACC position) and wait for the alarm to STOP (usually about 3 to 5 minutes).
3. The engine should then start using the ignition key.

If this procedure doesn't work, the problem will need further diagnosis by a qualified/certified Hyundai Service Technician.

Hope this helps

Lots of people experience this problem and google provides several links to answers to it, but here is my take on it. The contacts in the gear selector mechanism can trigger this fault code. Put the key in the ignition, foot on the brake pedal, without starting the car, move the gear selector from P to L 10 or so times. This will clean the contacts. Turn key off. Start the car. On my S40, I have to drive it about 10 miles before the arrow light goes out. If it doesn't, do the procedure again to clean the contacts. It sounds crazy, but the process actually works.

hi, sometimes this is easy. put key in ignition turn key to IGNITION. DO'nt START IT. leave ignition ON for 3 seconds. then turn OFF . take key OUT of IGNITION wait 3 seconds and replace ignition key turn key to ignition. this is key recognition. some cars do and some cars do'nt. try this. gerry

thats because your regular key probably has an electic connection to the car so go to your volvo dealer and they should be able to clear anything up or replace it with a key that will work

The swich that you press when you want to change the gear mode("p" to "d" ) remain jam very coomon for an s40 spary silicone spary on it to remove dirt from there