Most drivers think of the ignition switch as the slot where they insert the key to start their car, but that’s actually the ignition lock cylinder.
The ignition switch is a more complex electrical component that has to “read” anti-theft coding in the key before it will activate electrical systems in the vehicle so the vehicle can start or allow an automatic transmission to be shifted out of Park.
On vehicles with push-button start, the ignition switch has to recognize the anti-theft code transmitted by the key fob before it will allow the engine to start. If nothing happens when the key is turned in the ignition lock or no dashboard lights come on when it’s turned to the On position, those are signs that an ignition switch has failed or there’s a problem with the wiring from the switch to the starter or other electrical components.
Those could also be signs of other problems, such as a failed starter motor or a dead battery. Another potential issue is that a heavy key ring can cause wear on the lock cylinder and the ignition switch, allowing the switch to turn to the Off position when a car hits a bump or pothole, disabling the power-steering, air bags and other systems.
That’s what led to General Motors recalling 2.6 million vehicles in 2014 to replace the ignition switch, lock cylinder and keys.