The ignition lock assembly, also known as the ignition lock cylinder, is the cylindrical tumbler that is used to turn on and start the vehicle when the key is inserted and turned. While many newer vehicles are now being manufactured with push button or keyless starting systems, traditional tumbler and key ignition lock assemblies are still commonly found on many road going vehicles. It is usually located on the steering column, to the right of the steering wheel.
The ignition lock assembly functions in a similar manner as a regular door lock assembly, however instead of locking and unlocking the doors, the ignition lock assembly is used to power on the vehicle and start the engine. The assembly is matched with a specific key that will turn in the cylinder, and has different positions of the key that will do different things. Most ignition lock assemblies have four positions, the first unlocks the steering wheel, the second powers on the vehicle’s accessories, the third powers on the vehicle’s fuel pump and engine management system, and the last cranks the engine.
When the ignition lock assembly has issues it can cause problems with powering on and starting the vehicle. Usually a bad or failing ignition lock assembly will produce a few symptoms that can alert the driver of a potential issue.
1. Issues powering on the vehicle
One of the first symptoms of an issue with the ignition lock assembly is problems powering the vehicle on. Over time, as the ignition lock assembly is repeatedly turned every time the vehicle is powered on, it may eventually wear out. This may lead to one or more of the positions having difficulty properly engaging, and in turn may lead to issues with powering on the vehicle. A worn ignition lock assembly may fail to power the vehicle on when the key is turned an inserted, or may require the key to be jostled for the position to engage properly.
2. Car is not starting
Another symptom of an issue with the ignition lock assembly is a no start condition. The ignition lock assembly is usually connected to a an electric ignition switch. The two are interconnected, and work together to power on the vehicle and start the engine. Over time the ignition lock cylinder can wear and eventually break. If it breaks and is unable to turn the ignition switch, this will result in a no start condition due to the inability to provide power to the starter.
3. Problems inserting or removing the key
Problems with inserting or removing the key are another symptom of an issue with the vehicle’s ignition lock assembly. Over time, as the key is repeatedly inserted, removed, and turned, both the cylinder and the key will eventually begin to wear. A worn key or ignition lock may result in difficulty turning the key when it is inserted. The worn lock or key may cause the lock assembly to jam when the key is inserted, and may bind when attempting to turn the key. A worn cylinder or key may also cause the assembly to jam or stick when attempting to remove the key. This may also lead to issues with unlocking the steering wheel when first inserting the key.
While newer vehicles are starting to utilize keyless, push button symptoms, ignition lock assemblies are still commonly found on the majority of road going cars and trucks. While replacing the ignition lock assembly is not generally considered routine service, if you suspect that your ignition lock assembly may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the ignition lock assembly should be replaced.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Ignition Lock Assembly and was authored by Eduardo Ruelas.