If the light is not coming on when you turn on the ignition, check the bulb, it may be blown.
Simply turn on the ignition but do not attempt to start the engine. If the light bulb is good you will see the Check Engine light illuminate and stay on. If you do not see the Check Engine light, the bulb is defective or has been removed.
If you turn on the ignition without starting the engine and the Check Engine light does not come on, the bulb has burnt our or has been removed. Replace the bulb.
Do you mean the check engine light does not come on when you turn the ignition on? Possibly the bulb is burnt out.
The light should be on before starting, and for 3 seconds after starting, as a bulb check.
When you turn the ignition key to the run position just before starting the vehicle the check engine light will light for a few seconds to check the bulb
bulb no good.
Right there in the instrument cluster. Turn on the ignition switch but do not start the engine. The check engine light will stay on. If you do not see it then the bulb is burnt out or has been removed.
When you turn the ignition key to the run position , just before starting your Explorer , the check engine light should come on for a few seconds to prove that the bulb works
It is a possibility that the Airbag light does do a self diagnostic (Most cars do), and that it does not come on is because the bulb is burned out (The reason self-checks are performed). Check the bulb first, or try replacing it with a known good bulb, then try it again.
When you turn on the ignition switch the check engine light will come on for a few seconds. If it does not then the bulb is burnt out or has been removed. As you failed to list make, model, and year it is impossible to answer your question.
Turn on the ignition and do not start the engine. The light will come on unless the bulb is burnt out or someone has removed it.