Malfunction Indicator Lamp (MIL) aka Check Engine or Service Engine Light

My MIL is lit. Should I get my vehicle repaired before taking the test?

No. Test with your light on first. Repairs done before the emissions test can't get a waiver. You get one free reinspection after repairs within twenty days of the first test so you won't have to pay for the test twice.

What is the MIL?

A dashboard light that comes on when the vehicle's computer finds a problem that could cause excess pollution. Often this means you should repair your vehicle to avoid costly damage in the future.

If the light is blinking or flashing, have your vehicle serviced at once. Expensive damage to the catalytic converter may result if the problem is not fixed. A trained technician should test a vehicle any time a malfunction indicator light is on for more than one month.

Why is it important to respond quickly if the MIL is blinking?

It can save you money. When the light is blinking, the vehicle's computer system found an emissions problem that will ruin the catalytic converter, the most expensive emissions-control part on the vehicle. Early diagnosis and repair can prevent costly repair. Responding to this light quickly will lower vehicle emissions, improving overall air quality in the region.

What should I do if the MIL is on?

If the MIL is lit after many driving trips, then a trained repair technician should test the vehicle. The OBDII System stores information that tells repair technicians what is wrong with the vehicle.

Can the MIL be turned off?

Yes, a qualified repair technician can turn the MIL off following service. Occasionally the vehicle will turn the light off automatically if the initial problem is no longer detected by the OBDII system.