Q: I have a 2004 Chrysler Sebring convertible. Approximately three or four months ago, the seat belt warning light came on and stayed on for a short time and then went off and stayed off for a short period and now it came back on. Is there an easy fix for this problem, such as a fuse, or is this something that will have to be addressed by a dealer? I don’t understand why it goes off and then comes back on.

A: Your seat belt warning light is commanded on by the air bag LED warning control circuit within the instrument cluster when it sees a closed driver’s side seat belt buckle switch. The buckle is part of the seat belt tensioner, which contains a pyrotechnic device and mechanism that almost instantly snugs the seatbelt during a crash. This can help prevent occupants from sliding beneath the seatbelt and helps to keep driver and passenger in the best position for airbag deployment.

Did the seatbelt warning light illuminate or go off while driving, with the seat belt already buckled? Or perhaps it remained on for an entire driving session, but not the following day? If the first case, I’d suspect a possible connection fault in the seat belt sensor circuit connector beneath the seat or the buckle switch. In the second case, perhaps foreign debris within the buckle cavity is confusing the switch or wear within the buckle is causing intermittent switch function. Try inspecting, and perhaps vacuuming the buckle cavity, and exploring deliberate movement of the buckle connection with one eye on the light.

The tensioner/buckle assembly is a fairly pricey part. If you are unable to find relief by cleaning the buckle cavity, I found a place that repairs tensioners for about $60: Safety Restore, at 855-552-7233 or www.safety restore.com.

Q: I own a 2008 Chevrolet Equinox. After owning it for about two years, using the same gas, the “check engine” light kept turning on and off for several days at a time. The Chevy dealer said the scan indicated lean fuel. I tried higher octane. I began using Chevron gas, and the problem remained. I had the Chevy service department look at it and they again said the diagnostic code indicated lean fuel. The light continues to turn on for two or three days and goes off for two or three days. Any suggestions?

A: It’s the Chevy, not the fuel. Were there two codes, P0171 and P0174? This could be caused by a contaminated mass air flow sensor; air leak in the mass air flow duct; vacuum leak; low fuel pressure; or restricted fuel filter. If only one of the two codes is present, the cause may be a faulty oxygen sensor, dirty fuel injector, vacuum leak, misfire or exhaust leak on that cylinder bank.