Auto Scanner: Engine light means car won't pass inspection
By Larry Rubenstein Correspondent
Q: My daughter has a 2003 Cadillac Seville. It just began to show a nonemission code which, according to her mechanic, reads clutch converter on the mechanic's code scanner. I know you are a Massachusetts businessman, but I was wondering if you knew whether that reading is enough to get her rejected in New Hampshire, and how expensive is it to repair. She had a 12 month/12,000 mile warranty that has expired due to it being over on the mileage. She bought the car used from a Nashua, N.H., Cadillac dealer and she is reluctant to take it to him for fear of being overcharged for the repair.
A: I have spoken with an associate in New Hampshire who assures me if a car has a check engine light on for any reason, the car will not pass a state inspection test. With concern to the transmission on your daughter's car, I have brainstormed with my good friend, Mike, at a transmission repair shop. He has indeed seen this problem many times and repaired quite a few of these Sevilles. Since you did not include a trouble code number associated with the check-engine light, we can only presume it's in the 740 range. That being said, the code is telling you the transmission is slipping, which is causing your fuel mileage to drop. In most cases, the transmission slip is too slight for the average person to feel when you are driving, however, your fuel mileage will reflect this problem, and it can usually only be seen on a computer scanner. In most cases, this transmission repair will cost anywhere from $800 to $1,300 for parts and labor.
Q: I have a 2003 Chevrolet Astro minivan with a V6 engine and automatic transmission. It repeatedly develops a tendency to stall without warning, usually after a stop. Replacing the distributor cap and wires cures it, but for only a few thousand miles, then it starts stalling again. We have done this at least five times. On our most recent trip to the dealer, he suggested that the oxygen sensor would most likely cure it. (No codes get stored.) We replaced it and we had good luck for about 2,500 miles, but now it is stalling again. Any ideas?
A: With the information given, I have to rely on experience. The fact that no code is set tells me even further that the oxygen sensor is not the problem. There is a chance you are using poor-quality parts, which would account for the problem happening in a period of time after the repairs have been made. My experience with the Astro tells me you have a problem with the idle air control motor. This little device has to rapidly meet the idle desired when you take your foot off the gas. This really should not be that hard to diagnose and hopefully not too expensive to fix.
Car Care Tip: A transmission that has not been serviced in at least 25,000 miles could have an indiscernible slip to it, costing you miles per gallon of today's very expensive gasoline.
Larry Rubenstein is a master technician who owns a North Shore service station. His column appears Tuesday in BizNorth. Write to Larry c/o BizNorth, 32 Dunham Road, Beverly, MA 01915, or send e-mail to scanauto@aol.com.
