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Auto Doctor: No fix for constantly shifting GM vehicles

The 2012 Chevy Equinox is one of several

The 2012 Chevy Equinox is one of several six-speed transmission GM vehicles that has shifting issues. Photo Credit: General Motors

Dear Doctor: Do you have any experience with the 2012 Chevy Equinox? I purchased one new and now have less than 6,000 miles. My problem is the 6-speed transmission is constantly shifting up and down, especially driving around town. The dealer said this is normal, but it is driving me crazy. Have you heard of any similar complaints? -- Paul

Dear Paul: You are not the first owner to be concerned with the constant shifting on some GM vehicles. There may be an additional software upgrade in the future to lessen the shifting. As of now there are none. You can keep in touch with the dealer for any reprogramming information.

Dear Doctor: I own a 2005 Lexus ES 330 with 45,000 miles. The dealership has serviced my car according to the service manual since day one, and now they tell me it needs a $500 checkup. I'm 83 years old and my funds are depreciating. My son-in-law doesn't think this extended service is necessary. He claims that an oil change (new air and fuel filter) plus tire rotation and balancing for about $200 should do the job. Please advise. -- Libby

Dear Libby: When it comes to needed maintenance each vehicle's needs will differ at mileage intervals. One may require brake replacement and the other fan belts and battery, or suspension work. I suggest you find a qualified shop that employs ASE-certified technicians who subscribe to Alldata and Identifix for service information and technical service bulletins. You may also find the labor rate at an independent may be less.

Dear Doctor: I drive a 2007 Honda Accord with the 4-cylinder engine. It has 75,000 mostly highway miles. I need your advice on changing transmission fluid, coolant, and brake fluid. What would be good intervals for my driving conditions? And are these fluids brand specific? Also, it seems that most shops are "flushing" transmission fluid these days, but the needed frequency is a little gray to me. -- Bill

Dear Bill: The heart of the engine is the oil, as are the fluids for transmission and brake and power steering. We use OEM-brand specific transmission and driveline fluids. Regarding transmission flushing, most import vehicles have transmission drain plugs, so changing the transmission fluid is like changing the oil. I like to change the fluids at 30,000 miles. This may seem early, however, I feel the small expense is well worth it. Spark plug replacement is very simple on a lot of vehicles, especially 4-cylinder engines. Most manufacturers recommend 75,000 to 100,000-mile replacement intervals.

Dear Doctor: I have a 2003 Nissan Altima that has little or no heat at idle. The thermostat was changed and the coolant flushed at the local repair shop, but made no difference. The car was back a second time and I was told they followed Nissan Bulletin NTBO2-047c. Could there still be air in the system? -- Paul

Dear Paul: The first step is to check the engine temperature, followed by a check of the heater hoses going into the heater core with the engine at idle and the blower speed on medium. Both hoses should be the same hot temperature. If one is cold then there is a circulation issue. If both hoses are hot, then the problem is in the heater box blend door operation. I've seen air trapped in the heater core, blocked heater cores, worn water pump impellers and partly blocked radiators cause these problems. I've also found air pockets in cooling systems, too. The average hot heater air temperature on medium speed should be 125 degrees or higher.

Dear Doctor: The instrument panel on my 1998 Dodge Intrepid is going crazy and I'm getting a "no bus" code. It all started when I disconnected the burglar alarm because I lost my remote control. My son looked up the "no bus" on his computer and read that if you disconnect the negative battery cable then reconnect it the no bus would disappear. This worked for a while but then its back to square one. I will be grateful for your advice. -- Roy

Dear Roy: You're not alone with dash cluster problems. The "no-bus" code can be a number of problems, including a faulty dash cluster, faulty body control module, or any module or controller connected in the bus line. If you attempt to troubleshoot the problem yourself, then I suggest you buy a subscription to Alldata. You will find step-by-step information and location of all the modules in the bus line and wiring diagrams, as well as voltage specs.

Junior Damato is an ASE-certified Master Technician. E-mail questions to Mail questions to: Auto Doctor, 3 Court Circle, Lakeville, MA 02347

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