Power Modules Experience Confusion with Changed Battery

December 4, 2010/Steve Tackett

MOTOR MATTERS ASK THE AUTO DOCTOR BY JUNIOR DAMATO

Dear Doctor: I own a 2003 Cadillac CTS with only 27,000 miles. I recently replaced the battery and encountered a problem with the power windows. When I push the power button to have the driver’s window go down, the passenger’s window also goes down. The same happens to the rear windows, too. They all worked fine before I replaced the battery. What is making this happen? Will
Dear Will: Most new vehicles have logic modules, body modules and door window modules. These modules are all subject to confusion when battery voltage is interrupted. I looked on our Identifix web site and found the same condition noted from another technician. In this case he disconnected the battery for one hour. This resolved the problem.
Dear Doctor: I have a 2000 Nissan Altima that developed a dash cluster problem two years ago. When temperatures dropped to 50 degrees while driving in stop-and-go conditions with the heat on at the maximum settings and blower on high position, the dash lights went out. Then the engine bucked and stalled. The MIL lamp came on and the dealer found trouble code PO500. They replaced a VSS sensor and recommended a new instrument cluster. I opted at the time for a used cluster and it was fine for about two years — until presently. The lights go out and stay off for 15 minutes (but this time no bucking and no MIL light). Is there any advice you can give me on this? Kris
Dear Kris: Electronic dash clusters are more common than ever and as cars equipped with electronic dash clusters start to age these units will beak down and need repair. Getting a used dash cluster will not work in all vehicles. Some vehicles need to have a dash cluster programmed to the vehicle with the correct mileage, VIN number, and other pertinent factors. When I have a vehicle with a dash cluster problem, I opt to send it out to a specialty shop and have the original unit repaired as opposed to using a replacement unit (which are rebuilt as well).
Dear Doctor: I own a 2007 Ford Focus with 80,000 miles. Recently, I’m having a very hard time putting gas in the tank. The gas pump keeps shutting off. The shop pulled out the gas tank and fill tube, but could not find any problems. Do you have any ideas? Ann
Dear Ann: Yes, I see this problem often. The first time I ran across this problem I checked the Identifix web site and followed the testing to a faulty canister vent solenoid. The local Ford dealership had a few in stock. When removed for checking, the solenoid should be open. If the solenoid is in the closed position, then it is bad.
Dear Doctor: I recently purchased a new 2010 Camry with four-wheel disc brakes.

I noticed the rotors looked rusted. The car stops well. Then I saw another car parked next to me in a parking lot with the same rusted rotors. Can I assume this is common with all cars? Ira
Dear Ira: Brake rotors will rust under certain conditions, especially when they get wet and the car is not driven often. Some rotors will rust and take more driving to clean the rust off. After a car wash it is always advisable to drive the vehicle a few miles to dry off both the brake rotors and pads. The rust is more often than not a very normal condition.
Dear Doctor: I always read your advice column and would like your opinion on the new 2011 Buick Regal CXL. I understand the car only has a four-cylinder engine. What is GM thinking? Steven
Dear Steven: When the 2011 Regal arrived a few weeks ago and I popped open the hood I also wondered why a four-cylinder was put in this Buick. Our test car had the 2.4-liter four-cylinder coupled to a six-speed transmission. To my surprise, the new Regal had ample power at all speeds, due in part to the six gears and the efficient Ecotec dual overhead cam engine. Gas mileage combined city/highway was in the mid 20s. The base price was $26,245. I never did feel the car was underpowered. If you want more power, wait for the Regal turbo model due out soon. — Junior Damato, Motor Matters

Junior Damato is an ASE-certified Master Technician.

E-mail questions to info@motormatters.biz

Copyright, Motor Matters, 2010

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