2005 Prius Hybrid Battery Should Be Tested For Voltage

April 3, 2010/Steve Tackett

MOTOR MATTERS ASK THE AUTO DOCTOR BY JUNIOR DAMATO

Dear Doctor: I have a 2005 Toyota Prius that got stuck in traffic on a slight incline. It seems that I can only creep and crawl forward on the battery, and the line denoting battery capacity is getting less and less. I’m unable to move the car forward fast enough to charge the battery. Once the battery is depleted can the Prius move forward on the gasoline engine alone? Richard
Dear Richard: In the case describe your Prius should operate under gasoline power. There have been many updates in the computer programming. I recommend you go back to the Toyota dealer. Another concern is the battery will be going on six years old and should be tested for its ability to store the reserve voltage needed.
Dear Doctor: I recently purchased a 1998 Saturn SL2 with 73,000 miles. It showed a code for “faulty cam position sensor #1”. I changed the coil for cylinders #1 and #4 and the car now runs great. However, I have an intermittent problem with a high idle after the car heats up. Shutting it off and restarting seems to fix it. There are no codes. How can I make this repair? Maureen
Dear Maureen: The idle speed is controlled by computer input. The most common fault is a sticking throttle position sensor and/or lazy idle air control motor. Both items can be checked with a professional scan tool designed specifically for your vehicle.
Dear Doctor: I own my grandmother’s very low-mileage 1989 Buick Skylark Custom with the V-6. It has only 75,000 miles on it. The car runs fine, but will die for no reason and not start again until it sits overnight. It has been to a good mechanic who said it does not need a tune-up, has good spark, as well as good fuel pressure. The Buick passed the California Smog Check, too. I am at a total loss as to why it will run just fine for several miles, die, and then not start again until it sits for a period of time. Robert
Dear Robert: You will need to check the computer for trouble fault codes. The next step is to get the Skylark towed to the shop when it dies.

The best option is to check the engine during its no-start condition. If you cannot make this arrangement, then you can purchase a spark tester and fuel pressure tester. When the car does not start you’ll have to run a test of what is missing. The results will give the technician an area to examine.
Dear Doctor: My 2005 Jeep Cherokee’s horn started to go off on its own. I had an issue with the headlights doing the same thing, so I replaced the directional/light switch and that resolved it. I re-examined the switch (light) connection, but see nothing wrong. Now when I turn the headlights on the horn blows and stays on until I pull the relay. There are times when I turn the lights on that the horn doesn’t go off. Where is the problem? Jack
Dear Jack: When you press down on the horn pad the signal flows through the clock spring, down through the steering column via the body control module, out to the relay and finally to the horn sounder. The first step however, in your case, is to recheck the installation of the headlight switch. Next, use a professional scan tool to examine for fault codes in the body control module. A technician who has knowledge of the electrical system of this Jeep vehicle should do the diagnostic tests.
Dear Doctor: I purchased a 2008 Lexus with only 10,500 miles. When I drove to Florida the left front end would vibrate up and down during speeds of 70 mph. I took the car to the dealership, but they could not find anything wrong because the dealer could only drive the car at the 55-mph speed limit. How can this problem be diagnosed? John
Dear John: A vibration indicates something is out of balance. The dealer does not have a way of simulating the car’s vibration at highway speeds in the shop. I would remove the tire and set it on a balance machine, without taking off any weights. The technician can also move the tire to the rear of the vehicle and let you road test it at the high speeds. Ask if they would let you take a technician on the highway during the drive. If you let up on the gas pedal at 70 mph and the vibration goes away, then the problem is in the driveline. A faulty inner axle C/V joint could be the cause. If the problem cannot be solved, then request that the dealer contact the local zone representative to meet with you. — Junior Damato, Motor Matters

Junior Damato is an ASE-certified Master Technician.

E-mail questions to info@motormatters.biz

Mail questions to: Auto Doctor, 3 Court Circle, Lakeville, MA 02347

Copyright, Motor Matters, 2010

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