Q: The red brake warning light stays on even though I just put on new pads, front and back. A message on the dashboard says "check stabiltrac" and "check traction control," even though I just had shocks and struts replaced. A mechanic said the computers are not talking to each other. How can I fix this?
A: The red brake warning light comes on when the parking brake is engaged. There is a hydraulic leak, or the brake fluid is low. Typically, when the red brake light is on, the other systems become disabled, since they need fully operational brake hydraulics to work properly. I would start by checking the brake fluid level sensor in the brake master cylinder. If the sensor is faulty, the lights will be illuminated.
Q: My wife and I are the original owners of a 2004 Volvo XC90 with almost 140,000 miles.
Recently, the alarm went off at 2 a.m. when it was parked in the garage (it has always been garaged). I checked the car and garage and went back to bed. The next night it happened again, twice.
Online it says to replace the brain, but it's inside the right wheel well. A Volvo technician said to pull the fuse so it doesn't go off. I wasn't sure a replacement is available, and if it is, I thought it would be very expensive to fix. My wife loves this car and we have always taken very good care of it, but I'm afraid that it may cause other damage to the car's computer or electrical system.
Any advice would be appreciated.
A: You can read codes to see what caused the alarm to go off. The problems could be dirty battery connections or the battery nearing the end of its life, a courtesy light that comes on, a faulty motion sensor or even the alarm back-up battery.
The advice of removing the alarm fuse might be the easiest solution and will keep you from getting up at night.
Q: I love my Mercedes-Benz C 230. It has about 93,000 original miles and runs great.
In the last few months, there is what I would call a “creaking” noise coming from the driver’s side, especially when I make a right turn or enter a highway ramp turning right.
My auto shop has been trying to figure out what is making that sound. They have replaced the left and right outer tie rods; replaced the left and right upper control arms; replaced the left and right strut assemblies and strut mounts; and replaced the transmission mount. The noise still persists.
My mechanic assures me the car is safe to drive, but I’m concerned that the noise is an indication that something is going to happen. I even thought that perhaps the body and chassis are loose on the left side. I'd appreciate your thoughts.
A: There is a torque strut for the engine that, although it might look OK, may have a cracked bushing that can cause a creaking noise. Other times it is the body mounts that can be an issue.
I have seen some technicians solve these odd noises by loosening all the mounting bolts and retorquing everything back to the factory specifications.
Q: I need a new horn for a 2011 Suzuki SX4 anniversary edition sedan. The old horn stopped working and was removed, but the mechanic can’t find a replacement. Any help is appreciated, as the inspection comes due in March.
A: This is where the internet can be your friend. I found what appears to be a original manufacturer horn kit on RockAuto.com and a universal kit on CARiD.com. Both options will work and should get your car's horn ready for state inspection.
John Paul is the AAA Northeast Car Doctor. He has more than 40 years of experience in the automobile industry and is an ASE-Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email jpaul@aaanortheast.com and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.