Q: I’m hoping you can help us on this one. My cousin inherited her father’s 1991 Acura Legend when he passed away. The car was is in great condition with everything working well, except the radio. It just displays “CODE.” I’m guessing when a new battery was installed the code somehow got erased. We can’t find any reference to a specific radio code sequence anywhere in her father’s service records. The dealer wants an exorbitant sum of cash and time to turn the radio back on for her. Sounds like highway robbery to me. I’ve always had cars with radios that just worked. Can you help us find the code and tell us how to reset this radio?

— Bob M.

A: This isn’t too difficult, and there are several ways to proceed. To obtain the radio code, you’ll need to acquire the serial number from the unit. On Acuras built since model year 2001, the serial number can be brought up on the display by pressing and holding radio preset buttons 1 and 6 — with the key on, then turn on the radio.

Next, combine the two groups of numbers as they scroll by. On earlier radios such as yours, the serial number is found on a sticker on the rear of the radio, requiring removal to view it. There’s a chance you may also find the serial number on a sticker affixed to the side or interior of the glove box.

Obtaining the radio code is a simple matter via the dealer, Acura’s website or an online provider such as radiocode.com once the serial number has been located. Acura’s helpful web service (https://radio-navicode.acura.com) is easy to navigate, although you’ll need the original owner’s ZIP code and phone number recorded at the time of purchase. I’m thinking a big smile and a box of donuts, during a slow driveway period (late morning or midafternoon) might work at the dealer, and the service consultant isn’t likely to be as fussy about original owner information as long as the car is present. Radio-Code.com will also provide a code, using your serial number, for $25.

Q: I’ve notice when I brake hard the front of my car shudders. It stops fine, but the shuddering is unnerving. What can cause this?

— Amanda Collins

A: Your car appears to be suffering from warped front brake rotors. These dinner-plate-sized disks are pressed upon by the brake pads, converting kinetic energy into heat. If there’s too much heat generated, if wheel lug nuts are improperly tightened, or if unusual wear occurs, rotors can become distorted. You’ll want to have them checked for run-out, parallelism and thickness, along with a general brake inspection. A binding caliper, faulty brake hose or incorrect brake pads could be a contributing culprit.

As brake rotors wear, they become thinner, and more prone to warping. Minor surface flaws can be corrected by machining the rotors, but only to a point, as a minimum thickness must be maintained. There’s a good chance you may need new rotors. Shop quality, not price, and be sure new brake pads of the proper composition and quality are mated with them.