How To

An odometer oddity between two different pickup trucks

John Paul, AAA Northeast's Car Doctor, answers a question from a reader seeing different mileage for the exact same trip between their old and new trucks.

The Car Doctor answers a question from a reader seeing different mileage for the exact same trip between their old and new trucks. Toyota

By John Paul

July 29, 2025

4 minutes to read

Q. In March I turned in my leased 2022 Toyota Tacoma SR5 and leased a 2025 Tacoma SR5. In my 2022 Tacoma, my trip to work was 13.9 miles every day consistently, according to the display. In the 2025, it’s 14.2 miles consistently. Same size tires, same model truck. Any ideas why this would happen? It is not much, but mileage adds up, especially in a leased vehicle.

A. Odometers by regulation can vary, and as I remember, by four to 10 percent. This means that if the sensor or gear on an older vehicle can have an incorrect reading, both the speed and distance traveled will be inaccurate. Even the variance in tire wear can cause a difference in reading. At this point it would be best to determine which is accurate — a GPS is generally considered the most accurate method. Once you have the correct answer, then talk with the dealer to see what they say. Twenty-five years ago, there was a class action lawsuit filed against Honda due to odometers that were racking up miles too fast. Honda asserted that the odometers on some six million Hondas affected by the suit were accurate to within 3.75 percent on the high side. Honda agreed to a class action settlement and agreed to lengthen the warranty mileage of affected vehicles by 5 percent and pay lease-mileage penalties incurred by owners of Honda or Acura between 2001 and 2006.

Q. I have a 2012 Cadillac CTS, and the air conditioner expansion valve needs to be replaced. Can you replace it without taking the whole car dashboard apart? Any advice would be helpful.

A. I have never tried to replace one, but according to the manufacturer’s service data, no. If fact, the flat-rate time to replace the expansion valve/block is seven hours, not including the recharging of the system when the work is complete. Is it possible to do the work without disassembling the dash? It is possible, at least according to some YouTube videos. This guy claims he did it. Watch the video and decide for yourself.

Q. My check engine light came on several months ago on my 2007 GMC truck and the scan claimed issues with the fuel tank pressure sensor. In December there was major body work for rust removal. That included removing the fuel tank. My question: when the mechanics removed and installed the fuel tank, how likely might it be that the return trip was not up to par, so the check engine light came on? The problem is I cannot prove any degree of negligence, but I do not want to have to perform costly work if it is not necessary.

A. It is possible that the wiring was damaged or wiring and connections were just rusty and crusty and fell apart at the tank when the rust repair was performed. The wiring sits above the frame rails and if they did rust repairs, it is certainly possible. The sensor is a part that sits in the area of the fuel tank sender and fuel pump. To inspect the wiring and sensor, the fuel tank typically needs to come out or at least be lowered. I would first start by talking with the technicians that performed the rust repair and then go from there.

Q. When getting your car repaired is it better to tell the mechanic everything you know about the car or just let them diagnose it? A friend of mine keeps telling me the more you say, the more it will cost, what do you think?

A. I have to disagree with your friend. If I were fixing a car, I would want to know the history of what work was performed, other possible diagnostics, and what DIY repairs were performed.

Q. I own a 2016 Nissan Rogue with around 30,000 miles. I noticed that the passenger air bag indicator was always OFF when an adult was sitting in the passenger seat. I took it to the dealer, and they quoted me a price of $1,600 to replace the OCS control unit. I decided to get a couple of other estimates but both repair shops told me I had to go back to the dealer to fix the problem. Why is the dealer the only place that can fix this? Why aren’t the repair shops allowed to do so? Also, I contacted NHTSA to see if there were any recalls on my car but never heard back from them.

A. The Occupant Classification System (OCS) determines if there is an adult or child in the passenger seat and can determine if the airbag should be deployed. This system looks at weight and proximity of the seat to the dash. Any repair shop who is willing can repair this vehicle. They may need to buy service data from Nissan to perform any programming. For many independent shops, unless they do this work regularly, the return on investment is just not worth it. There was a voluntary recall on this system. Also, regarding recalls, download the NHTSA app, and put in your car’s vehicle identification number. If there are any recalls they will be listed on the app.

John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your Car Doctor question to [email protected]. Listen to the Car Doctor podcast at johnfpaul.podbean.com.