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Why is my car getting TPMS warnings when the pressure is fine?

John Paul, AAA Northeast's Car Doctor, answers a question from a reader whose older vehicle is showing the TPMS warning.

Car Doctor -- The Honda logo on the outside of the company's final assembly factory in Swindon, U.K., on March 9, 2021.
The Car Doctor answers a reader's question about a tire pressure monitoring system (TPMS) light. Bloomberg photo by Chris Ratcliffe

Q. I have a 13-year-old Honda with 120,000 miles. The TPMS keeps coming on. This is not the low-pressure light I see when the outside temperature is very cold, but the actual letters TPMS. The car is garaged throughout the winter, only coming out for family emergencies from November to April. Because of the sensor being on, I’m always checking the tire pressure, which remains at a constant approximately 32 PSI. Why is this sensor on all the time?

A. There are two types of TPMS systems – direct and indirect. The indirect system measures wheel/tire rotation using the anti-lock brake system. A low tire will roll at a different speed than a fully inflated tire. The other system is a direct system which uses battery-powered radio transmitters at each wheel and will give an actual pressure reading for each tire (most cars). When the transmitter stops functioning, the TPMS system light will come on to tell you there is an issue with the system. The typical life of these battery-powered systems is seven to ten years. Until you decide to replace the sensors, continue what you are doing and check the tire pressure once per month. 


Q. My 2005 Honda Accord with 150,000 miles recently had a few quick power drops while cruising at 60 miles per hour as well as frequent stalling while idling. I suspect the cause was bad gasoline. I flushed the system with fuel system cleaner and added high-test gas at various times. Everything ran fine until four weeks later when the car again had two quick power drops while cruising at 55 miles per hour and one stall while idling. The check engine light came on but went off after 10 minutes. The car did not save the codes. My mechanic says the fuel filter and pump may need to be replaced, which would be expensive, and he is not sure if that is the problem. Any thoughts? 

A. More testing will be needed to make an accurate diagnosis, but I suspect your mechanic may be correct. The best testing method would be to monitor the fuel system while driving and record fuel pressure when the engine acts up. 

Q. What do you think of the new Ford Maverick truck, and how does it compare to the Hyundai Santa Cruz? 

A. If I were to buy a Maverick truck I would buy the front-wheel-drive hybrid. To me it is the best value of just about any vehicle today. As you move up to the all-wheel-drive version with the larger engine, the Hyundai starts to look like the better vehicle. Both are particularly good, and, in my opinion, are part of the sorely missed category of small, useful trucks that are not outrageously expensive. 


Q. I have my dad’s 1985 Ford Crown Victoria which has not run in at least 10 years. It’s been sitting in a carport. I want to see about getting it back on the road and thought it would be a good project with my kids. I was on YouTube and was watching Vice Grip Garage. The host gets old cars running all the time. Where do I start? 

A. You will have a fair amount of work ahead of you. The fuel in the tank has certainly gone bad, the fuel pump has probably frozen up and won’t pump fuel, and of course it will need a new battery. The cooling system, belts, hoses, thermostat, and perhaps even the radiator may need replacement. Then, once the engine is running (you may need to replace the spark plugs) you need to evaluate the brake system. More than likely the brakes are rusted and even the  brake lines could be leaking or in need of replacement. The first place to start is to see if the engine will even turn over. Sitting for 10-plus years, the engine could be locked up. And of course, you will not know the condition of the transmission until you get the engine running. If you have the time and budget, and consider this a labor of love, then give it a go. If this were just a car you were going to fix up and drive, I would probably look for something else. Also, keep in mind that Derek, the host of VGG, is a character, but also is a skilled technician with years of experience. 


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


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