Light Duty: Time For Tire Pressure Maintenance Systems

Since they come standard with all light-duty vehicles anyway, your fleet might as well start reaping the benefits.

The Tire Sentry system uses a series of electronic valve caps, replacing the existing caps, to warn the driver when any tire has lost as little as 10 percent of normal operating pressure. It can also tie in to the truck’s other electrical systems and send information directly to the home office.

Shore says advances in microchip technology have made electronic tire pressure monitoring more affordable for fleets.
“It can be quite an asset to a fleet to monitor tire pressure in a fashion of this nature,” Shore says. “It’s just they have never had an opportunity to monitor tires automatically at a reasonable cost to them, but that situation exists now, and that is within most operating budgets to have automatic tire pressure monitoring right from the cab.”


Light duty fleets can definitely benefit from TPMS just as much as heavy-duty fleets, Shore says.

“They are feeling the pinch in both their fuel economy situations and the continuing upper drive of tire cost, so they become more aware of what tire pressure monitoring can do,” he says. “As a result of that, we’ve come out with three new systems, dedicated primarily to the light truck market, and those can be easily installed.”

The newest wireless system plugs into a cigarette lighter and has all the electronic and display mechanisms built right into the plug, where it can monitor all the tires.

“It’s going to help them increase fuel efficiency and reduce tire maintenance costs, and one of the nice things about the system, it has low maintenance costs—all tire sensors run on battery power and ours runs on a replaceable battery,” he says. “The maintenance factor is one of the keys with just about any fleet operators, and our systems have very little maintenance required.”

Installation is very simple, Shore says, depending on the model.

“The easiest installation is with the new RC models that just plug into the cigarette lighters,” he says, “There are pedestal-mount models and most of our fleet models come with a two-inch round display that is easy to mount and those require providing 12 volts of power to it. The rest is just installing the sensors to the tires and installation is really minimal.”


Toyota uses a direct-type system that will turn on the tire pressure warning light to warn the driver of a low tire when the pressure of a tire becomes lower than the threshold, helping to prevent premature tire wear and fuel waste. The tire pressure warning valve and transmitter is integrated in the air valve of a wheel. Each tire pressure warning valve and transmitter consists of a lithium battery, sensor and transmitter.

“The tire pressure warning ECU receives the signals and determines whether the signals are coming from the vehicle’s own wheels,” says Bill Kwong of Toyota Motor Sales, U.S.A., Inc.

“If the measured values fall below the specified value, the tire pressure warning ECU transmits the signal to illuminate the tire pressure warning light in the combination meter.”

Kwong says tire pressure monitoring systems do not replace routine tire inflation pressure checks, however, noting that technicians should check tire pressure every two weeks, or at least once a month. He said maintenance on this system is minimal, though—once the technician initializes the system at new vehicle prep, no maintenance is required.

Ford introduced its first tire pressure monitoring system in 2002, on the ’03 Explorer, says Ford safety communications manager Wes Sherwood, to address tire pressure issues.

The current system warns a driver if one or more tires are significantly under-inflated using pressure sensors with radio transmitters on each tire. An in-vehicle receiver monitor will activate a warning light, or message in vehicles equipped with a message center. The system is used on Ford’s SUVs and trucks because of its ability to operate in four-wheel and all-wheel drive and in off-road environments.

Ford’s systems include a diagnostic function that flashes a warning light for 60 to 90 seconds when it detects a malfunction. It also uses wheel well-mounted pressure sensors to reduce susceptibility to damage when changing a tire, compared to valve stem-mounted sensors.


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