tire pressure monitoring system

 

The tyre pressure monitoring system (TPMS) in your vehicle is designed to alert you if one or more of your tyres is considerably under-inflated, potentially resulting in risky driving conditions. The TPMS low tyre pressure indication is a yellow sign in the form of a tyre cross-section (which resembles a horseshoe) with an exclamation point that glows on the dashboard instrument panel. Your vehicle's indicator light has a history. It's a history that dates all the way back to years of ambiguity about correct tyre pressure and several severe auto accidents that may have been prevented if drivers had recognised their air pressure was low. Even today, it is expected that a significant number of cars operate with underinflated tyres on a daily basis. However, appropriate tyre maintenance with a TPMS may and can help avoid a significant number of major incidents.

Prior to the advent of this indication light, determining if your tyre pressure had dropped to hazardous levels required exiting the vehicle, stooping down, and using a tyre measure. With rare exceptions, this was the sole pressure-testing equipment available to regular customers.

Tire Pressure monitoring system 

The US government then enacted the Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act in response to an increase in accidents caused by underinflated tyres. As a result of this law, the majority of automobiles sold in the United States since 2007 have had some kind of tyre pressure monitoring device.

Not all TPMSs operate in the same manner. The low tyre pressure indicator's lighting signifies the conclusion of either an indirect or direct TPMS operation. TPMS INDIRECT: INDIRECT TPMS - WHAT IS IT & HOW DOES IT WORK?

Indirect TPMSs often rely on the anti-lock braking system's wheel speed sensors. These sensors monitor the revolutions per minute made by each wheel and allow on-board computer systems to compare them to one another and to other vehicle operating data such as speed.

The computer can determine the relative size of the tyres on your car based on the rate of rotation of each wheel. When a wheel begins to spin quicker than normal, the computer determines that the tyre is underinflated and notifies the driver.

As a result, an indirect tyre pressure monitoring system is not capable of measuring tyre pressure directly. It is not an electrical device that does the same kind of measurement as a tyre gauge. Rather than that, an indirect tyre pressure monitor merely analyses the speed at which your tyres rotate and transmits signals to the computer, which activates the indication light when anything seems to be wrong with the rotation.

ADVANTAGES OF INDIRECT TPMSIndirect TPMS are less costly than direct TPMS.

— Over time, requires less programming/maintenance than a direct TPMS

— Less maintenance required on an overall basis than its direct equivalent

INDIRECT TPMS DISABILITIES — May become incorrect if a larger or smaller tyre is purchased.

— Can be unreliable if tyres are worn unevenly

— Must be reset once each tyre is properly inflated

— Must be re-calibrated after normal tyre rotation

WHAT IS DIRECT TPMS AND HOW DOES IT WORK?

Direct TPMS monitors particular pressure levels inside each tyre — not simply wheel rotation data from the anti-lock braking system.

Sensors included into a direct TPMS may potentially offer temperature measurements on the tyres. The direct tyre pressure monitoring system transmits all of this data to a centralised control module, where it is evaluated and processed before being communicated directly to your dashboard, where an indicator light lights if tyre pressure is lower than it should be. Typically, a direct tyre pressure monitor transmits all of this information wirelessly. Each sensor is identified by a unique serial number. This is how the system identifies itself not just from other cars' systems, but also from individual tyre pressure measurements.

Because many manufacturers employ proprietary technology for these highly specialised systems, changing a TPMS in a manner that is consistent with and compatible with your vehicle requires the expertise and understanding of an experienced, qualified technician.