It’s no secret that drivers are keeping their cars longer these days. Thanks to improvements in automobile materials, design and construction, motorists can comfortably push their odometers past the 200,000 mile mark in many instances.

But even though your car as a whole may age well, certain components may not. And they’re not always easy or cheap to replace. Take Tire Pressure Management Systems (TPMS), for example. Designed to alert drivers to an under-inflated tire, they’re federally mandated on all new vehicles built after September 1, 2007. (This mandate came in response to a rash of highly publicized accidents attributed to mass failure of certain Firestone tires.)

When the battery powering the individual TPMS wheel sensor dies (usually after 5-7 years), the entire sensor module has to be replaced, as one NMA member learned the hard way. The cost to replace all four sensors in his 2004 VW Toureg totaled $800 (parts and labor). But his dealer warned that the system may not be able to read the new sensors, necessitating a replacement interface module for an additional $600.

That’s a potential out-of-pocket expense of $1,400 for a “nice to have” feature, as our member put it. He decided the safety and convenience benefits weren’t worth the cost. (Granted, the costs in this case may be on the high end. Other members have reported that replacement sensors for their vehicles cost about half as much.)

Our member then wondered about the consequences of having a non-functioning TPMS. He was concerned that he may not pass his state-mandated emissions inspection since he reasoned that properly inflated tires would increase his fuel mileage. His concerns are likely unfounded since the TPMS mandate pertains to safety standards, not emissions. Moreover, most states do not inspect the TPMS as part of routine vehicle inspections.

But before you decide save your hard-earned cash and leave those dead TPMS sensors in place, consider this: at least four states do mandate proper TPMS function as part of the annual vehicle inspection—Hawaii, Rhode Island, Vermont and West Virginia. (Click here for more state-specific information.) Others may as well. If you live in a state that requires vehicle inspection, contact your DMV to see what’s on the inspection list for your area.

This is not the first time the TPMS has thrown a member a curve. In a previous E-Newsletter (#75: Tire Pressure Monitoring Systems) a NMA member described the complicated steps involved simply to reset the TPMS warning light once the system had been activated.

Click here for more information on TPMS.