WASHINGTON—The National Highway Traffic Safety Administration (NHTSA) should require auto makers to educate consumers about the maintenance requirements of tire pressure monitoring systems (TPMS), according to two industry trade groups, the Tire Industry Association (TIA) and the Automotive Oil Change Association (AOCA).

Specifically, TIA said, written instructions on TPMS in vehicle owners' manuals are inadequate to explain the technology to motorists, and motorists are too often confused about TPMS warning lights that remain temporarily illuminated after service, causing them to accuse tire retailers of damaging the systems.

The associations submitted their comments to NHTSA in response to a November 2012 request for feedback on the economic impact of its regulations on small entities. The request for comments was required under Section 610 of the Regulatory Flexibility Act.

The federal TPMS rule requires auto makers to include an image of the Low Tire Pressure Telltale Symbol in owners' manuals, along with a statement about the function of TPMS and the necessity of proper tire inflation.

However, the agency doesn't require auto makers to explain that telltale symbols serve two purposes, said Roy Littlefield, TIA executive vice president, in his Jan. 22 comments. The symbols indicate not only low pressure in a tire, but also a malfunction in the system, he said.

“Since the owners' manual is not required to explain the difference, the burden often falls on the tire retailers, who must explain why a telltale (symbol) that stays illuminated after the bulb check represents a low tire and a telltale (symbol) that blinks for 60-90 seconds and then stays illuminated represents a malfunctioning TPMS,” Mr. Littlefield said.

“Small businesses waste thousands of dollars each year in lost productivity explaining these federally mandated safety features,” he said.

Auto makers also aren't required to inform motorists of the lifetime cost of maintaining a TPMS; of the different requirements for resetting a TPMS after servicing, some of which demand additional time and tools; or of the amount of time needed for the telltale light to be extinguished after a problem is corrected, according to Mr. Littlefield. The last is particularly harmful to tire retailers, he said.

“When vehicles are returned to the consumer with the telltale illuminated, many of them assume the retailer damaged the system, so they take it to the new car dealer,” he said.

Some car dealers have told vehicle owners falsely that retailers damaged the sensors, and installed new sensors that retailers were expected to pay for, Mr. Littlefield said.

“TPMS has already created a significant financial burden on tire service providers,” he said. “The inadequate written instructions required by (the NHTSA standard) only compound the problem and put these small businesses at a bigger financial disadvantage.”

Echoing TIA's comments, the AOCA said consumers are told too little about TPMS, how it operates and what it costs to be maintained.

“Consumers routinely arrive at small business automotive service facilities with malfunctioning TPMS equipment, like corroded sensor valves, and are caught completely off guard by both the problem and the cost involved,” said AOCA President Patricia Wirth.

The average cost of a TPMS sensor valve replacement is $103, and more often than not the garage owner must eat the cost, rather than lose the customer forever, Ms. Wirth said.