NHTSA Preliminary Evaluation PE23009

On June 8, 2023, Office of Defects Investigation (ODI) opened Preliminary Evaluation PE23009 to investigate reports of air pressure loss from tires equipped with Danko Manufacturing/RViBrake’s (RViBrake) Tire Patrol device, an aftermarket tire pressure monitoring system. ODI’s initial inquiry determined that RViBrake was aware of 408 sensors being returned under warranty for leaking pressure, including approximately 40 that were reported to have broken in half, leaving the tires’ valve stem core pressed open and leaking air. ODI sent an Information Request (IR) letter to RViBrake on June 8, 2023. By analyzing the IR Response data, ODI learned that the bulk of the sensors returned under warranty were for dead sensors, or minor but consistent air leaks. The manufacturer believes that many of the warranty claims are user-induced, such as damage from curb strikes or from car washes.  However, 41 warranty claims  were for lost upper sensor halves, a condition that can cause the tire to deflate, without notification to the operator. This condition is particularly concerning when it occurs to one of the vehicle’s steer axle tires.  No crashes or injuries are known to be directly attributable to any of these sensors. RViBrake explained that in the event of a sensor half detachment, the operator would not immediately be warned. The system refreshes the tire pressure information every three minutes, but it is not uncommon for a packet of information to not be received due to interference, especially with the rear wheels, which may be further away from the receiver.  If the system does not receive fresh information from the sensor three times in a row, the icon for that sensor becomes greyed out on the display screen.  Furthermore, if the system does not receive information from the sensor five times in a row, an audible alert sounds to warn the operator.  As part of the IR response, RViBrake supplied a video replicating the worst case scenario.In the video, a broken and separ