Toyota Motor Engineering & Manufacturing (Toyota) will be contacting the owners of certain 2022 Lexus NX250, 2022 Lexus NX350, and 2022 Toyota Tundra vehicles, because these vehicles may fail to comply with the requirements of the Federal Motor Vehicle Safety Standards for light vehicle braking systems.
Toyota and their brake system supplier became aware of the problem and began a quality investigation in late January 2022, after receiving a report of a customer not being able to disengage the Electronic Parking Brake (EPB). The investigation led to reports of other drivers not being able to engage or disengage their EPB. Although Toyota was unable to duplicate the condition, they did find an instantaneous voltage gap that could occur within the ECU’s ASIC during the Motor Test Pulse (MTP) self-diagnostic check. A series of tests confirmed that the characteristics of resistors within the ECU’s noise filter could cause the voltage gap. During the end of July through mid-August, Toyota conducted vehicle tests to confirm the Motor Test Pulse failure condition and identified that, under certain conditions, this could prevent the EPB from engaging. Based on the results of the investigation indicating that this phenomenon could occur prior to the first sale, on August 26, 2022, Toyota decided that the subject vehicles may not meet the requirement of FMVSS No. 135 paragraph S7.12.3.
According to the defect report, the skid control ECU within the brake actuator assembly may falsely detect an over-current condition of the EPB Actuator and enter a fail-safe mode which prevents the EPB from being engaged. If the EPB cannot be engaged, the EPB MIL and MID warnings are ignored, and the vehicle is parked on a grade without being placed into “Park,” the vehicle could roll away, increasing the risk of a crash.
Owners who receive notices will be asked to return to their Toyota or Lexus dealer to have the Skid Control ECU reprogrammed. Toyota's numbers for this recall is 22TA11 and 22LA04 and the NHTSA campaign number is 22V-661.