Plano, TX – March 1, 2018 – Toyota Motor Engineering and Manufacturing has recalled more than 48,000 vehicles potentially equipped defective air bag sensors, according to documentation submitted to the National Highway Transportation Safety Administration. The campaign affects multiple models, including:
- 2016 Toyota Prius hybrid sedans produced between June 9, 2015 and Dec. 25, 2015.
- 2015-2016 Lexus NX hybrid luxury crossovers produced between May 25, 2015 and Oct. 16, 2015.
- 2016 Lexus RX luxury sport utility vehicles produced between May 7, 2015 and Jan. 13, 2016.
Toyota is unsure what percentage of the vehicles actually contain the defective equipment.
Affected vehicles contain air bag assemblies featuring acceleration and pressure sensors with defective integrated circuit chips. These electronic components are coated in insulation prone to peeling. In the event that this does occur, an open circuit may materialize within the IC chip, causing the associated acceleration and pressure sensors to fail. Should this occur, front, side and curtain air bags may not deploy properly in the event of an accident. This poses a serious safety hazard to occupants. However, Toyota has yet to receive reports connecting the defective parts to any accidents or injuries.
Timeline of Events
In October 2015, Toyota received reports from the American and Asian markets outlining instances in which drivers observed their air bag warning lights illuminating, indicating that the safety features in their respective vehicles were not functioning properly, according to a chronology document submitted to the NHTSA. Toyota recovered parts from the vehicles referenced in the reports and conducted tests. These analyses showed that the pressure and acceleration sensors were not functioning due to an open circuit, a product of widespread IC chip insulation peeling. The vehicles involved in the reports were all produced in June and July 2015, and most originated from the Asian market.
Toyota continued to conduct tests throughout the fall of 2015 and winter, spring and summer of 2016. Eventually, these evaluations revealed that the Desno Corporation, the automaker’s air bag sensor supplier, had in November 2014 amended its gas flow control methodology for acceleration and pressure sensor insulation installation. This production change led to the release of high quantities of phosphorus gas. Denso eventually returned to its previous gas flow control strategy Dec. 13.
In June 2016, Toyota received another report centered on the nonworking pressure and acceleration sensors, this time from a dealer in the U.S. market. The automaker decided to consider regional environmental variability in its ongoing investigation in the defective parts, as it suspected humidity levels and temperature could play a role in the degradation of the IC chip insulation. Engineers involved in the inquiry also returned to the high phosphorus that resulted from Desno’s production adjustment. Toyota ultimately exposed the phosphorus-laden IC chips to high humidity and temperatures for extended periods of time in an effort to replicate the sensor dysfunction detailed in the original field report received in October 2015.
As these tests got off the ground, Toyota received additional reports outlining instances in which drivers had encountered air bag warning lights. The car company retrieved the parts installed in the vehicles mentioned in the report and found that their IC chips did not function. Engineers eventually found that another production malfunction at the Desno plant – this time the breakage of device meant to measure boron concentration levels within IC chip insulation – and laid the groundwork for failure. The devices shipped to Toyota featured insulation with overly high concentrations of boron and, as investigators eventually learned, facilitated the development of open circuits. Desno amended its production processes immediately to ensure such an error did not reoccur.
In April 2017, Toyota concluded the IC chip exposure tests and found that the phosphorus-filled insulation did indeed lead to the creation of open circuits, which could cause acceleration and pressure sensors to fail. The automaker also confirmed that high temperatures and humidity levels exacerbated the degradation of the insulation. The organization continued to explore this issue throughout the rest of 2017 and ultimately ended its investigation in January 2018.
On Jan. 25 Toyota quality assurance personnel reviewed the matter and decided to conduct a voluntary safety recall. Toyota informed dealers Jan. 31, at which point it had collected seven field technical reports and 110 warranty claims related to the defective acceleration and pressure sensors.
The automaker has directed dealers to replace the air bag sensors in affected vehicles free of charge, according to an NHTSA recall acknowledgement document. Toyota intends to notify owners via first-class mail between March 12 and April 1. Owners in need of more immediate assistance can connect with Toyota customer service personnel by calling (800) 331-4331 and using the internal recall identification codes JLA or J0F. They can also reach out the the NHTSA directly using its Vehicle Safety Hotline at (888) 327-4236.