Toyota 4Runner airbags failing to deploy and alert sensor malfunction after collision on Toyota 4Runner

Some Toyota 4Runner owners report experiencing issues with airbag deployment failure during collisions, which may be attributed to several factors. These include a software error that was previously addressed by Toyota through a recall in January 2020 to modify the SRS harness. Additionally, damaged wiring, particularly under the seats, can contribute to this failure. In some instances, a broken or poor connection between the ECU and the airbags or sensors may prevent deployment. Owners should also be aware that the deployment threshold for airbags can vary depending on whether occupants are belted or unbelted. Furthermore, an illuminated airbag light after a collision may indicate a problem detected by the airbag control module, necessitating a diagnostic check of stored codes. It is crucial to note that the airbag control memory is volatile, and stored codes will be lost if the battery is disconnected, so it is advised to disconnect the main battery for about 10 minutes to ensure the backup power supply is depleted.