TPMS System Module

The SJB contains the TPMS functionality. The 2 systems have separate diagnosis and testing but they are serviced as one module. See TIRE PRESSURE MONITORING SYSTEM (TPMS) - DIAGNOSIS , for TPMS fault diagnosis and repair.

The SJB compares the information of each tire pressure sensor transmission against a pressure limit, the SJB determines that the tire pressure has fallen below the low limit (the pressure listed on the vehicle certification label minus 25%), the SJB communicates this to the instrument cluster on the vehicle communication bus.