Possible Causes
WARNING: This page is about a different car, the 2004 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
Passenger sensing system malfunction can be caused by seat weight sensor calibration not properly set, communication error between SAS control module and seat weight sensor control module, seat weight sensor control module internal malfunction, or left or right seat weight sensor malfunction.
- Inspect seat weight sensor control module connector
Turn ignition switch to LOCK position. Disconnect negative battery cable and wait at least one minute. Disconnect and inspect seat weight sensor control module connector. See SEAT WEIGHT SENSOR CONTROL MODULE under REMOVAL & INSTALLATION. If seat weight sensor control module connector is damaged, repair or replace air bag system wiring harness. Verify no Diagnostic Trouble Codes (DTCs) exist after repair. If seat weight sensor control module connector is not damaged, go to next step. - Inspect wiring harness
Access SAS control module and disconnect connectors. See SAS CONTROL MODULE under REMOVAL & INSTALLATION. Measure for continuity between SAS control module connector No. 1, terminal 1J and seat weight sensor control module connector terminal 3D. See Figure & Fig 1 . Measure for continuity between battery and seat weight sensor control module connector terminal 3A. Measure for continuity between ground and seat weight sensor control module connector terminal 3B. If continuity exist at all terminals, go to next step. If continuity does not exist at all terminals, repair or replace appropriate wiring harness. Verify no DTCs exist after repair. - Inspect passenger sensing system
Connect seat weight control module connector. Connect SAS control module connectors. Connect negative battery cable. Using scan tool, inspect PID/DATA monitor OCS-FLT. See PID/DATA MONITOR & RECORD under DIAGNOSTICS. If NO-Fail is displayed, go to next step. If NO-Fail is not displayed, perform appropriate operation below, according to PID displayed on scan tool.- If MOD-Fail or COMM-Fail is displayed, replace seat weight sensor control module. See SEAT WEIGHT SENSOR CONTROL MODULE under REMOVAL & INSTALLATION.
- If SNS-Fail-L is displayed, replace left seat weight sensor.
- If SNS-Fail-R is displayed, replace right seat weight sensor.
- If CAL-Fail is displayed, perform seat weight sensor calibration. See SEAT WEIGHT SENSOR CONTROL MODULE INSPECTION & CALIBRATION under REMOVAL & INSTALLATION.
- Inspect SAS control module
Retrieve Diagnostic Trouble Codes (DTCs). See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) under DIAGNOSTICS. If DTC B2290 is retrieved, replace SAS control module. If DTC B2290 is not retrieved, test is complete.