B1A67

Code

Generic B — Body

Occupant Classification System — Passenger Seat Sensor Fault

Brand: Generic

Type: B — Body

Views: UK: 10 EN: 16 RU: 13

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Faulty passenger seat occupancy sensor module or mat
Open, shorted, or corroded wiring/connectors between sensor and control module
Poor connector seating or bent pins at seat module, airbag/BCM, or junctions
Water intrusion or physical damage to seat cushion/sensor mat
Faulty occupant classification control module or related airbag/BCM software/firmware issue
Intermittent fault caused by seat position/frame interference or aftermarket seat coverings

Passenger airbag may be disabled or status light illuminated
Airbag warning lamp or OCS warning on instrument cluster
Diagnostic trouble code stored in airbag/BCM memory
Possible change in passenger detection (seat reports empty or occupant incorrectly)
Intermittent or permanent disablement of passenger airbag

Read Codes and freeze frame with OEM scan tool; check for related airbag/BCM codes
Visually inspect passenger seat and under-seat area for damage, loose connectors, debris, or water
Check connector pins for corrosion, bent pins, or pushed-out terminals
Verify no aftermarket seat covers, heavy mats, or child seats that could affect sensor
Check technical service bulletins (TSBs) for known issues or calibration procedures

Occupant sensor reference voltage: typically 5.0 V supply (verify with factory data)
Sensor output: resistance or capacitance values vary by design — expected range per OEM spec
CAN/CAN-FD or LIN messages: OCS status message frequency typically 1–10 Hz (check OEM data)
Fault criteria: out-of-range, open/short to ground or battery, implausible signal, communication timeout

Retrieve and record all codes, freeze frame and current data from airbag/BCM/OCS using an OEM-capable scan tool.
Inspect passenger seat area: remove seat trim/access panels and visually inspect the sensor mat, harness, connectors and ground points for damage, corrosion, or loose terminals.
With connector disconnected, check continuity and resistance of sensor leads to the module per OEM specification; check for shorts to ground or battery.
Reconnect and backprobe the sensor connector while monitoring reference voltage and sensor signal with a multimeter/oscilloscope. Compare to OEM signal parameters.
Check bus communication (CAN/LIN) for OCS messages and verify module addresses and message rates using a diagnostic tool; look for timeouts or invalid data.
If wiring and connectors are good but readings are out-of-range, replace or reseat the passenger seat sensor/mat assembly per OEM procedure.
After repair, clear codes and perform required OCS calibration or learning procedure as specified by manufacturer; verify code does not return and passenger airbag status is correct.
If fault persists after sensor replacement, consider replacing or reprogramming OCS/airbag/BCM module and perform module coding/learn steps as required.