B002C

Code

Generic B — Body

Front passenger occupant classification sensor circuit fault

Brand: Generic

Type: B — Body

Views: UK: 11 EN: 18 RU: 14

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Damaged or pinched wiring harness under the passenger seat
Loose, corroded or disconnected seat/sensor connector
Faulty occupant classification sensor (seat mat or module)
Water/moisture intrusion into seat module or mat sensor
Poor or lost ground/reference supply to the sensor
Faulty occupant classification control module or ECU

Symptoms

SRS/airbag warning lamp illuminated
Passenger airbag status may show ‘OFF’ incorrectly or be unavailable
Passenger presence/weight indicator incorrect or not displayed
Possible inability for passenger airbag to deploy (system may disable as a precaution)
Intermittent faults that change with seat position or occupant movement

What to check

Scan for DTCs and note freeze frame/live data for passenger OCC sensor
Check for additional SRS or communication codes (related airbag or module errors)
Visually inspect passenger seat and underside for water, damage, loose connectors, pinched wires and unsecured seat fasteners
Perform a wiggle test of the seat harness while monitoring live data or codes to reproduce fault
Check connectors for corrosion, bent pins, or poor mating; disconnect/reconnect to reseat contacts
Verify grounds and power supply to seat occupancy module and sensors

Signal parameters

Sensor uses a variable occupancy signal referenced to vehicle supply (typical sensor signal range 0–5 V; confirm OEM spec)
Open circuit appears as no/erratic signal or infinite resistance; short to ground/battery will pull signal low/high
Resistance/impedance of seat mat/sensor varies with load — manufacturer lists specific values (consult service manual)
Diagnostic data may include a binary occupied/unoccupied status and a raw sensor value or CAN message from occupant classification module

Diagnostic algorithm

Read/record all stored codes and freeze frame data with a capable scan tool; clear codes after recording and attempt to re‑create.
Inspect passenger seat area (surface, underside) for spills, corrosion, damage, or signs of previous repairs. Check seat rails where harness can be pinched.
Visually inspect and disconnect the occupant sensor connector(s). Check pins for corrosion, bending, or pushed‑out terminals. Repair or replace damaged connectors.
With battery voltage present, backprobe reference, signal and ground circuits at the sensor connector. Compare to expected values (reference voltage present, good ground, signal responsive to weight).
Perform continuity/insulation resistance checks on wiring between sensor and occupant classification module; look for opens/shorts to ground or battery.
Monitor live sensor data while applying known loads (adult, child seat simulator if available) and while moving the seat to reproduce intermittent faults. Use wiggle tests on harness.
If wiring and connectors are good but sensor signals are out of range, replace the occupant classification sensor (seat mat) or sensor module per manufacturer procedure.
After repair, clear codes, perform calibration or seat sensor initialization if required, and verify proper operation with scan tool and functional tests.
If fault persists, consider replacing or reprogramming the occupant classification control module and re‑check CAN/communication circuits.

Likely causes

Wiring abrasion/pinch from seat movement causing intermittent open/short
Connector contacts contaminated with corrosion or moisture
Damaged sensor mat from a spill or physical impact
Connector not reseated after seat removal or service

Fault status

⚠️ Status

Front passenger occupant classification sensor circuit fault detected. SRS warning lamp illuminated; passenger airbag status may be inhibited until fault is corrected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours