B10B2

Code

Generic B — Body

Occupant Classification Sensor Circuit Fault

Brand: Generic

Type: B — Body

Views: UK: 23 EN: 27 RU: 26

AI status

Completed

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Page language: EN

Causes

Open or short in OCS wiring or harness (including pins or connector corrosion)
Damaged or worn occupant classification mat (broken traces or moisture intrusion)
Poor or lost ground or reference voltage to the sensor circuit
Connector contamination, bent pins, or poor contact at seat harness or SRS module
Intermittent fault from seat movement, seat heaters, or aftermarket seat covers
Faulty occupant classification sensor module or SRS control module software/hardware

Symptoms

SRS/Airbag warning lamp illuminated
Passenger airbag ON/OFF light may be incorrect or disabled
Possible inability for system to enable/disable passenger airbag automatically
Relevant occupant classification-related DTC stored in SRS module
System may enter a restricted state (passenger airbag disabled)

What to check

Read stored DTCs and freeze-frame data with an appropriate SRS-capable scan tool
Visually inspect occupant mat, seat wiring, connectors and routing for damage, corrosion, compression, or water
Check for aftermarket seat covers, repairs or debris that could interfere with the mat
Verify vehicle battery state and SRS fuses/relays are intact
Perform a wiggle test of the seat harness while monitoring live data for intermittent changes

Signal parameters

Reference voltage typically 5 V (sensor or module supplied) — verify per vehicle spec
Signal circuit voltages normally vary between 0–5 V depending on sensor design and load (or present as variable resistance)
Expected resistance change across mat elements when occupant weight applied (compare to OEM specification)
Continuity to ground should be near 0 Ω for ground circuits; no short to battery voltage on signal lines

Diagnostic algorithm

Follow SRS safety procedures first: disable battery and wait manufacturer-specified time before accessing seat wiring/airbag components
Connect SRS-capable scan tool, record B10B2 and any related codes, and view live OCS data and freeze frame
Visually inspect seat cushion, mat, harness routing, connectors, and pin condition. Remove seat trim as needed.
Restore battery (if removed for inspection) and monitor live data while performing gentle wiggle tests on harness and connectors to reproduce fault
With ignition on (and following safe practices), verify reference voltage and ground at the OCS connector. Check for short to battery or ground on signal wires.
Measure resistance or output of the occupant mat sensor elements per OEM procedure. Compare to specification or known-good seat; some mats can be bench-tested.
If wiring and connectors pass, swap or simulate mat input (use OEM-specified test resistor if available) to determine if the mat or SRS module is at fault.
Repair wiring/connector issues: clean, repair pins, replace damaged harness, or replace occupant classification mat as required. Clear codes and test-drive/monitor to confirm repair.
If fault persists after sensor/mat replacement, consider SRS control module fault and follow manufacturer procedures for module diagnosis/flash/replace

Likely causes

Open/short in seat wiring harness at seat frame or under-seat routing
Corroded/contaminated connector at seat occupancy mat or module
Damaged occupant classification mat (tear, water ingress, internal trace break)
Faulty ground or blown SRS fuse

Fault status

⚠️ Status

Occupant Classification Sensor circuit fault — electrical fault detected in seat occupancy sensor circuit (open/short/intermittent). Airbag occupancy function may be disabled.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours