B2002

Code

Generic B — Body

Occupant Classification System (OCS) Sensor Circuit Low Voltage

Brand: Generic

Type: B — Body

Views: UK: 10 EN: 12 RU: 15

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Page language: EN

Read DTCs and freeze-frame data with a compatible scan tool; note any related SRS codes
Visually inspect seat, connectors, harnesses, and underside of seat for corrosion, water or physical damage
Check SRS/OCS fuse and ignition-switched power circuits
Inspect and push/pull wiggle-test connectors while observing code or live data
Measure reference supply and ground at the OCS connector with key ON (follow SRS safety procedures)

Reference supply: typically 5 V (±0.5 V) or vehicle-specific supply — verify against manufacturer data
Signal voltage: varies with seat occupancy — commonly ~0.5 V (empty) up to ~4.5 V (occupied); low-voltage faults often
Short-to-ground: signal or supply near 0–0.5 V
Short-to-battery: signal or supply near vehicle battery voltage (~12 V) if shorted to Vb
Sensor mat resistance: vehicle-specific — often several hundred ohms to kilo-ohms; open/short indicates failure

Retrieve code(s) and freeze-frame with scan tool; note whether code is current or stored and any related SRS codes.
Follow vehicle manufacturer SRS safety procedures before probing connectors or removing the seat.
Perform visual inspection of seat upholstery, OCS connector, wiring harness routing, and underside of seat for damage, moisture, or rodent chewing.
With connector accessible, check for bent/corroded pins and secure mating; repair as needed.
With ignition ON (and following SRS safety guidance), measure reference supply and ground at the OCS sensor connector. Compare to manufacturer specs — if reference missing or low, trace back to fuse/power source.
Measure the OCS signal voltage with seat empty and with a known weight per manufacturer procedure (or carefully seat a person) to see if signal changes. If signal remains low, suspect sensor or wiring short to ground.
If low voltage suspected from wiring, disconnect sensor and measure continuity/resistance between sensor signal pin and module; check for short to chassis ground and short to battery.
If wiring checks OK and supply/ground are correct but signal is out of range, replace the OCS sensor mat/module.
After repair, clear DTCs, perform required OCS/occupant system re-learn/calibration per manufacturer, and verify system does not set code again.
If code persists, suspect SRS/OCS control module fault and consult manufacturer documentation or specialist equipment.