B102D

Code

Generic B — Body

Occupant Detection Sensor Circuit Fault (Front Passenger)

Brand: Generic

Type: B — Body

Views: UK: 4 EN: 12 RU: 5

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Damaged or disconnected seat occupant sensor mat or wiring harness
Corroded, loose, or contaminated connector under the front passenger seat
Water/moisture intrusion into the seat or connector area
Short to power or ground in the sensor circuit
Faulty occupant detection sensor module or occupant classification module (OCM)
Improperly installed aftermarket seat covers or repairs that alter sensor behavior

Read and record all stored SRS/airbag codes and freeze frame data with a capable scan tool
Observe live data/occupancy status for the passenger seat with and without a passenger present
Visually inspect the passenger seat, seat bottom/rail area and wiring harness for damage, pinch points, or water entry
Unplug and inspect seat harness connectors for corrosion, bent pins, or contamination; reseat connectors
With ignition ON, verify reference supply voltage to the sensor harness (see vehicle manual) and check for signal presence/changes with load
Perform a wiggle test of the wiring and connectors while watching live data or the DTC status for changes

Reference supply typically provided by the module (commonly ≈5 VDC on many systems) — consult vehicle-specific manual for exact value
Signal range depends on sensor type: may be an analog voltage, resistance/capacitance change, or digital data — typical voltage signals use a 0–5 V range
Expected behavior: stable reference voltage with ignition ON; signal should change when a passenger sits or leaves the seat
If the sensor is resistive, resistance will change with load — exact ohms depend on design; consult vehicle datasheet for target values

Safety first: follow SRS safety procedures. Disable the battery and wait the manufacturer-specified time before working on SRS components.
Use a scan tool to read and record DTCs and live occupant detection data. Note freeze frame and any related SRS codes.
Clear codes and see if B102D returns. If intermittent, reproduce by sitting/wiggling seat harness.
Visually inspect seat cushion, cover, and underside for damage, moisture, or foreign objects. Remove any aftermarket seat covers.
Inspect connectors under the passenger seat and at the occupant classification/airbag module. Unplug, inspect terminals, clean if necessary, and reconnect securely.
With manufacturer procedures, measure reference supply and signal at the sensor connector with ignition ON. Verify signal changes when a test weight or person sits/stands on the seat.
Perform continuity and short-to-ground/power checks on the suspect wiring from the sensor mat to the module with harness disconnected. Repair any open or shorted wiring.
If wiring and connectors are good, measure sensor mat resistance/capacitance per the service manual. Replace the sensor mat if out of specification.
If sensor mat and wiring pass, evaluate/reprogram or replace the occupant classification module or airbag control module as directed by manufacturer diagnostics.
After repairs, clear codes and perform required calibrations or occupant classification relearn procedures. Verify correct operation and that code does not return.

Broken or chafed wiring under the seat where harness moves
Connector pin corrosion or bent pins at seat harness or module connector
Failure of the sensor mat (open/short or out-of-spec resistance/capacitance)
Module fault or need for recalibration after seat removal or repair
Moisture contamination of the mat or connector causing intermittent circuit fault