B3692

Code

Generic B — Body

Occupant Classification Sensor 2 Circuit Fault

Brand: Generic

Type: B — Body

Views: UK: 0 EN: 0 RU: 0

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Damaged or disconnected sensor connector under the seat
Broken, chafed or shorted wiring harness between sensor and SRS/BCM
Corroded terminals or water ingress in seat cushion/sensor area
Failed occupant classification sensor (mat/capacitive/resistive element)
Faulty SRS/airbag control module or internal driver circuit
Aftermarket seat covers/heated seats or improper repairs affecting the sensor

Symptoms

Airbag warning lamp illuminated and DTC B3692 stored
Possible passenger airbag disablement or “PASSENGER AIRBAG OFF” status incorrectly displayed
Occupant classification system may not detect occupant or may show inconsistent passenger status
Related safety system messages or reduced restraint functionality
Intermittent faults that reappear after moving the seat or tapping under-seat components

What to check

Use a diagnostic scan tool to read all stored codes and freeze-frame data; record occurrence and any related B/U or U-codes
Visually inspect under-seat area: connectors, clips, harness routing, seat frame contact points and signs of corrosion or foreign objects
Check for aftermarket equipment (seat covers, seat heaters) that could interfere with the sensor and remove if present
Check SRS-related fuses and relays per vehicle manual
Wiggle the seat and connectors while monitoring live data or re-scan to see if fault is intermittent or changes
Search technical service bulletins (TSBs) or special service instructions for occupant classification issues for the specific vehicle

Signal parameters

Reference supply typically 5 V (vehicle-specific) to the sensor/module — verify nominal 5 V at the sensor connector power pin
Signal voltage varies with occupant presence (common range 0.0–5.0 V depending on design) — expect a stable value that changes when a weight/occupant is applied
Sensor ground should be near 0 V; check for low-impedance ground
If sensor is resistive-type, nominal resistance and expected change with load are defined in service manual — measure per OEM procedure
Communication lines (if digital) may be LIN/CAN — verify bus communication and lack of bus errors (vehicle-specific)

Diagnostic algorithm

Connect a quality scan tool; record B3692 plus any related codes and freeze frame data; clear codes and attempt to re-create.
Perform visual inspection: seat cushion area, connectors under seat, wiring harness routing, signs of moisture or damage; remove debris and secure connectors.
With ignition on, check SRS fuse(s) and supply voltage at the sensor/module power pin; verify approximately 5 V reference (follow OEM pinout).
Check sensor ground integrity: measure voltage drop or continuity to chassis ground with connectors connected.
Backprobe sensor connector: monitor signal line while placing a known weight or a test load on the seat; verify signal changes and stays within expected range per OEM specs.
Wiggle test: move seat rails, connectors and harness while watching for changes in live data or disappearance/reappearance of the DTC to locate intermittent wiring faults.
If the sensor shows open/short or inconsistent signal, disconnect and measure continuity/resistance of sensor wiring to the SRS module; repair any pin corrosion, broken wires, or harness chafing.
If wiring and power/ground are good but sensor outputs are out of range or nonresponsive, replace the occupant classification sensor/module per service instructions.
After repair or replacement, clear codes, perform any required occupant system calibration or zeroing procedure per factory procedure, then verify code does not return and system behaves normally.
If fault persists with verified good sensor and harness, inspect/replace SRS control module or consult manufacturer-level diagnostics.