B2050

Code

Generic B — Body

Occupant Classification System Sensor Circuit Malfunction

Brand: Generic

Type: B — Body

Views: UK: 7 EN: 5 RU: 6

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open, short or high-resistance wiring between the OCS sensor and the classification/module
Corroded, loose or damaged connector at the sensor or module
Failed occupant classification sensor (load cell/pressure sensor/strain gauge)
Failed occupant classification/module (control unit) or software fault
Water intrusion or contamination in seat cushion or connector
Intermittent connection due to chafed wiring in seat harness

Symptoms

Airbag warning or supplemental restraint system (SRS) light on
Passenger airbag status indicator shows 'off' or 'unavailable' incorrectly
DTC B2050 stored (may be accompanied by other SRS/communication codes)
Intermittent or inconsistent passenger detection
Possible disablement of passenger airbag for safety

What to check

Read freeze frame and full DTC list with a capable scan tool; note related SRS or communication codes
Visually inspect seat, connectors and harness for damage, corrosion, signs of water, or aftermarket modifications
Verify proper connector seating and locked terminals at the sensor and module
Check vehicle battery voltage and perform a battery/charging system baseline
Measure reference supply voltage and ground at the sensor connector
Check for presence of expected CAN/LIN messages using a diagnostic scanner or scope (if applicable)

Signal parameters

Reference (supply) voltage typically 5 V (varies by manufacturer); should be stable within ±0.2 V
Ground near 0 V with low resistance to chassis ground (milliohms to a few ohms)
Signal output voltage from sensor typically 0.5–4.5 V depending on occupant/load (refer to OEM spec)
Load cell/strain gauge resistance (if applicable) — typically measured in ohms or kilohms per OEM data
CAN/LIN network traffic: OCS module should transmit occupant status messages at defined intervals (verify with scanner)
No short to battery (VB) or short to ground on signal wires; typical short detection thresholds vary by OEM

Diagnostic algorithm

Connect a capable OBD/SRS scan tool. Read and record all stored and pending codes plus freeze frame data. Note any communication or related SRS codes.
Perform visual inspection of the passenger seat cushion, connectors under the seat, and wiring harness for damage, corrosion, water intrusion, or signs of prior repairs.
With battery charged, backprobe the sensor connector. Verify reference supply voltage, ground continuity and signal voltage while the seat is unoccupied and with a known weight (per OEM procedure). Compare to service values.
If reference or ground is out of range, trace and repair wiring to power source or chassis ground. Repair or replace damaged connectors or pins.
If voltages are present but signal is out of spec or intermittent, inspect/measure continuity and resistance of sensor circuits. If the sensor shows open/short or out-of-spec resistance, replace the sensor assembly.
Check for CAN/LIN communications. If the OCS module is not communicating, diagnose CAN/LIN network (check bus voltage, termination, and continuity). Repair bus faults or module power/ground issues.
Perform wiggle/operation tests while monitoring live sensor data to find intermittent faults. Repair chafed wiring, secure connectors, and re-route harnesses away from pinch points.
After repairs, clear codes and perform system-specific occupant classification calibration or zeroing if required by OEM procedures. Verify functionality with the diagnostic tool and through test scenarios.
If wiring and sensor bench checks are good and the fault remains, consider replacing the OCS control module per OEM diagnostic flow. Follow module programming/initialization steps after replacement.

Likely causes

Broken wire or pinched harness under the seat
Corrosion or bent pins at the seat sensor connector
Faulty seat cushion sensor assembly (strain gauge/load cell)
Bad ground or missing reference voltage to sensor
Loss of CAN/LIN communication between OCS module and airbag module
Previous seat repair or aftermarket equipment disturbed the harness

Fault status

⚠️ Status

Occupant Classification System sensor circuit malfunction — electrical fault (open/short/intermittent), sensor failure, or communication error affecting occupant detection.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours