B00C8

Code

Generic B — Body

Passenger Seat Occupant Position Sensor B

Brand: Generic

Type: B — Body

Views: UK: 18 EN: 31 RU: 31

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Page language: EN

Causes

Damaged or disconnected occupant position sensor (sensor B) under passenger seat
Corroded or loose connector at the sensor or airbag control module
Broken, chafed or shorted wiring in the seat harness (common at seat hinge)
Water/moisture intrusion into connector or sensor assembly
Failed occupant position sensor electronics
Faulty airbag control module or CAN/LIN communication fault

Symptoms

SRS / Airbag warning lamp illuminated
Passenger airbag disabled or 'passenger airbag off' indicator incorrectly active
Occupant classification unavailable or incorrectly reporting presence/absence
DTC B00C8 stored in the airbag/control module; possibly other SRS-related codes
Occasional or intermittent changes in passenger airbag status with seat movement

What to check

Read and record all SRS/airbag module codes and freeze frame data with a capable scan tool
Confirm whether related occupant classification or airbag codes are present
Visually inspect the passenger seat underside: connectors, wiring loom, clips and grommets for damage or corrosion
Perform a wiggle test of the seat harness and connectors while monitoring live sensor data or codes
Check connectors for bent pins, water intrusion, corrosion and secure locking
Measure reference voltage, signal voltage and ground at the sensor connector per manufacturer spec (see diagnostic steps)

Signal parameters

Analog sensor types: reference (Vref) typically ~5 V (or vehicle specific); signal output generally within 0.5–4.5 V depending on occupant position
Resistance-type sensors: nominal resistance can vary by design (often in the kilo-ohm range) — refer to vehicle-specific values
Digital sensors: occupant status transmitted over CAN or LIN bus as periodic messages; verify presence of occupant classification messages with scan tool
Expected behavior: stable signal when seat is unoccupied, a predictable change when a person or test weight is placed on seat; no intermittent drops to open or short voltage
If signal floats to 0 V or rails to supply, suspect open, short to ground, or short to battery

Diagnostic algorithm

Safety first: follow manufacturer SRS safety procedures. Disable airbag system power (battery negative disconnect) and wait specified time before working near SRS components.
Step 1 — Read codes: Connect a scan tool with SRS/occupant classification capability. Record DTC B00C8 and any related codes or freeze frame data.
Step 2 — Visual inspection: Inspect the passenger seat underside and connector for obvious damage, corrosion, moisture, or disconnected plugs. Check at seat adjuster pivot points.
Step 3 — Connector check: Re-seat the occupant sensor connector(s). Inspect pins for corrosion or damage. Clean and apply dielectric grease if appropriate.
Step 4 — Wiggle/monitor: Reconnect battery per procedure, monitor live occupant position sensor data or SRS status while performing a wiggle test on harness and connectors to reproduce fault.
Step 5 — Electrical check: With service manual reference, backprobe connector and measure Vref, signal and ground with ignition ON (do not probe airbag firing circuits). Compare to expected ranges (see signal_params). Check continuity to airbag ECU and for shorts to ground/battery.
Step 6 — Functional test: Place known test weight(s) or have an assistant sit in seat while observing sensor output or occupant classification messages. Verify proper change and stability of signal.
Step 7 — Isolate: If wiring and connector tests pass but signal is faulty, consider replacing the passenger seat occupant position sensor (B) or the seat cushion module as applicable. If multiple sensors or modules present, swap identical components only if allowed by manufacturer and safe.
Step 8 — Relearn/Calibration: After repair or replacement, clear codes and perform any required occupant classification system learning/calibration procedure per manufacturer.
Step 9 — Verify: Confirm code does not return, and that passenger airbag enable/disable logic and SRS lamp behave correctly during tests and a short road test.
If unsure at any step, consult the vehicle manufacturer service manual or a qualified SRS technician.

Likely causes

Connector pin corrosion or poor connection at seat harness (most common)
Wiring break at seat movement pivot (common failure point)
Sensor unit failed due to impact or water ingress
Sensor not seated or mechanically shifted (seat cushion removal)
Intermittent CAN/LIN communications or module internal fault (less common)

Fault status

⚠️ Status

Passenger Seat Occupant Position Sensor B: circuit malfunction or implausible signal. Passenger occupant classification may be unavailable; SRS/airbag lamp illuminated. Passenger airbag may be disabled until fault cleared and system verified.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours