B00B9

Code

Generic B — Body

Driver Seat Occupant Position Sensor C

Brand: Generic

Type: B — Body

Views: UK: 27 EN: 41 RU: 27

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open, short or high resistance in the sensor C wiring or connector
Corroded, bent or loose seat wiring connector or pins
Failed occupant position sensor pad/mat (sensor C element)
Faulty occupant classification/airbag control module or internal connector
Water/moisture ingress into seat cushion or connector
Poor or missing ground/reference voltage to the sensor

Symptoms

SRS / Airbag warning lamp illuminated
Occupant classification system disabled or showing incorrect occupant status
Possible disablement of passenger airbag or seatbelt pretensioner logic
Diagnostic trouble code stored in SRS/occupant classification module
No obvious mechanical symptom at the seat other than electrical warning

What to check

Read all SRS/occupant classification codes and freeze-frame data with a capable scan tool
Check vehicle battery voltage and system power (low voltage can cause false faults)
Visually inspect the driver seat underside and connectors for damage, corrosion, or water
Perform a wiggle test on the seat harness while monitoring live data for changes
Check continuity and resistance of the sensor C circuit from sensor connector to the module
Verify reference voltage (typically 5V) and ground at the sensor connector with ignition on

Signal parameters

Reference supply: typically 5 V reference from occupant classification module (verify exact spec with OEM)
Signal level: sensor output commonly in the 0.0–5.0 V range; exact idle and loaded voltages vary by design
Resistance: sensor pad elements may show ohm-level to kiloohm values depending on construction (refer to manufacturer specs)
Behavior: signal should change smoothly with applied load/position; intermittent open or short will show erratic or fixed readings
CAN/Circuit: some systems send processed data over SRS/CAN bus — raw values/specs are manufacturer-specific

Diagnostic algorithm

Use a qualified SRS-capable scan tool to read DTC B00B9 and any related codes; record freeze frame and live data.
Verify battery/system voltage is within specification; low voltage can create false SRS faults.
Visually inspect the driver seat cushion, underside, and connectors for water, corrosion, damage, or pin push-out. Repair any physical damage.
With ignition ON (but engine off per safety procedures), backprobe the seat sensor C connector: confirm reference voltage (≈5V) and good ground. If reference or ground missing, trace wiring to module.
Measure sensor C signal voltage and resistance. While observing the scan tool/live data, apply pressure to the seat cushion or place a test weight; sensor output should change. If it does not change or is outside expected range, suspect sensor or open/short.
Perform continuity and resistance checks from the seat connector to the occupant classification/SRS module. Repair any opens, shorts, or high-resistance joints. Pay attention to common break points where harness passes through seat frame.
If wiring and connectors are good but sensor C still defective, replace the seat cushion sensor element or entire seat sensor assembly per OEM procedure.
If replacement was performed or connectors repaired, clear codes and perform the required occupant classification/airbag module relearn/calibration procedure with a factory-capable scan tool.
If code persists after sensor and wiring repair and proper calibration, consider testing/replacing the occupant classification / SRS control module or consult manufacturer technical service information.

Likely causes

Damaged or disconnected harness at the driver seat connector
Corroded pins or poor mating at the sensor/module connector
Failed sensor element in the seat cushion (sensor C)
Intermittent wiring break caused by seat movement
SRS control module internal fault or software error

Fault status

⚠️ Status

SRS/Occupant Classification fault detected for Driver Seat Occupant Position Sensor C. The fault may be stored or active; SRS warning lamp may be illuminated. Requires wiring/sensor checks and possible recalibration.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours