What Does B00B9 Mean?
This code indicates the Body Control Module (BCM) has detected a malfunction in the driver seat occupant position sensor 'C', which is part of the seat occupancy and position detection system. This sensor is typically used for airbag deployment calibration, seatbelt reminder systems, and advanced safety features that adjust restraint systems based on occupant position. The 'subfault' designation suggests an intermittent signal, out-of-range reading, or internal sensor circuit issue rather than a complete failure.
Common Causes
45%
Faulty or degraded position sensor 'C' in seat cushion or seat track assembly
30%
Damaged, corroded, or loose wiring harness connector at sensor 'C' location
15%
Short circuit or open circuit in sensor 'C' wiring between sensor and BCM
10%
Body Control Module internal fault or calibration issue
Diagnostic Steps
1
Step 1: Perform visual inspection of driver seat area, checking for visible damage, foreign objects interfering with seat movement, or signs of liquid intrusion that may affect sensors embedded in seat cushion or track
2
Step 2: Access sensor 'C' connector under driver seat (typically located in seat track or cushion frame), inspect for corrosion, bent pins, water damage, or loose connection, and clean/reseat connector
3
Step 3: Using a digital multimeter, backprobe sensor 'C' connector and verify power supply (typically 5V reference) and ground circuit continuity with BCM connector unplugged, checking for opens or shorts to ground
4
Step 4: Measure sensor 'C' output signal voltage while manually moving seat through full range of positions, comparing readings to manufacturer specifications (typically 0.5-4.5V variable range)
5
Step 5: Check wiring harness continuity between sensor 'C' connector and BCM connector pins, and perform resistance test on sensor internal circuit (typically 1-10k ohms depending on position)
6
Step 6: If all circuits test normal, replace sensor 'C' and perform BCM relearn/calibration procedure, then clear codes and verify repair with test drive and seat position cycling
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a malfunction in the driver seat occupant position sensor 'C', which is part of the seat occupancy and position detection system. This sensor is typically used for airbag deployment calibration, seatbelt reminder systems, and advanced sa...
The most common cause of B00B9 (Driver Seat Occupant Position Sensor "C" (Subfault)) is: Faulty or degraded position sensor 'C' in seat cushion or seat track assembly
Typical repair costs for B00B9 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is generally safe to drive, but airbag deployment may not be optimally calibrated for driver position, potentially affecting restraint system effectiveness in a collision. Seatbelt reminder and advanced safety features may also be compromised. Repair should be completed within 1-2 weeks for optimal safety system function.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B00B9 to identify the root cause.
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Quick Info
Category
Body
System
Occupant Detection and Restraint System
Difficulty
Type
Generic (SAE)
Recommended Tools
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