What Does B00C8 Mean?
This code indicates that the Body Control Module (BCM) has detected a malfunction in the passenger seat occupant position sensor 'B', which is part of the Occupant Classification System (OCS). This sensor works in conjunction with the airbag system to determine passenger position, weight distribution, and seating posture to optimize airbag deployment. The 'subfault' designation suggests a secondary or intermittent issue with sensor circuit voltage, signal range, or calibration drift rather than a complete failure.
Common Causes
45%
Faulty or damaged seat position sensor mat or pressure sensor embedded in passenger seat cushion
30%
Corroded, loose, or damaged wiring connector at seat sensor harness under passenger seat
15%
Damaged or chafed wiring between sensor and BCM due to seat movement or track interference
10%
BCM software calibration error or internal module fault in occupant detection system
Diagnostic Steps
1
Step 1: Perform visual inspection under passenger seat for damaged wiring, loose connectors, or foreign objects interfering with sensor mat. Check seat track area for pinched or chafed harness wiring and verify connector security at sensor base.
2
Step 2: Using a digital multimeter, test sensor 'B' voltage signal at the harness connector (typically 5V reference voltage). Check for proper ground continuity (less than 0.5 ohms to chassis ground) and verify signal wire has no short to ground or power.
3
Step 3: With seat unoccupied, access live sensor data through scan tool to observe position sensor 'B' output values. Apply controlled pressure to different seat areas and verify sensor responds with appropriate voltage changes (typically 0.5V to 4.5V range depending on pressure).
4
Step 4: Check for Technical Service Bulletins (TSBs) related to occupant sensor calibration. If sensor readings are erratic or out of range, disconnect battery for 5 minutes, then perform BCM/OCS system relearn procedure per manufacturer specifications.
5
Step 5: If all electrical tests pass but code persists, replace occupant position sensor 'B' assembly and perform mandatory system calibration and verification test with scan tool to ensure proper airbag system integration.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected a malfunction in the passenger seat occupant position sensor 'B', which is part of the Occupant Classification System (OCS). This sensor works in conjunction with the airbag system to determine passenger position, weight distributio...
The most common cause of B00C8 (Passenger Seat Occupant Position Sensor "B" (Subfault)) is: Faulty or damaged seat position sensor mat or pressure sensor embedded in passenger seat cushion
Typical repair costs for B00C8 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is generally safe to drive, but the passenger airbag system may default to 'ON' or 'OFF' mode regardless of occupant status, potentially deploying inappropriately for small passengers or failing to deploy when needed. Repair should be completed within 1-2 weeks to ensure proper airbag system functionality.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B00C8 to identify the root cause.
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Quick Info
Category
Body
System
Supplemental Restraint System (SRS) / Occupant Classification System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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