What Does B1672 Mean?
This code indicates the Body Control Module (BCM) has detected a fault in the driver seat occupancy sensor circuit. The sensor, typically a pressure-sensitive mat or weight sensor integrated into the driver seat, is used to determine if the seat is occupied for seatbelt warning systems, airbag deployment logic, and other safety features. The BCM has identified an electrical circuit malfunction such as an open circuit, short circuit, or sensor failure that prevents proper occupancy detection.
Common Causes
35%
Faulty or damaged seat occupancy sensor/mat inside driver seat cushion
30%
Damaged, chafed, or broken wiring harness under driver seat from movement or seat adjustment
20%
Corroded or loose electrical connector at seat sensor or BCM interface
10%
Failed Body Control Module (BCM) with internal circuit fault
5%
Seat frame grounding issue affecting sensor circuit return path
Diagnostic Steps
1
Step 1: Visually inspect the wiring harness under the driver seat for obvious damage, chafing against seat rails, or pinched wires. Check all connectors for corrosion, moisture, or loose connections at the seat sensor and BCM.
2
Step 2: Using a digital multimeter, backprobe the seat occupancy sensor connector (with it connected) and verify reference voltage from the BCM (typically 5V or 12V depending on manufacturer) with ignition on.
3
Step 3: Disconnect the seat occupancy sensor connector and measure resistance across sensor terminals with no weight on seat, then with 50+ lbs applied to driver seat. Compare readings to manufacturer specifications (typically should show change in resistance or switch state).
4
Step 4: Check continuity of all wires between the seat sensor connector and BCM connector using a wiring diagram. Look for opens, shorts to ground, or shorts to voltage (should show proper continuity with no shorts).
5
Step 5: If wiring and sensor test normal, monitor live data stream for seat occupancy status while applying and removing weight from seat to verify BCM is receiving proper signal changes.
6
Step 6: Clear codes, perform occupancy sensor relearn/calibration procedure if available in scan tool functions, cycle ignition, and verify repair by monitoring for code return during test drive.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a fault in the driver seat occupancy sensor circuit. The sensor, typically a pressure-sensitive mat or weight sensor integrated into the driver seat, is used to determine if the seat is occupied for seatbelt warning systems, airbag deplo...
The most common cause of B1672 (Seat Driver Occupied Input Circuit Failure) is: Faulty or damaged seat occupancy sensor/mat inside driver seat cushion
Typical repair costs for B1672 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive, but seatbelt warning systems and airbag deployment logic may be affected. The airbag system may default to activated mode regardless of seat occupancy, or seatbelt chimes may not function properly. Repair should be completed soon to ensure proper safety system operation.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1672 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Safety Systems
Difficulty
Type
Manufacturer
Recommended Tools
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