What Does B1699 Mean?
This code indicates the Body Control Module (BCM) has detected a short to ground condition in the passenger seat occupancy sensor circuit. This sensor is part of the Supplemental Restraint System (SRS) and determines if the passenger seat is occupied to control airbag deployment logic. The BCM has identified that circuit voltage is being pulled to ground abnormally, preventing proper occupancy detection.
Common Causes
40%
Damaged or chafed wiring harness under passenger seat causing short to chassis ground
30%
Faulty passenger seat occupancy sensor/mat with internal short circuit
20%
Corroded or moisture-damaged connector pins at seat occupancy sensor
10%
Failed Body Control Module with internal circuit fault
Diagnostic Steps
1
Step 1: Perform visual inspection under passenger seat for obvious wire damage, pinched harnesses between seat rails, or chafed insulation contacting metal frame. Check seat connector for corrosion, pushed-out pins, or moisture intrusion.
2
Step 2: Disconnect passenger seat occupancy sensor connector and measure resistance between sensor signal wire and ground using digital multimeter. Should read infinite resistance (open circuit); any continuity indicates short to ground in sensor or wiring.
3
Step 3: With sensor disconnected, measure resistance between BCM-side harness signal wire and chassis ground. Infinite resistance indicates sensor is faulty; continuity indicates wiring harness has short to ground between sensor and BCM.
4
Step 4: If wiring harness shows short, trace wire routing under carpet and seat tracks, checking for damage points. Use continuity testing to isolate fault location by testing at intermediate connectors if accessible.
5
Step 5: After repair (sensor replacement or wiring repair), clear codes, cycle ignition, test occupancy sensor function by placing 50+ pound weight on seat and verify proper operation with scan tool sensor data display.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a short to ground condition in the passenger seat occupancy sensor circuit. This sensor is part of the Supplemental Restraint System (SRS) and determines if the passenger seat is occupied to control airbag deployment logic. The BCM has i...
The most common cause of B1699 (Passenger's Seat Occupied Switch Circuit Short to Ground) is: Damaged or chafed wiring harness under passenger seat causing short to chassis ground
Typical repair costs for B1699 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is drivable but passenger airbag may not deploy correctly or may be deactivated when seat is occupied. This creates significant safety risk for front passengers and should be repaired promptly to ensure proper airbag function.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1699 to identify the root cause.
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Quick Info
Category
Body
System
Supplemental Restraint System (SRS) / Occupant Detection
Difficulty
Type
Manufacturer
Recommended Tools
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