What Does B1937 Mean?
This code indicates the air bag control module has detected an open circuit in the passenger seat occupant classification system pressure switch. This switch is part of the passenger seat weight sensor system that determines whether the passenger airbag should deploy based on seat occupancy. The control module cannot receive proper signal from the pressure sensor, preventing proper operation of the passenger airbag deployment logic.
Safety Warning
This is a critical safety concern as the passenger airbag may not deploy properly or may deploy inappropriately based on occupant weight classification failure. The airbag warning light will remain illuminated and the vehicle should not be driven with passengers until repaired, as airbag system reliability is compromised.
Common Causes
35%
Damaged or disconnected wiring harness under passenger seat, often from seat movement or obstruction
30%
Faulty passenger seat occupant classification sensor (pressure bladder or mat sensor)
20%
Corroded or loose electrical connector at seat sensor or control module
10%
Failed airbag control module internal circuitry for pressure sensor monitoring
5%
Damaged seat frame or mounting bracket causing sensor misalignment or wire pinching
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger seat area, checking for any objects wedged under seat, damage to seat cover, or visible wiring damage. Remove seat covers if necessary to access sensor mat and connectors.
2
Step 2: Using a digital multimeter, check for continuity and resistance in the pressure sensor circuit from the sensor connector to the airbag control module connector. Verify readings against manufacturer specifications (typically 1-10k ohms when unoccupied).
3
Step 3: Inspect all electrical connectors under passenger seat for corrosion, bent pins, or loose connections. Clean connectors with electrical contact cleaner and verify secure mating. Check connector lock mechanisms.
4
Step 4: With ignition off and battery disconnected, check wiring harness routing under seat for pinch points, chafing, or damage from seat rail movement. Wiggle test wires while monitoring continuity.
5
Step 5: If wiring and connectors are intact, test the pressure sensor itself by applying known weight (50-75 lbs) on passenger seat while monitoring sensor signal voltage or resistance change with multimeter.
6
Step 6: Clear codes, reconnect all components, perform airbag system initialization procedure per manufacturer specifications, and verify code does not return. Test system functionality with varying seat loads.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates the air bag control module has detected an open circuit in the passenger seat occupant classification system pressure switch. This switch is part of the passenger seat weight sensor system that determines whether the passenger airbag should deploy based on seat occupancy. The con...
The most common cause of B1937 (Air Bag Passenger Pressure Switch Circuit Open) is: Damaged or disconnected wiring harness under passenger seat, often from seat movement or obstruction
Typical repair costs for B1937 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is a critical safety concern as the passenger airbag may not deploy properly or may deploy inappropriately based on occupant weight classification failure. The airbag warning light will remain illuminated and the vehicle should not be driven with passengers until repaired, as airbag system reliability is compromised.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1937 to identify the root cause.
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Quick Info
Category
Body
System
Supplemental Restraint System (SRS/Airbag System)
Difficulty
Type
Manufacturer
Recommended Tools
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