B1937 — Air Bag Passenger Pressure Switch Circuit Open #

The label for this DTC (Diagnostic Trouble Code) may vary depending on the manufacturer.

• Air Bag Passenger Pressure Switch Circuit Open (Ford, GM, Chrysler, Toyota, Honda)
• Passenger Seat Pressure Sensor Circuit Open (Hyundai, Kia)
• Occupant Classification System Sensor Circuit Open (Nissan, Infiniti)

Summary for code B1937 #

B1937 is a specific trouble code that indicates an open circuit in the passenger air bag pressure switch. This switch is part of the vehicle’s Supplemental Restraint System (SRS), commonly known as the air bag system. An open circuit means there is a break or disconnection somewhere in the electrical pathway, preventing the system from accurately detecting whether a passenger is present or not. When this code appears, the vehicle’s air bag control module is unable to receive vital information about the passenger seat occupancy, which can affect air bag deployment in a crash. The code is most commonly triggered by wiring issues, a faulty pressure sensor, or connector problems under the passenger seat.

Frequent symptoms for code B1937 #

When B1937 is present, you may notice various warning signs indicating an issue with the passenger air bag system. These symptoms are designed to alert you that the air bag system may not function as intended in the event of an accident.

• Air bag warning light illuminated on the dashboard
• Passenger air bag status indicator showing “OFF” regardless of seat occupancy
• Chime or audible alert when starting the vehicle
• Possible SRS system warning messages on the instrument panel

Probable causes for code B1937 #

The most common causes for B1937 are related to electrical or sensor issues within the air bag system. The following is a prioritized list of likely reasons behind this fault:

1. Damaged or disconnected wiring under the passenger seat
2. Faulty passenger seat pressure sensor (also known as a weight sensor or occupant classification sensor)
3. Loose, corroded, or contaminated electrical connectors at the sensor or SRS module
4. Faulty SRS control module (less common, but possible)
5. Incorrectly installed seat components after servicing or cleaning

Step-by-step diagnosis for code B1937 #

Diagnosing B1937 requires a logical approach and attention to detail. Follow these steps to pinpoint the exact cause:

• Step 1: Retrieve all stored codes and freeze-frame data using a scan tool. Clear codes and see if B1937 returns immediately.
• Step 2: Inspect the passenger seat area for visible damage, loose wires, or disconnected connectors. Gently move the seat to check for intermittent connections.
• Step 3: Disconnect the battery and wait at least 10 minutes (to prevent accidental air bag deployment) before inspecting or disconnecting SRS connectors.
• Step 4: With the battery still disconnected, check the passenger pressure sensor connector for corrosion, bent pins, or contamination. Clean and reconnect as needed.
• Step 5: Test wiring continuity between the sensor and SRS module using a multimeter. Look for open circuits or high resistance.
• Step 6: If wiring is intact, test the pressure sensor itself according to the OEM (Original Equipment Manufacturer) service manual procedures. Replace if out of specification.
• Step 7: If all else checks out, consider further diagnosis of the SRS module or consult a qualified technician with advanced diagnostic tools.

Possible repairs for code B1937 #

Repairs should target the specific cause found during diagnosis. Common solutions include:

• Repair or replace damaged wiring or connectors under the passenger seat
• Replace the faulty passenger pressure sensor (weight sensor/occupant classification sensor)
• Clean and securely reconnect all seat-related SRS connectors
• Reinstall or recalibrate the seat cushion or pressure mat if recently serviced
• Replace or reprogram the SRS control module (if verified defective)

Can you drive with code B1937? #

It is not recommended to drive with code B1937 present. While the car may operate normally, your passenger air bag system may not deploy correctly in the event of a collision. This compromises the safety of anyone sitting in the front passenger seat. Until the issue is fixed, the air bag system may either fail to deploy or deploy incorrectly, increasing the risk of injury. Have the problem diagnosed and repaired as soon as possible.

Vehicles most commonly affected by code B1937 #

B1937 is seen across a range of vehicles, especially those with advanced occupant classification systems. The following makes and models report this code more often, usually in model years 2000s and newer:

• Ford (Focus, Fusion, F-150, Explorer)
• Chevrolet (Malibu, Silverado, Equinox)
• Chrysler/Jeep/Dodge (Sebring, Grand Cherokee, Ram)
• Toyota (Camry, Corolla, RAV4)
• Honda (Accord, Civic, CR-V)
• Hyundai/Kia (Sonata, Elantra, Sorento)
• Nissan (Altima, Sentra, Rogue)

Common mistakes & best practices for code B1937 #

Misdiagnosis and improper repair attempts are frequent with SRS faults. Here’s what to watch out for:

• Ignoring the SRS warning light or clearing codes without investigating the root cause
• Failing to disconnect the battery before working on SRS components, risking accidental air bag deployment
• Overlooking connector issues under the seat, especially after moving or cleaning the seat
• Replacing expensive sensors or modules without thoroughly checking wiring and connectors first
• Not following OEM service procedures for testing and replacement

Express FAQ — B1937 #

Still have questions? Here are fast answers to the most common concerns:

• Q: Will my air bag still work if I ignore B1937?
  A: The passenger air bag may not deploy at all, or could deploy improperly, putting occupants at risk.
• Q: Can I clear the code to fix the problem?
  A: Clearing the code without repairing the underlying issue will not restore air bag functionality; the warning light will likely return.