B1937 code definition

The B1937 code is manufacturer-specific body code related to air bags. In this case, it means that the engine control module (ECM) has detected a fault with the passenger-side air bag.

What the B1937 code means

A code B1937 will be stored when the ECM has detected an open voltage signal from the passenger-side air bag pressure switch.

What causes the B1937 code?

Several problems may cause a B1937 code including:

  • Clock spring malfunction
  • Open circuit to passenger-side air bag pressure switch
  • Damaged or defective passenger-side air bag pressure switch
  • Passenger-side air bag module malfunction
  • SAS control module malfunction

What are the symptoms of the B1937 code?

Symptoms of a B1937 code may include:

  • Check engine light may illuminate
  • Air bag light may incorrectly illuminate
  • Air bag light may flash
  • Passenger side air bag may not inflate during a crash
  • There may be no symptoms other than a stored B1937 code

How does a mechanic diagnose the B1937 code?

A mechanic may use several methods to diagnose a B1937 trouble code, including:

  • Utilize an OBD-II scanner to check for a stored B1937 trouble code
  • Inspect the driver-side air bag module connector
  • Inspect the clock spring
  • Inspect the wiring harness between the SAS control module and clock spring for short to the power supply
  • Inspect the passenger-side air bag pressure switch
  • Inspect passenger-side air bag module
  • Perform SAS control module DTC inspection

Common mistakes when diagnosing the B1937 code

Detection conditions are for understanding the DTC outline before performing an inspection. Performing an inspection according to only the detection conditions may cause injury due to an operating error, or damage the system. When performing an inspection, it is recommended to always follow the inspection procedure.

How serious is the B1937 code?

Because a vehicle’s safe driving operation can be impacted due to faults that store a B1937 code, this code is considered a potentially serious code. When this code appears, it is recommended to immediately take your vehicle to your local service center or mechanic for repair and diagnosis.

What repairs can fix the B1937 code?

Several repairs can fix a B1937 trouble code and include:

  • Clock spring repair or replacement

  • Replace damaged or defective wiring harness between SAS control module and clock spring

  • Passenger-side airbag module repair or replacement

  • Passenger-side air bag pressure switch repair or replacement

  • SAS control module repair or replacement

Additional information related to a B1937 code

Handling the air bag system components improperly can accidentally deploy the air bag modules and pre-tensioner seat belts, which can seriously injure you and those around you. Always be sure to read the service warnings and cautions before handling the air bag system components. Anything related to air bag repairs can be both difficult and dangerous, and is often best left to professionals for diagnosis and repair. If making any repairs at home, take care with the air bags when removed from the vehicle.

In addition, a technical service bulletin (TSB) may be related to the B1937 trouble code, so it is always recommended to check and see what bulletins may be associated with a particular code prior to diagnosis and repair.

Need help with a B1937 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

This article originally appeared on YourMechanic.com as B1937 OBD-II Trouble Code: Air Bag Passenger Pressure Switch Circuit and was authored by Parker Hill.


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