B1933 code definition
A B1933 trouble code indicates a circuit failure in the passenger side's airbag deployment system.
What the B1933 code means
The driver and passenger airbags are governed by independent circuits. A B1933 code indicates that the circuit for the passenger airbag system is incomplete. If the airbag electronic controller unit (ECU) detects an incomplete circuit, a B1933 code will be stored on the vehicle's computer.
What causes the B1933 code?
An incomplete circuit is most often caused by issues with the electrical wiring. Corroded, disconnected, damaged and otherwise broken wiring will sever the circuit. Faulty components, such as a malfunctioning ECU or sensor, may also be to blame for a B1933 issue.
What are the symptoms of the B1933 code?
If the passenger airbag's related circuit is incomplete, the passenger airbag will not deploy, even if the appropriate impact criteria are met. In addition, a stored B1933 trouble code and illuminated engine lamp will be present for the sake of diagnosing the issue.
How does a mechanic diagnose the B1933 code?
The B1933 code may be first diagnosed by reading the vehicle's onboard computer with an OBD-II code scanner. All wiring related to the passenger airbag circuit should be examined for possible signs of wear or damage. A voltmeter or Autohex device may be used to troubleshoot the source of the circuit break more easily. Any components relating to the passenger airbag, such as the airbag ECU, should be tested for potential signs of faultiness.
Common mistakes when diagnosing the B1933 code
Body-related trouble codes often describe a number of different problems depending on the specific make and model. Make sure you're interpreting the code correctly before proceeding. Check with the vehicle user manual if you're unsure.
How serious is the B1933 code?
If your vehicle is subject to a B1933 code, the passenger airbag should be considered inoperable. This should be considered as a safety hazard to anyone driving on the passenger's side. Although it isn't a threat to the vehicle's drivability, a B1933 should be addressed promptly if the vehicle regularly carries passengers.
What repairs can fix the B1933 code?
The wiring related to the passenger airbag circuit should be checked, repaired or even replaced if necessary. Components in the airbag deployment system (including the ECU) should be checked for signs of malfunction and repaired accordingly. Following any repairs made to address the B1933 code, the vehicle should be retested in order to verify whether the problem has been solved for good.
Additional comments for consideration regarding the B1933 code
In many vehicles, airbag-related circuitry can be found on the passenger's side behind the kick panel. Refer to your vehicle's user manual for specific instructions on where and how to access the airbag system circuits.
Need help with a B1933 code?
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This article originally appeared on YourMechanic.com as B1933 OBD-II Trouble Code: Air Bag Passenger Circuit Open and was authored by Conor Fynes.