B1939 Code - Air Bag Passenger Pressure Switch Circuit Short To Ground Fault
Quick Answer
The B1939 code indicates a problem with the airbag passenger pressure switch circuit, specifically a short to ground fault. Common causes include Damaged wiring or connectors in the passenger pressure switch circuit, Malfunctioning passenger pressure switch, Corrosion or moisture in the airbag system components. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- B1939 indicates Air Bag Passenger Pressure Switch Circuit Short To Ground Fault.
- Common causes
- Common causes include Damaged wiring or connectors in the passenger pressure switch circuit, Malfunctioning passenger pressure switch, Corrosion or moisture in the airbag system components.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code B1939 Description
The B1939 code indicates a problem with the airbag passenger pressure switch circuit, specifically a short to ground fault. This switch is responsible for detecting the presence of a passenger in the front passenger seat and adjusting the airbag deployment accordingly. A short to ground fault means that there is an unintended connection between the switch circuit and the vehicle's ground, which can disrupt the proper functioning of the airbag system.
Common Causes of B1939
- Damaged wiring or connectors in the passenger pressure switch circuit
- Malfunctioning passenger pressure switch
- Corrosion or moisture in the airbag system components
- Faulty airbag control module
- Electrical issues in the vehicle's wiring harness
Symptoms of B1939
- Airbag warning light illuminated on the dashboard
- Airbag system may fail to deploy in a crash
- Inconsistent airbag deployment based on passenger weight
- Fault codes related to airbag system stored in the vehicle's computer
How to Fix B1939
- Diagnose the code using a professional diagnostic tool to pinpoint the exact location of the short to ground fault.
- Inspect the wiring and connectors in the passenger pressure switch circuit for any damage or corrosion. Repair or replace as needed.
- Test the passenger pressure switch to ensure it is functioning correctly. Replace if necessary.
- Check the airbag control module for any faults or malfunctions. Replace if required.
- Clear the fault codes from the vehicle's computer and perform a test to ensure the airbag system is working properly.
Cost to Fix B1939
The typical repair costs for resolving a B1939 code can vary depending on the specific cause of the issue and the extent of the repairs needed. On average, the parts for this repair can range from $100 to $300, while the labor costs can add an additional $150 to $300. Overall, the total cost for addressing this issue could be between $250 and $600. It is important to note that these estimates are rough averages and actual costs may vary based on the factors mentioned earlier.
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Code B1939 Information for Specific Makes
- B1939 Ford — Air Bag Passenger Pressure Switch Circuit Short To Ground Fault
- B1939 Lincoln — Air Bag Passenger Pressure Switch Circuit Short To Ground Fault
- B1939 Mercury — Air Bag Passenger Pressure Switch Circuit Short To Ground Fault
Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service
- Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
- Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
- Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
- Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.
Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.
Frequently Asked Questions about B1939 Code
1. What are common symptoms of OBDII code B1939?
- Common symptoms include the airbag warning light illuminating on the dashboard, the airbag system not functioning properly, and potential loss of passenger-side airbag protection.
2. What causes the B1939 code to indicate an Air Bag Passenger Pressure Switch Circuit Short To Ground Fault?
- The B1939 code is typically triggered by a short circuit to ground in the passenger pressure switch circuit, often caused by damaged wiring, a faulty pressure switch, or a poor connection.
3. How serious is the B1939 code related to the Air Bag Passenger Pressure Switch Circuit Short To Ground Fault?
- This code is serious as it indicates a fault in the passenger-side airbag system, potentially leading to the airbag not deploying in the event of a collision, posing a safety risk to the vehicle occupants.
4. Can I continue driving with the B1939 code present?
- It is not recommended to continue driving with the B1939 code active, as the airbag system's failure to deploy in a crash could increase the risk of injury to passengers.
5. How can I diagnose and repair the B1939 code at home?
- Diagnosing and repairing the B1939 code may require specialized equipment and knowledge. It is advisable to consult a professional mechanic or technician to accurately diagnose and fix the issue.
6. What are the typical repair options for resolving the B1939 code?
- Repair options may include repairing or replacing damaged wiring, replacing the passenger pressure switch, checking and securing connections, and resetting the fault codes using an OBDII scanner.
7. Is it possible to reset the B1939 code without fixing the underlying issue?
- While you can clear the error code temporarily, it is essential to address the root cause of the B1939 code to ensure the airbag system functions correctly and provides adequate safety in case of an accident.
8. Can extreme temperatures or environmental factors trigger the B1939 code?
- Extreme temperatures or environmental conditions can potentially exacerbate existing issues leading to the B1939 code, such as causing wiring insulation to degrade or connections to corrode.
9. Are there any preventive maintenance steps to avoid the B1939 code in the future?
- Regular inspection of the airbag system, checking for any visible damage or wear in wiring and components, and addressing any issues promptly can help prevent the occurrence of the B1939 code.
10. How long does it typically take to repair the B1939 code related to the Air Bag Passenger Pressure Switch Circuit Short To Ground Fault?
- The repair time for the B1939 code can vary depending on the exact cause of the fault and the extent of repairs needed. It is best to consult a professional for an accurate estimate.
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