B1905 — Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery #

Note: The wording of this code may differ depending on the vehicle manufacturer (OEM). Always refer to your repair manual for model-specific terminology.

• Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery (Ford, Mazda, Lincoln)
• Passenger Airbag Sensor 2 Circuit Shorted to Voltage (Toyota, Lexus)
• Front Impact Sensor Circuit High (General Motors, Chevrolet, GMC)

Summary of DTC B1905 #

The B1905 diagnostic trouble code (DTC) indicates a problem detected in the electrical circuit of the crash sensor #2, specifically a short to battery voltage. The crash sensor, also known as an impact sensor, is a critical part of the Supplemental Restraint System (SRS), which manages airbag deployment. When the control module finds that the feed or return circuit for sensor #2 is receiving excessive voltage, it registers this code and typically disables the affected airbag for safety reasons. This code is considered serious because it may compromise airbag function in an accident. Proper diagnosis and repair are essential to restore full SRS protection.

Common Symptoms for B1905 #

A B1905 code usually triggers visible and audible warnings, as the airbag system is highly safety-critical. You might notice:

• Airbag warning light illuminated on the dashboard
• Warning chimes or messages (e.g., “SRS Fault” or “Airbag System Malfunction”)
• Potentially, the passenger airbag is disabled
• No other drivability issues; the vehicle runs normally
• In rare cases, a persistent “Service Airbag” reminder that won’t clear

Most Likely Causes of B1905 #

The underlying reasons for a B1905 code almost always involve electrical issues. The most common causes, in decreasing order of likelihood, are:

1. Damaged wiring harness to crash sensor #2 (chafed, pinched, or corroded wires)
2. Connector issues (loose, corroded, or water intrusion at the sensor plug)
3. Failed crash sensor #2 (internal electrical short)
4. Faulty airbag/SRS control module (rare, but possible)

Step-by-Step Diagnosis for B1905 #

Diagnosing a B1905 requires patience and the right tools. Here’s a proven systematic approach:

1. Verify the code with a scan tool and record all stored/active SRS codes.
2. Check technical service bulletins (TSBs) for your vehicle—some models have known connector or wiring issues in this area.
3. Visually inspect the wiring harness and connector at crash sensor #2 for damage, corrosion, or water.
4. Disconnect the vehicle battery and wait at least 10 minutes before working on the SRS system (to prevent accidental deployment).
5. Test for voltage at the sensor feed/return wires with a multimeter: there should be no battery voltage present when the system is at rest.
6. Check for continuity and resistance in the wires between the sensor and the SRS module.
7. Substitute a known-good sensor if possible, to rule out sensor failure.
8. If all else checks out, suspect the SRS module itself.

Possible Repairs for B1905 #

Once the root cause is identified, repairs should directly address the faulty component. Typical fixes include:

• Repairing or replacing damaged wiring (splicing, soldering, or replacing harness sections as needed)
• Cleaning or replacing the crash sensor #2 connector (use dielectric grease to prevent future corrosion)
• Replacing crash sensor #2 with a new, OEM-quality sensor
• Replacing the SRS/airbag control module (only if all other possibilities are ruled out)
• Clearing the code and retesting after repairs

Is It Safe to Drive With Code B1905? #

Driving with code B1905 is NOT recommended. When this code is set, the airbag system may be partially or completely disabled. In the event of a collision, some airbags might not deploy, putting occupants at risk of injury. Drive only to a repair facility and avoid using the vehicle until the SRS system is fully operational again.

Vehicles Most Commonly Affected by B1905 #

This code is most frequently reported on vehicles from manufacturers who use similar SRS sensor architectures. Some of the most frequently affected models include:

• Ford (Focus, Fusion, Escape, Explorer, F-Series)
• Mazda (3, 6, CX-5, Tribute)
• Lincoln (MKZ, Navigator)
• Toyota (Corolla, Camry, RAV4)
• Chevrolet (Silverado, Malibu)
• GMC (Sierra, Acadia)

Frequent Mistakes & Best Practices for B1905 #

Misdiagnosis is common due to the nature of SRS systems. To avoid wasted time and money, keep these in mind:

• Never attempt repairs on the SRS system without disconnecting the battery and waiting for the system to discharge.
• Don’t replace the sensor before performing a full inspection of the wiring and connectors.
• Always use OEM or quality aftermarket parts for SRS repairs.
• Don’t ignore technical service bulletins (TSBs) related to airbag wiring or connectors.
• After repair, always clear codes and verify SRS system operation with a scan tool.

Quick FAQ for B1905 #

Still have questions? Here are fast answers to what most car owners and techs ask:

• Can I reset B1905 by disconnecting the battery?
  No. Simply disconnecting the battery rarely clears SRS codes. The underlying issue must be repaired, then the code cleared with a scan tool.
• Will my airbag deploy by accident if I drive with this code?
  Unlikely. The system is designed to disable the affected airbag to prevent accidental deployment when a fault is detected. However, other airbags may not function as intended in a crash.