What Does B1905 Mean?
This code indicates the airbag control module has detected an abnormal voltage condition on the crash sensor #2 circuit, specifically a short to battery voltage (12V+). The airbag control module monitors the crash sensor feed and return circuits for proper voltage levels, and when it detects battery voltage where there should be a lower reference voltage, it sets this fault code. This compromises the airbag system's ability to properly detect crash events and may prevent airbag deployment.
Safety Warning
This is a critical safety system fault that may prevent airbags from deploying in a crash or cause unintended deployment. The vehicle should not be driven until repaired, and airbag warning light will remain illuminated indicating system is non-functional. Immediate professional diagnosis and repair is required.
Common Causes
45%
Damaged wiring harness with exposed conductors contacting power source, often from previous collision damage or improper repairs
30%
Failed crash sensor #2 with internal short to voltage circuit
15%
Corroded or damaged connector terminals at crash sensor allowing moisture intrusion and creating voltage path
10%
Faulty airbag control module with internal circuit failure creating false short-to-battery condition
Diagnostic Steps
1
Step 1: Perform visual inspection of crash sensor #2 location (typically in front crush zones near radiator support) for physical damage, bent mounting brackets, or evidence of previous collision damage. Check sensor mounting and connector for corrosion, water intrusion, or damage.
2
Step 2: Disconnect crash sensor #2 connector and inspect pins for corrosion, bent terminals, or debris. Using a digital multimeter, measure resistance between sensor feed and return circuits to ground - should read open circuit (OL) with sensor disconnected. If continuity to battery voltage exists, wiring is shorted.
3
Step 3: With sensor disconnected, check voltage at harness connector feed circuit - should read 0V with ignition on. If 12V present, trace wiring from sensor location back toward airbag control module looking for chafed insulation, pinched wires, or contact with hot circuits.
4
Step 4: If wiring checks good, reconnect sensor and backprobe connector terminals with multimeter set to DC voltage. Monitor feed and return circuits while gently moving harness - voltage should remain stable at approximately 2.5-5V depending on manufacturer. Fluctuations indicate intermittent short.
5
Step 5: If no wiring faults found, replace crash sensor #2 and retest. Clear codes and perform airbag system self-test. If code returns immediately, suspect airbag control module internal fault requiring module replacement and programming.
Estimated Repair Cost
$200 - $1,200
Parts + labor, varies by vehicle and location
This code indicates the airbag control module has detected an abnormal voltage condition on the crash sensor #2 circuit, specifically a short to battery voltage (12V+). The airbag control module monitors the crash sensor feed and return circuits for proper voltage levels, and when it detects battery...
The most common cause of B1905 (Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery) is: Damaged wiring harness with exposed conductors contacting power source, often from previous collision damage or improper repairs
Typical repair costs for B1905 range from $200 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is a critical safety system fault that may prevent airbags from deploying in a crash or cause unintended deployment. The vehicle should not be driven until repaired, and airbag warning light will remain illuminated indicating system is non-functional. Immediate professional diagnosis and repair is required.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1905 to identify the root cause.
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Quick Info
Category
Body
System
Supplemental Restraint System (SRS/Airbag)
Difficulty
Type
Manufacturer
Recommended Tools
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