What Does B1908 Mean?
This code indicates that the airbag control module has detected an abnormal voltage condition on the ground circuit for crash sensor #2. Specifically, the ground wire is showing battery voltage (typically 12+ volts) when it should read near 0 volts, indicating a short to power condition. This fault prevents the crash sensor from functioning properly and typically disables the supplemental restraint system.
Safety Warning
This is a critical safety issue as the airbag system is likely disabled and will not deploy in a collision. The vehicle should not be driven until repairs are completed as occupant protection is severely compromised.
Common Causes
45%
Damaged wiring harness with ground wire shorted to power wire, often from collision damage, rodent damage, or chafing at pinch points
30%
Faulty crash sensor #2 with internal short circuit causing ground terminal to read battery voltage
15%
Corrosion or moisture intrusion in crash sensor connector causing cross-circuit contamination between power and ground pins
10%
Airbag control module internal fault causing misdiagnosis of circuit voltage or internal short condition
Diagnostic Steps
1
Step 1: Perform visual inspection of crash sensor #2 location (typically front bumper area) and wiring harness for obvious physical damage, collision evidence, rodent damage, or wire chafing. Check connector for corrosion, pushed-out pins, or moisture.
2
Step 2: Disconnect crash sensor #2 connector at the sensor. Using a digital multimeter, measure voltage on the ground wire terminal at the vehicle harness side with ignition ON. Reading should be 0V; if battery voltage is present, wiring harness has short to power.
3
Step 3: If battery voltage found in Step 2, trace the sensor wiring harness from sensor location back toward airbag control module, inspecting for pinch points, damaged insulation, or areas where wires contact sharp edges. Pay special attention to areas near the radiator support and fender wells.
4
Step 4: If no voltage found in Step 2, measure resistance between crash sensor ground terminal and known good chassis ground with sensor disconnected. Should read less than 5 ohms. If open circuit or high resistance with no harness damage found, replace crash sensor #2.
5
Step 5: After repair, clear codes and perform airbag system self-test. Road test vehicle and verify code does not return. Confirm airbag warning light extinguishes after successful self-test cycle.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates that the airbag control module has detected an abnormal voltage condition on the ground circuit for crash sensor #2. Specifically, the ground wire is showing battery voltage (typically 12+ volts) when it should read near 0 volts, indicating a short to power condition. This fault ...
The most common cause of B1908 (Air Bag Crash Sensor #2 Ground Circuit Short To Battery) is: Damaged wiring harness with ground wire shorted to power wire, often from collision damage, rodent damage, or chafing at pinch points
Typical repair costs for B1908 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is a critical safety issue as the airbag system is likely disabled and will not deploy in a collision. The vehicle should not be driven until repairs are completed as occupant protection is severely compromised.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1908 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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