What Does B2440 Mean?
B2440 indicates the Body Control Module (BCM) has detected a fault with the passenger side impact crash sensor mounting or securing system. This code means the sensor is not properly secured to the vehicle structure, has been dislodged, or the mounting bracket has failed. The side crash sensor is a critical component of the Supplemental Restraint System (SRS) that detects lateral impacts to deploy side airbags and curtains at the correct timing.
Safety Warning
This is a critical safety system fault that may prevent side airbags from deploying correctly in a lateral collision. The vehicle should not be driven until repaired as occupant protection is compromised. Repair should be completed immediately.
Common Causes
45%
Physical damage to sensor mounting bracket or sensor dislodged from mount due to previous collision, improper installation, or corrosion
30%
Loose or broken mounting bolts/fasteners allowing sensor movement or improper positioning
15%
Internal accelerometer failure within the sensor registering as mounting fault due to incorrect calibration readings
10%
Wiring harness connector damaged or corroded causing intermittent communication that BCM interprets as mounting issue
Diagnostic Steps
1
Step 1: Perform physical inspection of passenger side B-pillar or door-mounted side impact sensor location. Check for visible damage, loose mounting, missing bolts, or sensor misalignment. Verify sensor is securely fastened with proper torque specifications (typically 8-12 Nm).
2
Step 2: Remove sensor and inspect mounting bracket for cracks, deformation, or corrosion. Check sensor mounting surface for proper contact and alignment. Verify mounting holes are not stripped or damaged.
3
Step 3: Inspect sensor electrical connector for corrosion, bent pins, or damage. Disconnect connector and measure resistance across sensor terminals (typical range 2-5 ohms depending on manufacturer). Check wiring harness for chafing or damage between sensor and BCM.
4
Step 4: Using scan tool, monitor side impact sensor live data while gently tapping sensor and mounting area with rubber mallet. Observe for erratic readings or communication dropouts that would indicate loose mounting or internal sensor failure.
5
Step 5: If physical mounting is secure, perform sensor calibration procedure using manufacturer-specific software. Replace sensor if calibration fails or if physical damage is present. Clear codes and verify proper mounting torque before road test.
6
Step 6: After repair, perform SRS system self-test and verify airbag warning light extinguishes. Confirm no additional crash sensor codes are present and that sensor responds correctly to system diagnostics.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
B2440 indicates the Body Control Module (BCM) has detected a fault with the passenger side impact crash sensor mounting or securing system. This code means the sensor is not properly secured to the vehicle structure, has been dislodged, or the mounting bracket has failed. The side crash sensor is a ...
The most common cause of B2440 (Passenger Sid, Side crash sensor mount fault) is: Physical damage to sensor mounting bracket or sensor dislodged from mount due to previous collision, improper installation, or corrosion
Typical repair costs for B2440 range from $150 to $650, 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 side airbags from deploying correctly in a lateral collision. The vehicle should not be driven until repaired as occupant protection is compromised. Repair should be completed immediately.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2440 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Body
System
Supplemental Restraint System (SRS) / Airbag System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
