B1945: Crash Sensor #2 Ground Open
The B1945 code indicates an open circuit in the ground wire of the #2 crash sensor in the Supplemental Restraint System (SRS). The Restraints Control Module (RCM) has detected a break in electrical continuity to the sensor's ground reference, preventing the circuit from closing properly. Without a stable ground connection, the sensor cannot report acceleration or deceleration readings to the module during a crash event, compromising the system's ability to deploy airbags in the zone monitored by that sensor.
1. Commonly Affected Makes
2. Most Common Causes
- Open or broken ground circuit wiring for crash sensor #2
- Corroded, damaged, or loose pins in the sensor #2 electrical connector
- Faulty crash sensor #2 with internal open circuit
- Poor chassis ground connection or corroded ground point
- Mechanical damage to the SRS harness from a previous collision
3. Symptoms You Will Notice
- Airbag warning light illuminated on the dashboard
- SRS system may be disabled or inoperative
4. Step-by-Step Diagnosis
Scan the SRS module for B1945 and any related codes
Visually inspect the wiring and connector for crash sensor #2 for damage, corrosion, or loose pins
Check the ground circuit continuity from the sensor connector to chassis ground using a multimeter
If wiring is intact, test the sensor itself by measuring resistance across its terminals; compare to specifications
Inspect the chassis ground point for rust or poor contact; clean and tighten as needed
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe to drive. The SRS system may not deploy airbags in a collision, increasing the risk of injury. Have the vehicle repaired immediately.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the issue is a wiring repair, connector replacement, or sensor replacement.