B1905: Crash Sensor #2 Short to Battery
The B1905 code indicates that the Restraint Control Module (RCM) has detected a short circuit to battery positive voltage in the power or signal circuit of the #2 crash sensor. This sensor, typically located on the side or front of the vehicle, measures deceleration for airbag deployment. A short to 12V corrupts the sensor reading, disabling the Supplemental Restraint System (SRS) and turning on the airbag warning light.
1. Commonly Affected Makes
2. Most Common Causes
- Short to battery positive in the #2 crash sensor wiring (e.g., chafing against a power harness)
- Internally shorted #2 crash sensor (satellite/side sensor)
- Damaged sensor connector with bent pins or corrosion bridging terminals
- Faulty RCM (airbag module) with an internal shorted driver circuit
3. Symptoms You Will Notice
- Airbag warning light illuminated on the dashboard
- SRS system disabled (airbags may not deploy in a crash)
4. Step-by-Step Diagnosis
Scan the RCM for B1905 and any related codes
Visually inspect the #2 crash sensor connector and wiring for damage, corrosion, or shorts to power
Disconnect the sensor and measure resistance between signal/power pins and ground; check for continuity to battery positive
If wiring is okay, replace the #2 crash sensor and clear codes
If code returns, suspect a faulty RCM and perform further module diagnostics
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe. The SRS system is disabled, meaning airbags may not deploy in a collision, increasing injury risk. Have the vehicle repaired immediately.
How much does it cost to fix?▼
Repair costs typically range from $150 to $500, depending on whether the issue is wiring repair ($150-$250) or sensor replacement ($200-$500). RCM replacement can exceed $800.