B1912: Air Bag Diagnostic Monitor Ground Circuit Short To Ground

What does B1912 mean?

B1912 is a diagnostic trouble code indicating "Air Bag Diagnostic Monitor Ground Circuit Short To Ground". The ECU is detecting a voltage reading that is below the expected range in the restraint system circuit. This typically points to a wiring short, a faulty sensor, or a grounding issue.

Symptoms you may notice

• Check engine light (MIL) illuminated on dashboard
• Intermittent warning lights
• Erratic gauge readings

Common causes

• Damaged or corroded wiring harness
• Loose or disconnected electrical connector
• Failed restraint system sensor or actuator
• Blown fuse in the related circuit
• Poor ground connection

What should you do?

This code sits in the occupant restraint system. The airbags or pretensioners may not fire in a crash, and on some faults they can fire when they should not. The car will usually drive and feel completely normal, which is exactly why this one gets ignored. Have it diagnosed before you carry passengers, and do not clear the code to make the light go away.