Passenger Airbag Circuit Short to Ground
The B1938 code indicates a short-to-ground fault in the passenger airbag circuit. This code is set when the Restraints Control Module (RCM) detects abnormally low resistance in the passenger airbag circuit, meaning the circuit is making direct contact with chassis ground. This condition prevents the airbag system from deploying properly in a collision, posing a serious safety risk.
1. Commonly Affected Makes
2. Most Common Causes
- Damaged or chafed passenger airbag wiring shorting to ground
- Loose, corroded, or bent pins in the airbag harness connector
- Faulty passenger airbag module (internal short)
- Defective Restraints Control Module (RCM)
3. Symptoms You Will Notice
- Airbag warning light illuminated on the dashboard
- Supplemental Restraint System (SRS) fault message displayed
4. Step-by-Step Diagnosis
Scan the vehicle for all stored codes and note freeze frame data.
Visually inspect the passenger airbag wiring and connector for damage, corrosion, or loose pins.
Measure resistance between the airbag circuit wires and ground; a reading near zero confirms a short to ground.
If wiring is intact, test the passenger airbag module resistance per manufacturer specs.
If all else checks out, suspect a faulty RCM and perform further diagnostics or replacement.
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe to drive. The airbag system may not deploy in a crash, increasing the risk of injury. Have the vehicle towed to a repair shop.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on the cause. Wiring repairs are cheaper, while replacing the airbag module or RCM can be more expensive.