B1391 Diagnostic Trouble Code: Manufacturer Specific (OEM) Body & Safety Module DTC B1391
Detailed technical diagnosis, symptoms, common causes, inspection procedures, and estimated repair costs.
⚠️ Can I Drive With Code B1391?
Safe to drive to a repair shop or home, but arrange inspection soon to maintain optimal efficiency and pass emissions.
🚨 Symptoms of Code B1391
- Check Engine Light (CEL / MIL) illuminated on dashboard
- Vehicle stored diagnostic trouble code in PCM memory
- Possible reduction in engine performance or fuel economy
- System operating under fail-safe or default backup parameters
🔍 Most Common Causes for Code B1391
- Faulty or degraded sensor related to body electronics (airbags / srs / climate / lighting)
- Damaged, corroded, or loose wiring harness connector
- Intermittent short circuit or open circuit to ground / reference voltage
- Software update required or internal controller calibration fault
🛠️ Step-by-Step Diagnostic & Multimeter Inspection Procedure
- Connect an OBD-II / EOBD scan tool and verify active and pending B1391 codes
- Inspect wiring harness and connector pins for corrosion, bent pins, or thermal damage
- Check circuit power and ground with a digital multimeter (DVOM)
- Review manufacturer Technical Service Bulletins (TSBs) for known vehicle issues
Common Diagnostic Mistake to Avoid: Replacing the sensor before verifying wiring harness continuity, supply voltage, and ground connection.
Frequently Asked Questions — B1391 DTC
What does OBD-II code B1391 mean?
Code B1391 stands for 'Manufacturer Specific (OEM) Body & Safety Module DTC B1391'. It indicates an issue detected by the powertrain or control module within the Body Electronics (Airbags / SRS / Climate / Lighting).
Can I continue driving with code B1391 active?
Safe to drive to a repair shop or home, but arrange inspection soon to maintain optimal efficiency and pass emissions.
What are the most common causes of code B1391?
The most frequent root causes include: Faulty or degraded sensor related to body electronics (airbags / srs / climate / lighting), Damaged, corroded, or loose wiring harness connector, Intermittent short circuit or open circuit to ground / reference voltage.
How much does it typically cost to fix code B1391?
The average repair cost for code B1391 ranges from $65 – $420, depending on whether it requires a basic sensor replacement, wiring repair, or major mechanical component.