B1020 on 2007-2012 Nissan Altima — Airbag/SRS Deployment Loop Fault (Manufacturer-Specific)
1 vehicles · 1 makes · $250-$1,800 repair
How to diagnose and fix B1020: most-reported vehicles
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Nissan Altima · 2007–2012
Multiple 2007-2012 Altima owners report the air bag warning light flashing and the passenger air bag status behaving incorrectly due to faults in the occupant classification system (OCS) or related seat sensor components. This can disable the passenger frontal air bag when it should be enabled, or trigger a persistent SRS warning light. Nissan issued service information and warranty extensions on some related OCS concerns because the issue was common enough to generate many complaints and dealer repairs.
Common Symptoms
- air bag light flashing
- passenger air bag off light stays on with adult seated
- SRS warning light illuminated
- intermittent passenger air bag operation
- warning returns after battery disconnect
How to Fix
Diagnosis requires a capable scan tool that can read SRS and OCS data, not just generic OBD-II codes. Technicians typically inspect seat harness connections, zero-point calibration, seat cushion sensor mat operation, and the occupant detection control unit. Repairs may involve OCS recalibration, harness repair, or replacement of the passenger seat cushion/sensor assembly followed by SRS initialization.
Sources for this issue (1)
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B1020 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does B1020 mean?
B1020 stands for "Airbag/SRS Deployment Loop Fault (Manufacturer-Specific)." B1020 is a manufacturer-specific body code; on GM-family vehicles it falls within the airbag (SIR/SRS) deployment-loop fault range, indicating the airbag module detected an electrical problem (such as a short or out-of-range resistance) in a deployment loop circuit. Because the exact loop and fault type vary by manufacturer and model, a make-specific scan tool and service manual are needed to confirm the precise circuit. As an SRS fault, the airbag warning light typically illuminates and proper airbag deployment may be affected, so it warrants prompt diagnosis.
What are the most common causes of B1020?
The most common causes of B1020 are: Open, shorted, or high-resistance wiring in an airbag deployment loop, Corroded, wet, or loose connector in the SRS circuit, Faulty clockspring (for steering-wheel-mounted airbag circuits), Faulty airbag inflator/module, Faulty airbag (SRS/SDM) control module, Harness damage from prior repair or accessory work, Poor ground connection. The specific cause varies by vehicle.
How much does it cost to fix B1020?
Repair costs for B1020 range from $250 to $1,800, depending on the vehicle and root cause.
Which vehicles are affected by B1020?
Au7o has documented B1020 across 1 vehicle models from 1 manufacturers: Nissan.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.