OBD-II trouble code
B0093: Left Side Restraints Sensor 3 (Subfault)
The airbag/SRS control module detected a fault in the left-side restraints sensor 3 circuit. Side-impact protection on that side may not deploy as designed, so this needs prompt professional attention.
Quick facts
- System
- Body
- Category
- Airbag / SRS Restraints
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $700
- DIY difficulty
- Shop recommended
What does B0093 mean?
B0093 is a body (B) code stored by the airbag control module. Its SAE-generic definition is 'Left Side Restraints Sensor 3,' referring to a third left-side satellite impact sensor on vehicles that use several. These sensors detect a side collision and report it to the module so it can fire the side and curtain airbags and seat-belt pretensioners on that side. B0091 covers Sensor 1, B0092 covers Sensor 2, and B0093 covers Sensor 3 — additional sensors let the module localize where along the side the impact occurred. As with all B-codes, confirm the exact application against your make's service data.
The module sets B0093 when that sensor's circuit reads out of range — open, shorted, or with resistance outside the narrow band these safety circuits demand — or when the sensor stops reporting valid data. Because a side-impact sensor is mounted low in a door, B- or C-pillar, rocker, or seat frame, its wiring and connector are exposed to moisture, road spray, and repeated flexing, which is why connector corrosion and harness damage are among the most common causes. When several left-side sensor codes appear together, a shared power, ground, or connector is a more likely explanation than several failed sensors.
This is a supplemental restraint fault, not a driveability fault: the vehicle drives normally, but the side-impact protection on the affected side may not work as designed in a crash, and airbag circuits carry a small risk of unintended deployment when mishandled. SRS diagnosis and repair should be performed by a qualified technician who can safely disable the system, and the fault should not be left unrepaired.
Common causes
- Corroded, wet, or loose connector at the side-impact sensor
- Damaged wiring in the door, rocker, pillar, or seat harness (flex fatigue or water intrusion)
- Failed left side-impact restraint sensor
- Shared power, ground, or connector fault when multiple side-sensor codes set together
- Prior collision or door/rocker repair that disturbed the sensor or wiring
- Faulty airbag/SRS control module
Symptoms
- Airbag / SRS warning light on
- Stored B0093 fault in the restraints module
- No effect on engine or driving performance
- Often accompanied by other left-side restraint-sensor codes (B0091/B0092)
Diagnostic steps
- 1.Use a scan tool that can access the airbag/SRS module and record B0093 and any companion restraint codes.
- 2.Confirm the exact sensor location for the specific make and model, since side restraint-sensor numbering and placement differ across manufacturers.
- 3.If B0091, B0092, and B0093 all set together, check the shared left-side power, ground, and connector first before condemning any single sensor.
- 4.With the system safely disabled per service procedure, inspect the sensor connector and harness for corrosion, moisture, or damage.
- 5.Check areas exposed to water and flexing — the lower door, rocker, pillar base, or seat frame.
- 6.Measure the sensor circuit's resistance against specification to separate a wiring fault from a failed sensor.
- 7.Repair wiring/connector faults or replace the indicated sensor, then clear codes and confirm the SRS light stays off.
Repair cost
$100 – $700
A connector or wiring repair can be modest, while replacing a side-impact restraint sensor commonly runs $200-$600 including diagnosis. When several side-sensor codes set together, the fix is often a single shared connector or ground rather than multiple sensors. SRS work should be done by a qualified technician, so plan for professional diagnostic time.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with airbag / srs crash sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.