OBD-II trouble code
B0071: First Row Center Seatbelt Pretensioner Deployment Control (Subfault)
The airbag/SRS control module detected a fault in the first-row center seat belt pretensioner deployment circuit — the pyrotechnic device that tightens the middle front belt in a crash. The pretensioner may not fire when needed, 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
- $150 – $900
- DIY difficulty
- Shop recommended
What does B0071 mean?
B0071 is a body (B) code stored by the airbag/SRS control module — often called the Restraints Control Module (RCM) or SDM (Sensing and Diagnostic Module). Its SAE-generic definition is 'First Row Center Seatbelt Pretensioner Deployment Control,' referring to the firing (deployment) circuit for the pretensioner on the center (middle) seating position of the front row. A pretensioner is a small pyrotechnic device that instantly retracts and tightens the seat belt at the start of a crash. Because a front-center pretensioner only exists on vehicles with a front bench seat or three-across first row, this code may not apply to a vehicle with two front bucket seats — confirm the definition against your make's service data.
This is a deployment-control fault, not a sensor fault: the module continuously checks that it can fire the center pretensioner and has found the circuit out of range — an open, a short, or resistance outside the tight window these firing loops require. Common causes are a corroded or backed-out connector at the belt retractor or buckle, wiring damaged where the harness flexes with seat use, a failed pretensioner (or one already deployed in a past crash and not replaced), or an internal module fault. A symptom byte appended to the code points to the specific condition. When the module can't verify the firing loop it disables that pretensioner and lights the airbag warning lamp.
This is a supplemental restraint fault, not a driveability fault: the car drives normally, but the center-position belt pretensioner may not deploy in a crash, reducing the protection the restraint system is designed to provide. Pretensioner firing circuits contain pyrotechnic charges that can deploy unexpectedly if mishandled, so B0071 should only be diagnosed and repaired by a qualified technician who can safely disable the SRS first.
Common causes
- Corroded, backed-out, or loose connector at the center belt retractor or buckle pretensioner
- Damaged wiring where the seat/belt harness flexes with seat use
- Failed center seat belt pretensioner
- Pretensioner already deployed in a past event and not replaced
- Moisture intrusion at the floor/under-seat connector
- Faulty airbag/SRS control module
Symptoms
- Airbag / SRS warning light on
- Stored B0071 fault (often with a symptom byte) in the restraints module
- Center-position seat belt pretensioner disabled and will not deploy in a crash
- No effect on engine or driving performance
- Possible additional SRS codes stored alongside it
Diagnostic steps
- 1.Use a scan tool that can access the airbag/SRS module and record B0071 with its full symptom byte and any companion restraint codes.
- 2.Confirm the vehicle actually has a first-row center seating position with a pretensioner, and confirm the exact definition for the make and model.
- 3.Confirm whether the vehicle has been in a prior crash that could have deployed the pretensioner.
- 4.With the SRS safely disabled per the service procedure, inspect the connector at the center belt retractor and buckle and the floor harness for corrosion, moisture, or backed-out terminals.
- 5.Measure the pretensioner firing loop resistance against specification to separate a wiring fault from a failed or already-deployed device.
- 6.If both B0071 and a companion pretensioner code (such as B0070) are stored, focus on a shared connector, power, or ground rather than two independent failures.
- 7.Replace a failed or deployed pretensioner or repair the wiring/connector, then clear codes and confirm the SRS light stays off.
Repair cost
$150 – $900
A connector or wiring repair can be modest, while a replacement center seat belt pretensioner/retractor assembly commonly runs $200-$800 including diagnosis, and a deployed pretensioner after a crash must be replaced, not reset. SRS diagnostic time typically runs $100-$200. Because pretensioners are pyrotechnic devices, this is professional SRS work.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with airbag control module (sdm) replacement / reset 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.