OBD-II trouble code
B0061: Passenger Seatbelt Tension Sensor (Subfault)
The airbag/SRS control module detected a fault in the passenger seat belt tension sensor circuit — the sensor that measures how tightly the passenger belt is pulled, used to help classify the passenger and tailor airbag deployment. 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 – $600
- DIY difficulty
- Shop recommended
What does B0061 mean?
B0061 is a body (B) code stored by the airbag/SRS control module — often called the Restraints Control Module (RCM) or, where occupant sensing is a separate unit, the Occupant Classification System Module (OCSM). Its SAE-generic definition is 'Passenger Seatbelt Tension Sensor,' referring to a sensor that measures the tension in the front passenger's seat belt. Unlike a simple buckle switch, a tension sensor reads how tightly the belt is pulled. That matters because a child seat secured with a cinched-down belt looks very different from a belted adult, so the system uses belt tension together with the seat weight/occupant-classification data to decide whether the passenger should be treated as an adult, a small occupant, or a child seat — and therefore whether and how forcefully the passenger airbag should deploy.
The module sets B0061 when the tension sensor reports invalid data or its circuit falls out of specification — an open or short in the sensor wiring, a corroded or backed-out connector under the passenger seat, a failed sensor, or a fault in the classification module. These circuits are monitored against a tight resistance window, so even a marginal connection can trigger the code. A symptom byte appended to the code narrows down the exact condition. Because the sensor and its harness live under the passenger seat and flex with seat travel, the most common trouble spot is the under-seat connector; spilled liquids, floor moisture, and aftermarket seat covers or heaters are frequent contributors, and many systems require a zero/recalibration procedure after any seat or sensor service.
This is a supplemental restraint fault, not a driveability fault: the car drives normally, but the airbag warning light is on and the passenger occupant-classification system may not perform as intended — which can leave the passenger airbag suppressed or mis-tailored. Airbag circuits carry a small risk of unintended deployment when mishandled, so SRS diagnosis, repair, and recalibration should be left to a qualified technician.
Common causes
- Corroded, backed-out, or loose connector under the passenger seat
- Damaged wiring in the seat harness where it flexes with seat travel
- Failed passenger seat belt tension sensor
- Moisture intrusion or spilled liquid at the under-seat connector
- System out of calibration or never zeroed after seat/sensor service
- Faulty occupant classification module or airbag/SRS control module
Symptoms
- Airbag / SRS warning light on
- Passenger airbag ON/OFF indicator behaving incorrectly or stuck OFF
- Persistent seat-belt reminder chime for the passenger position
- Stored B0061 fault (often with a symptom byte) in the restraints/occupant module
- No effect on engine or driving performance
Diagnostic steps
- 1.Use a scan tool that can access the airbag/SRS or occupant-classification module and record B0061 with its full symptom byte and any companion codes.
- 2.Confirm no aftermarket seat cover, seat heater, or heavy item is interfering with the passenger seat, and remove anything unusual before testing.
- 3.With the SRS safely disabled per the service procedure, inspect the under-seat connector and seat harness for corrosion, moisture, or backed-out terminals.
- 4.Measure the tension sensor circuit against specification (many systems expect a specific resistance value) to separate a wiring/connector fault from a failed sensor.
- 5.If a companion passenger seat belt sensor or occupant-classification code is present, treat the passenger seat restraint circuits as a set and check for a shared connector, power, or ground.
- 6.If the seat, sensor, or module was recently serviced, run the make-specific zero/recalibration procedure, which many systems require.
- 7.Repair the wiring/connector or replace the sensor, recalibrate, then clear codes and confirm the SRS light stays off.
Repair cost
$100 – $600
A connector repair or a recalibration can be inexpensive, while a failed passenger seat belt tension sensor is costlier and often needs occupant-classification recalibration after replacement. SRS diagnostic time typically runs $100-$200; sensor replacement with the required calibration commonly falls in the $200-$600 range. SRS work should be done by a qualified technician.
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.