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B0049 — Third Row Right Frontal Stage 1 Deployment Control

Generic OBD-II · all makesBody

This code indicates that the airbag control module has detected an electrical fault—such as an open, short, or abnormal resistance—in the Stage 1 deployment circuit for the third-row right frontal airbag. Because the circuit is outside the expected parameters, the module disables that deployment path and stores the fault to warn the driver. The condition must be diagnosed to ensure proper supplemental restraint system operation.

Symptoms

What causes it — most likely first

1. Failed third-row right frontal Stage 1 inflator

The inflator's internal squib can develop an open circuit, short, or resistance shift from age or manufacturing variation, causing the ACM to flag the deployment loop as faulty.

2. Wiring fault in the deployment loop

The low-voltage deployment circuit can suffer from wire chafing, pinching, or internal breaks between the ACM and the inflator, creating an open or short condition.

3. Connector corrosion or poor terminal fit

Moisture, vibration, or thermal cycling can degrade the connector pins at the inflator pigtail or junction block, introducing high resistance or intermittent contact.

4. Incorrect or incompatible inflator installed

A replacement inflator with the wrong resistance specification or an improper connection can alter the deployment-loop signature enough to set this code.

5. Internal airbag control module fault

Rarely, the ACM's deployment-driver circuitry can falsely report a fault when the external loop is proven good; this should be the last possibility investigated.

How it's diagnosed

  1. Perform a visual inspection of the third-row right frontal airbag, harness, and connectors for damage, burns, or disconnection.
  2. Retrieve the full trouble code data from the ACM to identify whether the subfault is an open, short to ground, short to battery, or high resistance.
  3. Following proper de-energization and safety procedures, measure deployment-loop resistance or use an approved SRS load tool to isolate the inflator from the harness.
  4. Test the wiring harness for continuity between the ACM and inflator, and check for shorts to ground or voltage using a digital multimeter.
  5. If the inflator and wiring are verified good and no other deployment codes are present, consider testing or substituting the ACM only after all external causes are ruled out.

Code facts & related codes

SystemBody
StandardizationSAE generic — identical on every make

Frequently asked

Is it safe to drive with this code active?

The vehicle can be driven, but the third-row right frontal Stage 1 airbag may not deploy in an accident, so the fault should be repaired as soon as possible.

Can I just clear the code to turn off the airbag light?

No. The light will return because the underlying circuit fault remains; clearing the code without repair only temporarily extinguishes the warning.

Do I need to replace the airbag control module for this code?

Generally no. Most B0049 faults are caused by the inflator or its wiring. The ACM is rarely the culprit and should only be replaced after the deployment loop and connectors have been fully tested.

Could the airbag deploy randomly because of this fault?

No. This code reflects a circuit integrity failure that inhibits Stage 1 deployment rather than causing unintended deployment.