B001A: Center Frontal Stage 3 Deployment Control

What it means

Fault on the deployment circuit of the center frontal airbag, deployment stage 3 (highest severity). Used in dual or triple-stage front airbag systems for severe crash energy.

At a glance

• Usually lights the airbag (SRS) or body-system warning light

How it works

Some vehicles use a center frontal airbag with multiple inflator stages; stage 3 is the highest-output stage, intended for the most severe crash conditions. The restraint control module monitors its deployment loop and sets B001A when that loop has a fault such as an open or excessive resistance; confirm the precise condition from the accompanying SRS fault details.

Common causes

Most likely first.

1. Open or high resistance in stage 3 airbag inflator circuit
2. Damaged wiring or connector at the inflator or restraint control module
3. Loose or corroded connector
4. Fault in the restraint control module

Symptoms

• Warning light or symbol related to the affected system
• Comfort or safety function impaired

How to diagnose it

1. Use an SRS-capable scan tool to retrieve the restraint-module subfault and freeze-frame data, confirming that the fault is for center frontal stage 3.
2. Power down and disable the SRS exactly as the manufacturer specifies, then inspect the center frontal inflator connector and harness for looseness, corrosion, or damage.
3. Check the stage 3 wiring route to the restraint control module for chafing, pinching, or disconnected terminals that could cause an open or high-resistance connection.
4. Use the manufacturer’s approved SRS test method to evaluate the connector and circuit; do not directly resistance-test the inflator with a standard meter.
5. If the loop checks pass, continue with the manufacturer’s diagnostic procedure for the center frontal airbag module and restraint control module.

Common fixes

• Correct a loose or corroded stage 3 connector using the approved SRS procedure.
• Repair damaged or pinched wiring in the center frontal stage 3 circuit.
• Replace a faulty center frontal airbag module if the prescribed tests isolate the fault there.
• Replace or reprogram the restraint control module only when manufacturer diagnostics confirm a module fault.

Can I keep driving?

Treat the SRS warning as a safety fault: the center frontal airbag’s highest-output stage may be unavailable in a severe crash. Limit driving to what is necessary to get the fault diagnosed, and do not disturb its wiring or connectors.