B004A: Third Row Right Frontal Stage 2 Deployment Control

What it means

The restraint control module monitors the stage 2 deployment circuit for the third-row right frontal airbag. It sets this code when it detects an electrical fault in that circuit, such as an open, short, or resistance outside its expected range.

At a glance

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

How it works

The restraint control module monitors stage 2 of the third-row right frontal airbag's deployment circuit. B004A sets when this stage 2 circuit has an electrical fault, such as an open, short, or resistance outside the expected range.

Common causes

Most likely first.

1. Open or high resistance in the stage 2 inflator circuit
2. Shorted or damaged wiring
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. Read B004A's subfault and event data with an SRS-capable scan tool, and note whether the third-row right frontal stage 2 fault is current or intermittent.
2. Power down the vehicle as directed by the manufacturer and inspect the stage 2 wiring and connectors at the third-row right frontal airbag for damage, looseness, corrosion, or prior repairs.
3. Use the manufacturer's wiring diagram and SRS-safe method to check the stage 2 circuit for an open or short.
4. Check stage 2 circuit resistance and terminal contact using the specified procedure and specification; avoid probing the inflator unless the procedure expressly permits it.
5. If the wiring and connections pass, follow the manufacturer's diagnosis to determine whether the airbag module or restraint control module is faulty.

Common fixes

• Repair damaged wiring in the third-row right frontal stage 2 circuit.
• Reseat or repair a loose or corroded stage 2 connector under the manufacturer's SRS procedure.
• Replace the airbag module if testing confirms a stage 2 deployment-control fault within it.
• Repair or replace the restraint control module if the circuit and airbag module pass and module testing confirms the fault.

Can I keep driving?

The third-row right frontal airbag's stage 2 may be unavailable in a crash, so have the SRS fault diagnosed promptly and avoid that seating position until repaired. Do not handle airbag wiring outside the manufacturer's safety procedure.