B004A

What it means

B004A is the SAE generic code for a fault in the deployment control circuit for the third row right, stage 2 frontal restraint device. The restraint control unit runs self-tests on its deployment loops, and it set this code because it saw a fault in that circuit, such as an open circuit, short, or resistance outside the expected range. Which device sits in this position, and how it is wired, depends on the model.

Symptoms

• Airbag or SRS warning light on the dashboard
• Light stays on after start-up and does not clear
• Passenger or third-row seat restraint status shown as faulty on some models
• Other SRS codes stored alongside it
• Failed inspection or pre-sale check because of the SRS warning

Possible causes

• Loose, corroded or damaged connector in the third row right restraint circuit, often under or beside the seatlikely
• Damaged wiring, for example chafed or pinched by a folding seat, trim or cargo area movementlikely
• Connector disturbed after seat removal, reconfiguration or interior workpossible
• Faulty third row right restraint device or its initiatorpossible
• Water ingress or corrosion in the rear floor or side trim wiring after a leakpossible
• Fault inside the restraint control unitrare
• Previous crash damage or incorrect repair of the restraint systemrare

How to diagnose

1. Read all stored codes with an SRS-capable scan tool and note whether other restraint or seat codes are present.
2. Check the code status and any freeze frame or event data to see if the fault is current or stored.
3. Ask about recent seat removal, interior work, water leaks or accident repairs.
4. Look for obvious damage, water or corrosion on the third row right seat, trim and floor wiring, without disconnecting any restraint connectors yet.
5. Disconnect the battery and wait for the time stated by the manufacturer before touching any restraint connector, then check the connectors for security, bent pins and corrosion.
6. Check the wiring along the route for chafing, pinching or previous repairs, using the manufacturer's wiring diagram for your model.
7. Do not test restraint devices or circuits with a test lamp or standard meter. Use only the manufacturer-approved procedure and live data on the scan tool.
8. Clear the code after repair and confirm it does not return after the system self-test.

How to fix

• Reseat, clean or replace the faulty connector, using the correct locking clips.
• Repair or replace damaged wiring with the approved method. Do not make ordinary splices in restraint wiring unless the manufacturer allows it.
• Refit and route the wiring correctly after seat or trim work.
• Replace the faulty restraint device or component if testing confirms it, following manufacturer procedures.
• Dry out and repair any water damage, and replace corroded parts.
• Replace or repair the restraint control unit only if the manufacturer's diagnostics confirm it is at fault.

Can I keep driving?

Nearby codes

• B0049GenericThird Row Right Frontal Stage 1 Deployment Control
• B004BGenericThird Row Right Frontal Stage 3 Deployment Control