Damaged, corroded or loose connector at the third row seat or trim airbag circuit; Wiring fault (chafing, open circuit, short to earth or voltage) in the deployment loop, often where harness passes through seat or trim pivot points; Faulty squib or airbag module with out-of-range resistance; Disturbed or damaged yellow SRS connector after seat removal, trim work or previous repair; Previous collision damage or incorrectly fitted replacement restraint component; Fault within the restraint control module itself.

B004B

Third Row Right Frontal Stage 3 Deployment Control.

Generic
Body
Generic code
High severity

How this code is built

B: SystemBody
0: Defined bySAE, the same on every car
0: AreaBody area 0
4B: FaultThe specific fault in that area

What it means

B004B is a body (restraint system) code. Under the generic definition it relates to the third row right frontal airbag, stage 3 deployment control circuit. The restraint control module has detected a fault in that deployment loop, such as an abnormal resistance, short or open circuit. Exact wording and the stage logic vary by manufacturer and model, and many makes do not use this code at all.

Symptoms

Airbag or SRS warning light on the dashboard
Restraint system fault message in the instrument cluster
Passenger airbag or third row airbag status indicator showing a fault
Car may fail an inspection or safety check due to the lit warning
Other SRS codes stored alongside it

Possible causes

Damaged, corroded or loose connector at the third row seat or trim airbag circuitlikely
Wiring fault (chafing, open circuit, short to earth or voltage) in the deployment loop, often where harness passes through seat or trim pivot pointslikely
Faulty squib or airbag module with out-of-range resistancepossible
Disturbed or damaged yellow SRS connector after seat removal, trim work or previous repairpossible
Previous collision damage or incorrectly fitted replacement restraint componentpossible
Fault within the restraint control module itselfrare

How to diagnose

Read all stored and pending SRS codes and record freeze frame or status data, noting whether the fault is current or history
Check the vehicle's service information to confirm which component this code refers to on this specific model, as third row layouts vary
Visually inspect the third row seat area, trim and harness routing for damage, pinching, water ingress or signs of past repair
Inspect and reseat the relevant SRS connectors, checking for bent pins, corrosion and intact locking or shorting clips, with the battery disconnected and the correct waiting time observed
Measure the deployment loop resistance only with the method and limits given by the manufacturer, never using an ordinary test light or unsuitable meter on airbag circuits
Check the wiring for continuity and shorts to earth or voltage, following the wiring diagram, with the module disconnected as instructed
Clear the code after repair and recheck that it does not return, then confirm the warning light goes out

How to fix

Repair or replace the damaged wiring section or connector as specified by the manufacturer, not by makeshift splicing
Clean or replace corroded or damaged SRS connectors and terminals
Replace the faulty airbag module or squib using the correct part and procedure
Correct any incorrectly fitted or disturbed components after previous work and refit the seat or trim properly
Replace the restraint control module if the fault is confirmed within it, with any required programming done to manufacturer procedure

Can I keep driving?

High severity

The airbag system may not deploy correctly in a crash, so this is a safety concern. The car can be driven carefully to a workshop, but have it inspected promptly and avoid carrying passengers in the affected seats if possible.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.