Damaged or chafed wiring in the third row right seat or pillar area; Corroded or loose electrical connector at the third row right airbag module; Faulty third row right frontal airbag stage 2 inflator (open or shorted squib); Water intrusion or physical damage to the airbag module or wiring harness; Internal fault in the restraint control module (RCM); Aftermarket accessories or improper previous repairs interfering with the circuit

DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B004A

B004AThird Row Right Frontal Stage 2 Deployment Control

Q: What does code B004A mean?

Third Row Right Frontal Stage 2 Deployment Control. B004A indicates that the restraint control module (RCM) has detected a fault in the deployment circuit for the third row right frontal airbag stage 2. This circuit is responsible for firing the second stage of the inflator in a severe collision, and the module monitors its resistance and continuity to ensure it is ready to deploy.

B004A indicates that the restraint control module (RCM) has detected a fault in the deployment circuit for the third row right frontal airbag stage 2. This circuit is responsible for firing the second stage of the inflator in a severe collision, and the module monitors its resistance and continuity to ensure it is ready to deploy.

SystemBody

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

Airbag warning light illuminated on the instrument cluster
Often no symptoms besides the warning light
The airbag system may be disabled, preventing deployment in a crash
In some vehicles, a message on the driver information center indicating a service restraint system
Intermittent warning light if the fault is caused by a loose connection

Common causes, most likely first

Damaged or chafed wiring in the third row right seat or pillar area
Corroded or loose electrical connector at the third row right airbag module
Faulty third row right frontal airbag stage 2 inflator (open or shorted squib)
Water intrusion or physical damage to the airbag module or wiring harness
Internal fault in the restraint control module (RCM)
Aftermarket accessories or improper previous repairs interfering with the circuit

How to diagnose and fix it

Inspect the third row right seat area for visible wiring damage, pinched harnesses, or corrosion
Disconnect the battery and wait for the system to discharge, then check the connector at the airbag module for tightness and cleanliness
Measure the resistance of the stage 2 squib circuit with a digital multimeter and compare to manufacturer specifications
Check for continuity and shorts to ground or power on the wiring between the RCM and the airbag module
If wiring and connectors are good, substitute a known-good airbag module only if the manufacturer allows, to see if the code changes
Repair or replace damaged wiring or connectors as needed, following service procedures
Clear the code and verify the repair with a scan tool; if the code persists, diagnose the RCM or seek dealer-level programming

Before you replace the airbag module

A common mistake is replacing the airbag module when the real problem is a corroded connector under the third row seat, which is often exposed to spills or moisture.
The code can be set by a low battery or charging system issue that causes a momentary voltage drop, so always check battery health and connections first.
After any airbag circuit repair, the system must be cleared with a scan tool; simply disconnecting the battery will not turn off the light.
Seat removal or installation for other repairs can pinch the airbag wiring, leading to this code, so inspect carefully after any interior work.
This code does not always mean the airbag is defective; it can also be triggered by a faulty RCM or a communication error within the restraint system.

Can I keep driving with B004A?

Because this fault can prevent the third row right frontal airbag from deploying correctly in a crash, have it diagnosed and repaired promptly. Avoid rough roads or any activity that could further damage the wiring, and do not attempt to repair the airbag system yourself without proper training.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.