Loose, corroded or damaged connector on the deployment circuit, often under or near the rear seat; Damaged or chafed wiring, open circuit or short, for example from seat movement or trapped harness; Faulty second row right restraint device or its initiator (resistance out of range); Poor connection at the seat or belt connector after the seat was removed, moved or repaired; Previous collision or repair damage to the restraint harness or components; Internal fault in the restraint control unit deployment driver; Outdated or faulty control unit calibration, only where the manufacturer lists it as a known cause for this model.

B003A

Second Row Right Frontal Stage 2 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
3A: FaultThe specific fault in that area

What it means

B003A is the generic SAE J2012 code for a fault in the Second Row Right Frontal Stage 2 Deployment Control circuit. The restraint control unit runs self-tests on its deployment circuits. It set this code because it saw a reading outside the expected range for this circuit, such as an open circuit, a short, or a resistance error. Which device sits on this circuit (a rear-seat airbag, a belt pretensioner or another restraint) depends on the model, so check the wiring diagram for the vehicle.

Symptoms

Airbag or SRS warning light on the dashboard
Warning light stays on after starting and does not go out
Possible message about a restraint system fault
The right rear restraint device may not deploy in a crash
Fault may come and go if a connector or wiring is marginal
Failed or advisory result at inspection if the SRS light is on

Possible causes

Loose, corroded or damaged connector on the deployment circuit, often under or near the rear seatlikely
Damaged or chafed wiring, open circuit or short, for example from seat movement or trapped harnesslikely
Faulty second row right restraint device or its initiator (resistance out of range)possible
Poor connection at the seat or belt connector after the seat was removed, moved or repairedpossible
Previous collision or repair damage to the restraint harness or componentspossible
Internal fault in the restraint control unit deployment driverrare
Outdated or faulty control unit calibration, only where the manufacturer lists it as a known cause for this modelrare

How to diagnose

Read all stored codes and freeze frame data, and note whether B003A is current, intermittent or history, and whether other restraint codes are present
Ask about any recent seat removal, trim work, accident repair or seat cover fitting near the second row right position
Visually inspect the rear seat area, harness routing and connectors for damage, pinching, water or corrosion, without disturbing any restraint device
Follow the manufacturer's procedure to make the system safe first, including disconnecting the battery and waiting the specified time, before unplugging any restraint connector
Check the connector for bent, pushed-back or corroded terminals and for locking or shorting clips that must be correctly fitted
Never probe or measure resistance directly across an initiator or squib, and only test the circuit using the procedure and limits in the manufacturer's data
Check the wiring continuity and insulation between the control unit and the device, using the vehicle wiring diagram
Clear the code and recheck, and if it returns at once, suspect the device or the control unit once the wiring is confirmed good

How to fix

Clean, repair or replace the damaged connector or terminals on the circuit
Repair or replace the damaged section of the harness, using the manufacturer's approved wiring repair method
Replace the faulty second row right restraint device if the circuit and connector are proven good
Refit and secure the harness and connectors correctly after seat or trim work
Replace or reprogram the restraint control unit only if the manufacturer's tests confirm it is faulty or a calibration update is specified for this model

Can I keep driving?

High severity

The car will usually still drive, but the right rear restraint may not work in a crash, so limit use, especially with passengers in that seat. Get it inspected promptly by someone qualified to work on airbag systems.

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