B1B04: Driver Airbag Squib 2, Low

Circuit fault

What B1B04 means

Driver airbags on these vehicles deploy in stages, and squib 2 is the circuit that fires the second one in a harder impact. The occupant restraint controller measures that loop with a small test current and expects a resistance inside a narrow band. Anything below the band means current is finding a shortcut, and B1B04 gets stored.

Everything between the controller and the inflator counts as part of the loop. The dash harness, the clockspring in the steering column, the connector at the airbag, and the second stage bridge wire inside the inflator all share responsibility for the reading. Testing each section separately is what keeps a clockspring job from turning into an unnecessary airbag replacement.

Common causes

• A clockspring shorted internally on the squib 2 circuit
• The driver airbag connector damaged or not fully latched
• Column harness pinched during steering wheel or column service
• An inflator second stage that has shorted inside the airbag
• A chafed wire in the dash harness touching another conductor

Crash data or hardware fault?

B1B04 tracks a live resistance, which is what puts it in the circuit family. It clears when the loop measures normally again. Crash data is written only after a deployment, locks itself into module memory, and cannot be erased with a scan tool, so the two categories are handled very differently.

Does our reset clear it?

Clearing or resetting the module does not repair a low squib 2 reading. The controller measures the loop again at the next key on and sets B1B04 right back. Fix the clockspring, the connector, or the airbag first. Our mail-in reset earns its keep on modules that hold deployment records, not on live wiring faults.

Which makes throw it

Chrysler, Dodge, and Jeep all list B1B04 with the same meaning on the driver airbag squib 2 circuit.

What to do next

Check whether B1B00 or another squib 1 code is stored at the same time, because both circuits failing together usually means the clockspring rather than the airbag. With the battery off and the system bled down, remove the airbag and measure each loop at the clockspring pigtail and again at the controller. A low reading only at the airbag means the inflator is the part to replace. Related codes: B1B02, B1B08, 31-1X.