B001A is GM's code for the driver seat belt anchor pretensioner deployment loop. That is the pretensioner at the anchor end of the driver belt down by the seat, not the one in the retractor up in the pillar. The module measures the circuit with the key on and sets B001A when the reading falls outside GM's window.
Plenty of GM vehicles carry two pretensioners on the driver belt: one in the retractor that pulls webbing back into the reel, one at the anchor end that pulls the anchor down and takes slack out of the lap portion. Each has its own initiator, its own pair of wires to the SDM, and its own code. B001A is the anchor unit, B0015 the retractor unit on the same belt.
GM publishes the thresholds behind the symptom bytes here, which makes the two digits after the number worth writing down. Byte 01 sets when the pretensioner control circuit is shorted to voltage for two seconds. 02 is the same duration shorted to ground, 04 is an open circuit, 0D is loop resistance above 4.2 ohms, and 0E is resistance below 1.4 ohms. The module only runs the test with ignition voltage between 9 and 16 volts, so a weak battery or a charging fault can keep it from testing at all.
Once it sets, the SDM has the cluster light the AIR BAG indicator. A history code clears itself after 100 fault free ignition cycles, so an intermittent connection can leave a code in memory long after the light went out.
Circuit. The module is reporting a live measurement on two wires, so the repair sits in the connector, the harness, or the pretensioner. One overlap comes up often. A driver belt that fired in a collision leaves the loop open, so B001A with symptom byte 04 usually shows up next to a locked deployment record, and that vehicle has two jobs waiting on it: the fired belt hardware, and the crash data stored in the SDM.
No. Clearing memory does nothing to a circuit that measures out of range, and the module tests the loop again at the next key on. Repair the circuit first. If the anchor pretensioner fired, our seat belt repair service rebuilds the fired unit and returns the belt working and unlocked. Once the hardware is right and the module is still holding a deployment record, an airbag module reset clears the crash data out of your original SDM.
B001A comes from GM's later restraint numbering and reads the same on Buick, Chevrolet, GMC, and Cadillac vehicles built on it. GM's chart groups it with B0015 for the driver retractor pretensioner, B001B for the passenger anchor pretensioner, and B0022 for the passenger retractor pretensioner, so those four numbers tell you which belt and which end of it. Other manufacturers do not use B001A for a belt circuit, so confirm the code came out of a GM module.
Disconnect the battery and let the system sit a few minutes before unplugging anything under the seat, then look at the pretensioner connector. Check that the CPA retainer is pushed home, because a retainer that is not seated lets the shorting bar inside the connector bridge both control circuits,, which reads back as a short to ground or a low resistance byte. Check the terminals for the dull grey film fretting leaves, and run the harness through the full range of seat travel looking for a stretched or pinched section.
If the pretensioner already fired, that is the repair, and a rebuilt assembly or a replacement seat belt pretensioner puts the loop back in range. When the same reading turns up on the passenger side, B001B is the number to follow. If the part is not listed in the store, send the year, model, and VIN through request a part.
Related codes: B0015, B001B, B0022
Keep reading:
Code scope: Buick, Chevrolet, GMC, Cadillac. The same number can mean something different on another manufacturer, so match the code to your make before you act on it.
A reset clears stored crash data. A replacement part fixes a hardware fault. We have read these codes since the nineties and will tell you which one you are looking at.
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Buick parts and codes · Do not see it listed? Request a part or call 501-988-0611.