B0070: Driver Seat Belt Pretensioner A Deployment Control

Usually crash data

What B0070 means

A seat belt pretensioner is a one-time pyrotechnic device built into the buckle or retractor. When the module senses a crash, it fires the pretensioner to pull the slack out of the belt a fraction of a second before the airbag. B0070 is the deployment control code for the driver pretensioner, the A circuit.

After a deployment, B0070 is the module's record that the driver pretensioner fired. Two things are true at once: the module is holding stored data, and the pretensioner hardware is spent. A fired pretensioner cannot fire again, so the belt has to be rebuilt or replaced before the system is whole. That is the seat belt side of the job, separate from clearing the module.

Common causes

• The driver pretensioner deployed in an accident, leaving stored crash data and a spent device
• An open or shorted pretensioner circuit, often a connector at the seat track or buckle
• Corroded pins after moisture got into the seat-belt harness
• A locked retractor or jammed belt after a deployment

Crash data or hardware fault?

If the pretensioner deployed, B0070 is stored crash data on the module side, and a spent device on the hardware side. The module reset clears the data, and the belt gets rebuilt so the pretensioner works again. If B0070 shows up with no deployment, it is more likely a circuit or connector fault in the pretensioner loop that needs repair. We sort out which by reading the code and the belt together.

Does our reset clear it?

On the module side, yes. Our airbag module reset clears the stored B0070 record. But the spent pretensioner is the other half of this code, and that is a separate fix. We also rebuild seat belts and pretensioners, so we can handle both ends in one stop. See our seat belt pretensioner repair.

Which makes throw it

B0070 is a generic body code, common on Ford, Lincoln, and Mercury, and seen across many other makes. Some manufacturers label it the driver pretensioner A loop, the wording most likely to appear on your scanner.

What to do next

Rebuild or replace the spent driver pretensioner and confirm the belt retracts and locks correctly, then mail us the module to clear the stored data. We can do both. Related codes: B0001 (driver frontal), B0051 (deployment commanded), and B1193 (crash data locked).