Airbags

B001A — Driver Seat Belt Anchor Pretensioner Deployment Loop Fault

Severity: medium Drive with care, to a shop

What B001A means

The airbag (SRS) control module tests the circuit that fires the driver's seat belt anchor pretensioner each time the ignition is turned on. B001A is set when the circuit resistance is out of range, due to an open, a short, or a poor connection. The pretensioner may not deploy in a crash.

Symptoms

  • Airbag/SRS warning light on or flashing
  • B001A stored, possibly with additional loop sub-codes
  • Driver pretensioner may not fire in a crash
  • Fault may come and go over bumps if a connector is loose

Possible causes

  1. Faulty pretensioner or its deployment circuit
  2. Damaged wiring harness or corroded connector under the seat
  3. Connector not fully seated or shorting bar misplaced
  4. Faulty SRS control module (SDM)
  5. Seat removal or repair work with connectors reinstalled incorrectly

How to diagnose

  1. Scan with a tool that reads SRS codes and note any sub-codes
  2. Disconnect the battery and wait the time the manufacturer specifies to avoid accidental deployment
  3. Inspect the pretensioner harness and connector for damage, moisture, corrosion, and chafing
  4. Confirm the connector is fully latched and the shorting bar is seated correctly
  5. Check the wiring for opens and shorts to ground or voltage using the factory diagram
  6. Never probe the pretensioner itself with a regular multimeter
  7. If wiring is good, test the circuit with a known-good component per the manufacturer procedure
  8. Clear the code and confirm it does not return

Common fixes

  • Secure the harness and clean the connectors, applying dielectric grease if the manufacturer allows
  • Repair the wiring or replace damaged terminals and connector
  • Replace the seat belt anchor pretensioner assembly
  • Replace or reprogram the SRS module if confirmed faulty

Questions and answers

What does B001A mean?

The SRS module detected a fault in the driver's seat belt anchor pretensioner deployment circuit. Wiring, a connector, or the pretensioner itself is the usual cause.

Can I drive with B001A?

You can drive, but the pretensioner may not work in a crash. Get it fixed as soon as possible.

Can I test the pretensioner circuit myself?

You can visually inspect the connector and harness after disconnecting the battery. Electrical testing of SRS circuits is best left to a professional because of the risk of accidental deployment.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.