Airbags

B0115 — Driver Airbag Module Circuit Fault

Severity: high Drive with care, to a shop

What B0115 means

The SRS control unit measures the resistance of the driver airbag squib circuit and compares it with an allowed range. If it is too high or too low (open, poor contact or short), it stores B0115 and turns on the airbag light. The circuit passes through the clock spring in the steering column.

Symptoms

  • Airbag/SRS light on or flashing
  • Horn or steering wheel buttons not working
  • Cruise control switches dead
  • Driver airbag disabled by the system
  • Problem began after steering column work or a wheel swap

Possible causes

  1. Worn or broken clock spring
  2. Internal fault in the driver airbag module
  3. Poor contact or corrosion in the connector under the column
  4. Steering wheel or module swapped without the required resistor or with an incorrect part
  5. Damaged wiring in the steering column
  6. Faulty SRS control unit (uncommon)

How to diagnose

  1. Scan with a tool that reads SRS codes and note freeze frame data
  2. Find out whether the wheel, airbag or clock spring was recently replaced
  3. Disconnect the battery and wait as the manufacturer specifies, then inspect the airbag and clock spring connectors
  4. Test the horn and wheel buttons; failures point to the clock spring
  5. Check connector seating and signs of corrosion
  6. Never probe the airbag circuit with a multimeter, as it can fire the inflator; use a scan tool or a proper SRS tester/load resistor
  7. Substitute a known good clock spring or a load resistor to compare
  8. Clear the code and confirm it does not return

Common fixes

  • Replace the clock spring
  • Replace the driver airbag module
  • Repair or replace the connector and wiring
  • Install the correct specified part in place of an incompatible one
  • Test and, if needed, replace the SRS control unit

Questions and answers

What does B0115 mean?

The SRS unit found the driver airbag circuit resistance outside the allowed range. The clock spring or the airbag module is the most common culprit.

Can I drive with B0115?

You can, but the driver airbag may not deploy in a crash. Get it repaired soon.

Why are my horn and the airbag light both failing?

The horn and steering wheel controls run through the same clock spring. When it wears out, it can cause the airbag fault and kill the horn or cruise switches at once.

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.