Airbags

B0012 — Driver Knee Airbag Deployment Control Circuit Fault

Severity: high Drive with care, to a shop

What B0012 means

B0012 means the SRS control module detected a problem in the deployment (squib) circuit of the driver knee airbag. At every key-on the module tests this circuit's resistance and compares it to an allowed range. If there is an open, short, or poor connection, it stores the code and turns on the AIRBAG light.

Symptoms

  • AIRBAG/SRS warning light on or flashing
  • B0012 stored in the SRS module
  • Driver knee airbag disabled
  • Other SRS circuit codes may also be present
  • Light appeared after work on the dash, steering column, or interior

Possible causes

  1. Damaged wiring or connector in the knee airbag circuit (most common)
  2. Corroded or loose terminals under the dash or near the steering column
  3. Faulty knee airbag module or its inflator
  4. Wrong circuit resistance: open, or short to ground or power
  5. Failed SRS control module
  6. Previous deployment or incorrectly replaced parts

How to diagnose

  1. Scan with a tool that reads SRS data and note whether the code is current or history
  2. Ask about recent work on the interior, steering wheel, seats, or dash
  3. Inspect the yellow SRS harness and connectors under the dash and at the steering column for damage, corrosion, or poor seating
  4. Check connector locks and terminals for bent or pushed-out pins
  5. Disconnect the battery, wait the time the manufacturer specifies, then measure circuit resistance using only the service-manual method
  6. Never probe a squib with a standard multimeter, which could trigger deployment
  7. Substitute a known-good module or an approved load tool if the manual allows
  8. Clear the code and see if it returns

Common fixes

  • Repair or replace damaged wiring and connectors
  • Replace the driver knee airbag module
  • Replace and program the SRS control module if confirmed faulty
  • Clean terminals and fully secure the connectors

Questions and answers

Is it safe to drive with B0012?

The car will run, but the knee airbag, and possibly other SRS parts, may not work in a crash. Get it diagnosed soon.

Can I just clear the B0012 code?

Clearing may turn the light off briefly, but a real fault will bring it back. Find the cause first, especially at connectors and wiring.

Can I test the airbag circuit myself?

Only by following the service procedure: disconnect the battery, wait, and never apply voltage to the squib. If unsure, use a shop experienced with SRS.

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.