OBD Guide

B1121

Left Air Bag Satellite Sensor

B1121 is an OBD-II diagnostic trouble code meaning: Left Air Bag Satellite Sensor. Common causes: open or short circuit in the sensor circuit, damage to the sensor itself. Estimated repair cost: $56–167.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–167 (est.)

Symptoms

  • Airbag light is on
  • The passive restraint system may not engage in an impact from the left side.
  • Error B1121 is stored in the ECU memory

Causes

  • Open or short circuit in the sensor circuit
  • Damage to the sensor itself
  • Corrosion of contacts or connectors
  • Wiring Harness Problems
  • Malfunction of the main airbag control unit

How to Fix

  1. Conduct diagnostics of the passive safety system
  2. Check the integrity of wiring and contacts
  3. Inspect the sensor for damage
  4. Replace sensor if necessary
  5. Clear error codes and check if B1121 returns

Related codes

FAQ

What does the B1121 code mean?

B1121 is an OBD-II diagnostic trouble code that indicates: Left Air Bag Satellite Sensor

What causes a B1121 error code?

The most common causes of B1121 include: Open or short circuit in the sensor circuit; Damage to the sensor itself; Corrosion of contacts or connectors; Wiring Harness Problems.

How do I fix a B1121 diagnostic trouble code?

To fix B1121: Conduct diagnostics of the passive safety system. Check the integrity of wiring and contacts. Inspect the sensor for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1121?

Do not drive — repair immediately

How much does it cost to fix B1121?

The estimated repair cost for B1121 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat