OBD Guide
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B1921

Air Bag Diagnostic Monitor Ground Circuit Open

B1921 is an OBD-II diagnostic trouble code meaning: Air Bag Diagnostic Monitor Ground Circuit Open. Common causes: broken ground wire, corrosion of contacts in connectors. 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
  • SRS system does not pass self-diagnosis
  • No response from the module to the OBD-II scanner

Causes

  • Broken ground wire
  • Corrosion of contacts in connectors
  • SRS Diagnostic Module Malfunction
  • Wiring harness damage

How to Fix

  1. Check ground continuity using a multimeter
  2. Inspect connectors for corrosion or damage
  3. Check the condition of the SRS wiring harness
  4. If necessary, replace the diagnostic module

Related codes

B1920B1922B1000

FAQ

What does the B1921 code mean?

B1921 is an OBD-II diagnostic trouble code that indicates: Air Bag Diagnostic Monitor Ground Circuit Open

What causes a B1921 error code?

The most common causes of B1921 include: Broken ground wire; Corrosion of contacts in connectors; SRS Diagnostic Module Malfunction; Wiring harness damage.

How do I fix a B1921 diagnostic trouble code?

To fix B1921: Check ground continuity using a multimeter. Inspect connectors for corrosion or damage. Check the condition of the SRS wiring harness. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1921?

Do not drive — repair immediately

How much does it cost to fix B1921?

The estimated repair cost for B1921 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat