OBD Guide

B1139

Diagnosis Sensor Unit

B1139 is an OBD-II diagnostic trouble code meaning: Diagnosis Sensor Unit. Common causes: damage to the srs diagnostic module, short circuit or break in the wiring harness. Estimated repair cost: $111–556.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$111–556 (est.)

Symptoms

  • SRS/airbag indicator is on
  • Blocking the operation of the passive safety system
  • No diagnostic signal from the module

Causes

  • Damage to the SRS diagnostic module
  • Short circuit or break in the wiring harness
  • Oxidation of module connector contacts
  • Exposure to moisture or corrosion
  • Module software failure

How to Fix

  1. Check the integrity of the wiring harness and module connectors
  2. Clean contacts from oxidation
  3. Scan the module for additional errors
  4. Check the power supply and ground of the module
  5. Replace SRS diagnostic module if necessary

Related codes

FAQ

What does the B1139 code mean?

B1139 is an OBD-II diagnostic trouble code that indicates: Diagnosis Sensor Unit

What causes a B1139 error code?

The most common causes of B1139 include: Damage to the SRS diagnostic module; Short circuit or break in the wiring harness; Oxidation of module connector contacts; Exposure to moisture or corrosion.

How do I fix a B1139 diagnostic trouble code?

To fix B1139: Check the integrity of the wiring harness and module connectors. Clean contacts from oxidation. Scan the module for additional errors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1139?

Do not drive — repair immediately

How much does it cost to fix B1139?

The estimated repair cost for B1139 is $111–556. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat