OBD Guide

B1138

Diagnosis Sensor Unit

B1138 is an OBD-II diagnostic trouble code meaning: Diagnosis Sensor Unit. Common causes: damage to the srs wiring harness, corrosion of contacts in the diagnostic unit. Estimated repair cost: $56–167.

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

Symptoms

  • The SRS indicator on the dashboard is on
  • The passive safety system may not work in an accident.
  • The error persists after being reset by the scanner

Causes

  • Damage to the SRS wiring harness
  • Corrosion of contacts in the diagnostic unit
  • Internal diagnostic unit fault
  • Problems with power or grounding of the unit

How to Fix

  1. Check the SRS wiring harness for damage.
  2. Inspect the contacts of the diagnostic unit for corrosion
  3. Check power supply and grounding of the unit
  4. Replace the diagnostic unit if necessary
  5. Reset the error and check the system

Related codes

FAQ

What does the B1138 code mean?

B1138 is an OBD-II diagnostic trouble code that indicates: Diagnosis Sensor Unit

What causes a B1138 error code?

The most common causes of B1138 include: Damage to the SRS wiring harness; Corrosion of contacts in the diagnostic unit; Internal diagnostic unit fault; Problems with power or grounding of the unit.

How do I fix a B1138 diagnostic trouble code?

To fix B1138: Check the SRS wiring harness for damage.. Inspect the contacts of the diagnostic unit for corrosion. Check power supply and grounding of the unit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1138?

Do not drive — repair immediately

How much does it cost to fix B1138?

The estimated repair cost for B1138 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat