OBD Guide

B3981

Incorrect Environmental Identifier Received from Electronic Brake Control Module

B3981 is an OBD-II diagnostic trouble code meaning: Incorrect Environmental Identifier Received from Electronic Brake Control Module. Common causes: damage to the wiring harness between modules, corrosion or poor contact in connectors. Estimated repair cost: $56–333.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–333 (est.)

Symptoms

  • Check Engine Light Is On
  • Unstable operation of the stabilization system (ESP)
  • Disabled or incorrect operation of ABS

Causes

  • Damage to the wiring harness between modules
  • Corrosion or poor contact in connectors
  • Software error in one of the modules
  • Malfunction of the EBCM module itself
  • Problems with module power supply

How to Fix

  1. Check the integrity of wires and connectors between modules
  2. Check power and grounding of the EBCM
  3. Read extended trouble codes (if any)
  4. Update module software (if necessary)
  5. Replace EBCM (as a last resort)

Related codes

Error B3981 by Vehicle Brand

FAQ

What does the B3981 code mean?

B3981 is an OBD-II diagnostic trouble code that indicates: Incorrect Environmental Identifier Received from Electronic Brake Control Module

What causes a B3981 error code?

The most common causes of B3981 include: Damage to the wiring harness between modules; Corrosion or poor contact in connectors; Software error in one of the modules; Malfunction of the EBCM module itself.

How do I fix a B3981 diagnostic trouble code?

To fix B3981: Check the integrity of wires and connectors between modules. Check power and grounding of the EBCM. Read extended trouble codes (if any). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3981?

Limited driving only, diagnose soon

How much does it cost to fix B3981?

The estimated repair cost for B3981 is $56–333. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat