OBD Guide

B3979

Incorrect Environmental Identifier Received from HVAC Control Module

B3979 is an OBD-II diagnostic trouble code meaning: Incorrect Environmental Identifier Received from HVAC Control Module. Common causes: hvac module malfunction, broken or damaged wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Incorrect operation of climate control
  • Errors on the HVAC system display
  • Incorrect temperature or humidity readings

Causes

  • HVAC module malfunction
  • Broken or damaged wiring harness
  • Software error
  • HVAC Module Power Problems

How to Fix

  1. Diagnostics of communication with the HVAC module
  2. Checking the integrity of the wiring harness
  3. HVAC Module Software Update
  4. Replacing the HVAC module if necessary

Related codes

Error B3979 by Vehicle Brand

FAQ

What does the B3979 code mean?

B3979 is an OBD-II diagnostic trouble code that indicates: Incorrect Environmental Identifier Received from HVAC Control Module

What causes a B3979 error code?

The most common causes of B3979 include: HVAC module malfunction; Broken or damaged wiring harness; Software error; HVAC Module Power Problems.

How do I fix a B3979 diagnostic trouble code?

To fix B3979: Diagnostics of communication with the HVAC module. Checking the integrity of the wiring harness. HVAC Module Software Update. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3979?

Yes, but get it checked soon

How much does it cost to fix B3979?

The estimated repair cost for B3979 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat