OBD Guide
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B277B

HVAC LIN Communication

B277B is an OBD-II diagnostic trouble code meaning: HVAC LIN Communication. Common causes: broken or damaged lin wires, short circuit in lin circuit. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Climate control does not work
  • Incorrect interior temperature
  • The flaps do not switch modes
  • Check Engine Light Is On

Causes

  • Broken or damaged LIN wires
  • Short circuit in LIN circuit
  • HVAC module malfunction
  • Problems with power supply or weight of components

How to Fix

  1. Check the integrity of the LIN wiring harness
  2. Check voltage and ground on HVAC module
  3. Diagnose connected devices (sensors, dampers)
  4. Replace faulty HVAC module if necessary

Related codes

B277AB277CU0155

FAQ

What does the B277B code mean?

B277B is an OBD-II diagnostic trouble code that indicates: HVAC LIN Communication

What causes a B277B error code?

The most common causes of B277B include: Broken or damaged LIN wires; Short circuit in LIN circuit; HVAC module malfunction; Problems with power supply or weight of components.

How do I fix a B277B diagnostic trouble code?

To fix B277B: Check the integrity of the LIN wiring harness. Check voltage and ground on HVAC module. Diagnose connected devices (sensors, dampers). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B277B?

Limited driving only, diagnose soon

How much does it cost to fix B277B?

The estimated repair cost for B277B is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat