OBD Guide

B27B4

Electric Compressor Low Voltage System

B27B4 is an OBD-II diagnostic trouble code meaning: Electric Compressor Low Voltage System. Common causes: electric compressor malfunction, problems with wiring or harness. 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
  • Increased engine temperature
  • Check Engine light comes on
  • Reduced cooling system efficiency

Causes

  • Electric compressor malfunction
  • Problems with wiring or harness
  • Faulty relay or fuse
  • Low battery voltage
  • Problems with the control unit

How to Fix

  1. Check the voltage at the compressor terminals
  2. Inspect the wiring and wiring harness for damage
  3. Check relays and fuses
  4. Test the compressor operation
  5. If necessary, replace the compressor or wiring

Related codes

FAQ

What does the B27B4 code mean?

B27B4 is an OBD-II diagnostic trouble code that indicates: Electric Compressor Low Voltage System

What causes a B27B4 error code?

The most common causes of B27B4 include: Electric compressor malfunction; Problems with wiring or harness; Faulty relay or fuse; Low battery voltage.

How do I fix a B27B4 diagnostic trouble code?

To fix B27B4: Check the voltage at the compressor terminals. Inspect the wiring and wiring harness for damage. Check relays and fuses. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B27B4?

Limited driving only, diagnose soon

How much does it cost to fix B27B4?

The estimated repair cost for B27B4 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat