OBD Guide

U012F

Lost Communication With Generator B Control Module

U012F is an OBD-II diagnostic trouble code meaning: Lost Communication With Generator B Control Module. Common causes: broken or damaged wires in the communication circuit, generator control module b malfunction. Estimated repair cost: $22–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$22–167 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced charging system efficiency
  • Unstable operation of electrical equipment
  • Floating engine speed
  • Error message on the dashboard

Causes

  • Broken or damaged wires in the communication circuit
  • Generator control module B malfunction
  • Control module power problems
  • Short circuit in communication circuit
  • Software failure in the ECU

How to Fix

  1. Check the integrity of the wiring harness to generator module B
  2. Diagnose power and ground of the control module
  3. Check communication with the module using a diagnostic scanner
  4. Flash or replace generator control module B (if necessary)
  5. Eliminate possible corrosion in connectors

Related codes

Error U012F by Vehicle Brand

FAQ

What does the U012F code mean?

U012F is an OBD-II diagnostic trouble code that indicates: Lost Communication With Generator B Control Module

What causes a U012F error code?

The most common causes of U012F include: Broken or damaged wires in the communication circuit; Generator control module B malfunction; Control module power problems; Short circuit in communication circuit.

How do I fix a U012F diagnostic trouble code?

To fix U012F: Check the integrity of the wiring harness to generator module B. Diagnose power and ground of the control module. Check communication with the module using a diagnostic scanner. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U012F?

Yes, but get it checked soon

How much does it cost to fix U012F?

The estimated repair cost for U012F is $22–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat