EL
ErrorLib
Brands
||
  1. Home
  2. Fanuc
  3. Macro B CNC Programming
  4. b
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

b

Current Control Circuit Malfunction (ECM)

Fanuc · Macro B CNC Programming

What does b mean?

The circuit responsible for controlling the current of the Energy Charge Module (ECM) has malfunctioned. This is a critical internal fault within the ECM Control Module (A06B-6158-H010), affecting its ability to manage charge and discharge currents, leading to unstable operation.

Common Causes

  • Failure in the current control feedback loop within the ECM.
  • Faulty current sensor reading.
  • Issues with motor phase current detection.
  • ECM control signal inconsistency to motor driver.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Immediately stop the machine using the emergency stop button and open the external Main Circuit Contactor (MCC) of the Power supply.

  2. 2

    Inspect the ECM Control Module (A06B-6158-H010) for any visible signs of damage, such as burnt components, discolored areas, or loose internal connections.

  3. 3

    Check the input power supply to the ECM Control Module for stability and correct voltage levels.

  4. 4

    Verify that all internal connections and wiring within the ECM Control Module, particularly those related to current sensing and control, are secure.

  5. 5

    If no external factors or loose connections are identified, the ECM Control Module (A06B-6158-H010) is likely faulty and requires replacement.

Browse all codes in this manual (26)
Verified technical data. Last updated: April 2026

Related Faults

08Regeneration Excess Alarm1Over-current at Power Running (ECM)2Over-current at Regeneration (ECM)
Source: Fanuc Macro B CNC Programming
Open Manual (Page 588)Search more codes in this manual