Code 231-C038: Voltage monitoring CC%2 voltage ID: %4
Issue Description & Safety Warning
The Heidenhain TNC Series CNC has triggered a critical Voltage monitoring CC%2 voltage ID: %4 alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
[Cause of error] - The voltage monitoring of the CC supply voltage reports an error in the CC displayed. - The cause of the error message could be the 5 V power supply of the CCs over the power bus (X69). With large line lengths on the power bus, the 5 V power supply may have to be wired additionally over X74. (Use short line lengths and large line cross section, and check voltage drops on lines between X74.) - Defective power supply unit in the supply module (5 V power pack in the UV). [Error correction] - Establish a 5 V supply between the supply module and the CCs via X74 - Check the 5 V power supply (usually on supply module X74) - Check the 5 V power supply on all CCs (X74/CC) - Check the supply bus (X69) - Check the wiring: - Wiring of the supply bus (X69) - Wiring of the 5 V supply (X74) - Check the cable length of the supply bus (X69), if necessary use double lines - Check the 5 V supply voltage at X74 of all CCs if necessary, increase the wire cross sections or reduce the cable length - Check the voltage attenuation on the cable between X74 on the supply module and X74 on the CCs - Exchange the power supply - Exchange defective hardware (CC) - Inform your service agency, stating the alarm number and Voltage ID
Source: HEIDENHAIN NC Error Messages — TNC7/640/620/320/128, CNC PILOT 640, MANUALplus 620 (10/2023)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Heidenhain TNC Series CNC Alarms
Heidenhain controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 231-C038 on the TNC Series CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Heidenhain's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4497 Heidenhain TNC Series CNC codes.
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