Siemens F01018 — What It Means
Fault F01018 on a Siemens SINAMICS G120 indicates that the drive’s controller detected repeated interrupted boot attempts during startup. When this happens, the drive automatically reverts to factory settings as a fallback. The fault typically points to an unstable power supply during the power-up sequence, a corrupted parameter set, or an internal CPU issue preventing normal boot completion.
Common Causes
- Unstable or interrupted control power during startup Voltage sags, brown-outs, or intermittent supply during the boot sequence prevent the controller from completing initialization.
- Repeated reboot or reset events Multiple power cycles in quick succession or intermittent supply connections force the drive to abort startup more than once.
- Invalid or corrupted parameterization Startup data stored in the drive is damaged or contains invalid values that prevent the controller from booting normally.
- Loose or corroded supply terminals Poor connections at the incoming power or control terminals cause intermittent contact during the critical power-up phase.
- Failing control-unit module or CPU Internal electronics in the control unit crash repeatedly during boot, triggering the fault even when external power is stable.
Step-by-Step Fix
- Fully power down the drive and disconnect all supply power, then wait for the DC bus to discharge completely before attempting any further action.
- Power the drive back on once only and observe whether F01018 reappears immediately or if the drive completes a normal boot cycle.
- Check incoming power supply stability by measuring line voltage during startup with a meter to confirm no sags or drops occur, and inspect all power and control terminals for loose, corroded, or intermittent connections.
- Read the fault buffer in the drive’s diagnostics menu to review the complete fault history and check for other startup-related errors that preceded F01018.
- Inspect and verify drive parameterization by reviewing commissioning data and startup parameters for invalid or corrupted values, or reload a known-good parameter set from backup.
- Test with a clean power cycle after correcting any supply or parameter issues, and monitor the drive through several full startup sequences to confirm stable operation.
- Replace or reprogram the control unit if F01018 persists after confirming stable supply power and valid parameters, since repeated boot interruption points to a control-side hardware failure rather than an external load problem.
Parts Often Needed
| Part | Notes |
|---|---|
| G120 Control Unit Module (CU) | Amazon | Required if repeated boot failures persist after supply and parameter checks. Confirm your exact G120 model and CU variant before ordering. |
| Siemens parameter backup memory card | Amazon | Useful for restoring known-good parameter sets if corrupted commissioning data is suspected. |
When to Call a Pro
Call a qualified Siemens technician or certified drive specialist if F01018 returns immediately after a clean power cycle and you have confirmed stable incoming power and valid parameterization. Repeated boot interruptions that survive basic supply and parameter troubleshooting usually indicate an internal control-unit fault requiring specialized diagnostic tools, firmware updates, or module replacement. If the drive is mission-critical or connected to expensive machinery, professional support will prevent extended downtime and avoid damage from trial-and-error parts swapping.