What the 1004 alarm means

KSS has detected corruption or a read/write failure on the controller's internal storage — programs, archives or boot files may be unreadable, and startup can be blocked. We see this alarm constantly when servicing KUKA KRC2 / KRC4 / KRC5 (KSS) systems, and the first on-site pass usually pins down the cause.

Most common causes

  • Worn or failing industrial SSD/HDD (bad sectors, read-only lock)
  • Improper shutdown or power loss during a write operation
  • Corrupted SQL or configuration database
  • Interrupted software update or archive restore
Field note: Based on our handling experience the first cause is the most frequent — use it as your starting point.

Step-by-step field fix

  1. Create a full archive backup immediately while the controller is still accessible
  2. Check storage health: SMART errors, BIOS detection, SATA cables
  3. Review recent power-loss or forced-shutdown events
  4. Restore affected files from the last known-good archive
  5. If the alarm returns, replace the SSD and rebuild the controller image with the KUKA recovery stick
Safety first: For KUKA 1004, the risk on this family is not injury but data: lose the program, parameters and calibration data and weeks of teaching work start over. The self-serviceable action is Create a full archive backup immediately while the controller is still accessible; anything past that falls under program and calibration data and needs a certified engineer.

How we diagnose system alarms on site

KUKA 1004 belongs to the system & program family. On KUKA 1004 the failing stage is KSS (KUKA System Software) (KRC2 / KRC4 / KRC5) on the KRC2 / KRC4 / KRC5 - the software layer: corrupted program or parameter files, boot failures, version mismatch, memory and storage media. We start reading KUKA 1004 at the smartPAD message window (KSS message numbers: 1xxx operator, 2xxxx drive) with KPP/KSP module LEDs.

The chain involved in KUKA 1004 runs: storage media (CF / flash / disk) -> system software and firmware -> parameters and calibration data -> user programs -> runtime.

Worn or failing industrial SSD/HDD (bad sectors, read-only lock) on KUKA 1004 often traces to a version combination: A solid share of system alarms comes from mismatched version sets: controller firmware upgraded while pendant software, drive configuration or a vision option stayed behind, so boot-time validation fails. Another flavour is a swapped main board or storage media whose system image carries hardware configuration that no longer matches reality. We line up firmware version, software version, option list and actual hardware config and find the one that disagrees. No hardware needed - but the matching recovery media is.

Field notes on this page cover KUKA 1004 (File System Error); written by the Henghuan repair team, updated 2026-10-01.

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Related System & Program alarms

1015 — No Program Selected 1020 — Pending Message Not Acknowledged ($CONF_MESS) 1030 — External Start Missing ($EXT_START) 15102 — SmartPad (Teach Pendant) Fault
Same family: this code belongs to the System & program alarms family - the page collects all System & program-family codes we have handled, with the common inspection order and spares.
Other brands: we also keep field-fix libraries for ABB · Yaskawa · Universal Robots and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the KUKA 1004 alarm mean?

KSS has detected corruption or a read/write failure on the controller's internal storage — programs, archives or boot files may be unreadable, and startup can be blocked. We see this alarm constantly when servicing KUKA KRC2 / KRC4 / KRC5 (KSS) systems, and the first on-site pass usually pins down the cause. KUKA 1004 sits in the system & program family; on our work orders the highest-frequency trigger for this code is "Worn or failing industrial SSD/HDD (bad sectors, read-only lock)".

QCan I clear a KUKA 1004 alarm myself?

Whether KUKA 1004 clears on its own depends on the outcome of "Create a full archive backup immediately while the controller is still accessible". Finish the flow with "If the alarm returns, replace the SSD and rebuild the controller image with the KUKA recovery stick" to confirm KUKA 1004 - do not skip it. If that step is clean, the second most frequent cause on KUKA 1004 is "Improper shutdown or power loss during a write operation". After clearing KUKA 1004, watch it for one shift. A second trip means stop and let an engineer arrive with the right test gear for program and calibration data.

QWhen you handle KUKA 1004, will my programs and frames get lost?

The commonest causes we see on KUKA 1004 are "Worn or failing industrial SSD/HDD (bad sectors, read-only lock), Improper shutdown or power loss during a write operation, Corrupted SQL or configuration database", so we stock the van against those. For KUKA 1004 specifically, we carry recovery media and common storage media, but on this family the backup matters more than the spare. For KUKA 1004, on system alarms the first move is backup; we can walk the customer through preserving data remotely before anything else. Before we roll, tell us what KUKA 1004 shows on the smartPAD message window (KSS message numbers: 1xxx operator, 2xxxx drive) with KPP/KSP module LEDs and what the machine was doing - phone or video triage is free.

This page on KUKA 1004 was written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your KUKA documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by KUKA.