What the 15074 alarm means

The safety-relevant channel between the controller and a drive (RDC / KPP / KSP path) reports a fault; safe motion supervision is compromised and the system stops. This is one of the faults our repair team handles on KUKA KRC2 / KRC4 / KRC5 (KSS) systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • Damaged RDC, KPP or KSP, or encoder line
  • X11 safety wiring fault
  • CCU-to-KPP/KSP power connection problem
  • Failing drive safety circuit
Field note: the first item on this list is what we find most often on real machines. Check it before you go deeper.

Step-by-step field fix

  1. Check the X11 wiring and the CCU–KPP/KSP power connections
  2. Inspect the RDC and encoder cables for damage
  3. Swap-test the suspected KSP/KPP module
  4. Replace the faulty component and re-run the safety acceptance test
Safety first: never bypass safety circuits or force contactors closed. If the alarm involves E-stop chains, brakes or drive power, and you are not a trained robot technician, contact a professional — wrong moves here can cost you a robot or an injury.

Still stuck? Get an engineer on the phone — right now

Tell us the alarm code, the robot model and what was happening when the alarm came up. Our engineers run these diagnostics every day, and remote diagnosis by phone or video call is free.

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Related Safety Chain & E-Stop alarms

1001 — Operator Safety Acknowledgment Required 1002 — Drives-On Not Asserted ($DRIVES_ON) 1010 — Move Enable Missing — E-Stop or Safety Relay Open
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 15074 alarm mean?

The safety-relevant channel between the controller and a drive (RDC / KPP / KSP path) reports a fault; safe motion supervision is compromised and the system stops. In field practice it belongs to the safety chain & e-stop family of faults.

QCan I clear a KUKA 15074 alarm myself?

Sometimes. Work through the step-by-step checks on this page — the first listed cause is what we find most often in the field. If the alarm returns after two attempts, or the fault involves power, brakes or safety circuits, stop and call a qualified robot service engineer.

QHow fast can a Henghuan engineer help?

On-site response in the Pearl River Delta within 30 minutes to 3 hours, across mainland China in 1-3 business days, and worldwide within 2-5 business days. Remote diagnosis by phone/WhatsApp/video is available immediately.

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.