What the 1002 alarm means

The controller is ready but the drives-on command has not been given, so $DRIVES_ON is false and no axis can move. In T1/T2 the enabling switch must be held; in AUT the external drives-on input must be asserted. 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

  • Enabling switch on the SmartPad not pressed or only half-pressed
  • External drives-on button or PLC input not asserted in AUT mode
  • A pending safety message is blocking the drives-on command
  • Contactor or drive chain fault preventing drives-on from completing
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. In manual mode, press the enabling switch to the middle position and request drives on
  2. In AUT mode, verify the external drives-on input is asserted and mapped correctly
  3. Clear all pending messages, then request drives on again
  4. Listen for contactor closure; if absent, diagnose the drive power chain
  5. Check the event log for the stop reason that opened the drives-on circuit
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.

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Related Safety Chain & E-Stop alarms

1001 — Operator Safety Acknowledgment Required 1010 — Move Enable Missing — E-Stop or Safety Relay Open 15074 — Safety Junction Error in Drive — Channel N
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 1002 alarm mean?

The controller is ready but the drives-on command has not been given, so $DRIVES_ON is false and no axis can move. In T1/T2 the enabling switch must be held; in AUT the external drives-on input must be asserted. In field practice it belongs to the safety chain & e-stop family of faults.

QCan I clear a KUKA 1002 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.