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Haas CNC Alarm Codes - VF, ST, Servo, Spindle, ATC

⚡ Quick Answer

Haas CNC alarm guide for VF and ST machines: 100-series stops, low lube, spindle alarms, servo faults, ATC errors, and reset checks.

⚡ AT A GLANCEScroll down for full repair guide
What it meansHaas VF and ST alarms group E-stop and safety stops, air or lube faults, axis and servo faults, spindle alarms, ATC faults, and soft-limit conditions.
Most likely causeCommon causes include open safety circuits, low way-lube level, low shop air, overloaded cuts, encoder signal loss, ATC sensor faults, carousel obstruction, and spindle-drive faults.
First checkRead the full alarm text and history first, then verify the E-stop chain, way-lube reservoir, shop air, tool load, spindle encoder wiring, ATC home sensors, and cabinet power.
⏱Repair time10-30 minutes for reset, air, lube, and obstruction checks; longer for servo drive, spindle encoder, ATC, or safety-circuit work
🔧Part neededISO 68 way lube oil, spindle encoder coupling, ATC proximity sensor, machine safety relay, cabinet power supply
Repair intent

Need this fixed instead of diagnosed?

Haas CNC alarm guide for VF and ST machines: 100-series stops, low lube, spindle alarms, servo faults, ATC errors, and reset checks.

Parts to price first

Check the part before you book service.

ISO 68 way lube oil

Part: Mobil Vactra No. 2 equivalent

Use for low-lube alarms after confirming the Haas way-lube reservoir and pump requirements.

Haas spindle encoder coupling

Price after Alarm 116 or orientation faults point to a cracked encoder coupling.

CNC proximity sensor

Relevant for ATC arm or carousel position faults after mechanical obstruction is ruled out.

Machine safety relay

Check only after tracing the E-stop circuit and matching the relay voltage and contact rating.

Haas CNC Alarm Codes — Quick Reference

Haas CNC machines (VF series, ST lathes, HS high-speed, EC palletizers) display alarm numbers on the control screen. Alarms in the 100s are generally E-stop/safety alarms; 110–120s are axis and servo faults; 120–134 are spindle and coolant faults. Higher-number alarms cover ATC, pallet changer, and soft-limit conditions.

AlarmMeaningCommon Fix
101E-stop pressedRelease E-stop; check wiring
102Power supply faultCheck control cabinet power supply
103Door interlock activeClose machine door(s)
104Feed hold activeClear feed hold; check wiring
105Low lube oilAdd way lube oil; check pump
106Low air pressureCheck shop air supply; regulator
107High coolant temperatureCheck coolant level and cooler
108Axis servo faultCheck servo drive and motor
110Spindle servo faultCheck spindle drive
111X-axis faultCheck X servo and encoder
112Y-axis faultCheck Y servo and encoder
113Z-axis faultCheck Z servo and encoder
114A-axis faultCheck A-axis servo
115Spindle overloadReduce depth of cut; check tool
116Spindle encoder faultCheck encoder cable and disc
117Spindle motor thermal faultCheck spindle motor temperature
118Coolant motor faultCheck coolant pump
119Spindle orientation faultCheck spindle encoder; orient dog
120ATC faultCheck ATC mechanism
125Carousel faultCheck carousel rotation and sensors
134Spindle drive alarmSpindle drive internal fault

Most Common Codes

Alarm 101: E-Stop Pressed

The E-stop circuit is open. Check: (1) the red E-stop button on the control panel — is it pulled out? (2) all E-stop buttons around the machine (some have external buttons on doors or pedestals), (3) the E-stop chain in the control cabinet — a broken wire or relay in the E-stop safety circuit causes 101 without any button being pressed. On Haas machines with safety mats, also check the mat connectors.

Alarm 105: Low Lube Oil

The way lube reservoir is low or the lube pump failed. Fill the reservoir with approved way lube oil (Mobil Vactra No. 2 or equivalent ISO 68 way oil). If the reservoir is full and alarm still appears, check the lube pump output — remove the outlet line and verify oil flows on command (lube is commanded at machine startup). A clogged lube distributor block is common on older machines.

Alarm 106: Low Air Pressure

Shop air is below the minimum required (typically 85 PSI). Check the pneumatic supply regulator on the back of the machine — it should show 85–100 PSI. Also check for large air leaks from the pneumatic cylinder (drawbar release) or coolant mist manifolds. Air pressure alarms during active machining can indicate the shop compressor is undersized.

Alarm 115: Spindle Overload

The spindle drive exceeded its current limit, usually from aggressive cutting parameters. Reduce the depth of cut, feed rate, or spindle speed. Also check: tool condition (dull tool = high force), tool stickout length (excessive reach causes chatter and load spikes), and workholding security.

Alarm 120: ATC (Automatic Tool Changer) Fault

The tool changer failed to complete a cycle. Check: (1) hydraulic pressure on machines with hydraulic ATC — minimum 1000 PSI, (2) pocket sensor on side-mount tool changers — verify the arm is at the home position, (3) tool retention — a tool that won’t release from the spindle causes ATC arm jams. On VF models with umbrella ATC, check that the carousel rotated to the correct pocket.

The tool carousel failed to index to the commanded tool pocket. Check the carousel motor, the proximity switches that detect carousel position, and verify no tools are physically obstructing carousel rotation (an oversized tool in an adjacent pocket can cause this).

Alarm 116: Spindle Encoder Fault

The spindle encoder is not providing a clean signal. Check the encoder cable connection at the encoder and at the spindle drive. On older Haas machines, the encoder coupling (a flexible plastic disc) wears and creates intermittent signals — visible as a cracked or missing coupling when inspecting the back of the spindle motor.

Resetting Alarms

  1. Fix the root cause of the alarm.
  2. Press RESET on the Haas control.
  3. Press POWER UP if the machine was in an E-stop condition.
  4. For servo alarms after unexpected movement, verify axis positions are correct before running a program.

Parts Often Needed

PartNotes
Way lube oilMobil Vactra No. 2 (ISO 68) — 1 gallon
Spindle encoder couplingHaas P/N for flexible disc coupling
ATC arm sensorProximity switch for arm home position
E-stop relaySafety relay in control cabinet

Technician Tips

CNC alarms should always be diagnosed by reading the full alarm text, not just the number. Modern Fanuc, Haas, and Mazak controls provide detailed alarm descriptions — press the help key while viewing the alarm for diagnostic suggestions. The alarm history screen stores the last 50-100 alarms with timestamps; review this before clearing to identify patterns. A servo alarm (SV series on Fanuc) that appears only during rapid traverse points to a different cause than one that appears during cutting.

Prevention: Back up your CNC parameters monthly. Battery-backed memory faults are much easier to recover when you have a current parameter, ladder, offset, and macro backup. Replace control batteries on a planned maintenance schedule before voltage drops far enough to risk data loss.

Need Replacement Parts?

Before ordering, match the machine-control part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.

When to Call a Pro

Alarms 108, 111–114 (servo faults on any axis) that persist after a power cycle indicate servo drive or motor issues that require Haas factory service or a Haas certified technician to diagnose. Haas provides phone support 24/7 for production-down situations.

Quick FAQ

What does Haas alarm 105 mean?

Alarm 105 means the way-lube reservoir is low or the lube pump is not delivering oil. Fill with approved ISO 68 way oil, then check pump output if the alarm returns.

What causes Haas alarm 116?

Alarm 116 points to a spindle encoder signal problem. Check the encoder cable and inspect the flexible coupling disc on older machines for cracks or missing pieces.

When should I call Haas service for servo alarms?

Call Haas service when alarms 108 or 111 through 114 return after a power cycle, because persistent servo drive or motor faults need certified machine diagnosis.


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