Ultra3000 fault codes: E05, E09, E20, E34, E50 explained

How to read E codes on the Ultra3000 seven-segment display, the flashing L, the SERCOS and DeviceNet LEDs, common codes (E05, E09, E10, E20, E30, E34, E37, E43, E50…), what to check and how to plan the replacement.

An Ultra3000 servo drive (Bulletin 2098) reports a fault on its seven-segment status display: it shows an E, then flashes the two-digit error code one digit at a time, and repeats until the problem is cleared (2098-IN003E-EN-P, p. 4-3). E, 2, 0 means E20. A flashing L is not a fault code: the drive is in an overtravel condition and motion is restricted. The full list is in chapter 4, "Troubleshooting Status Indicators" (pp. 4-3 to 4-8). Rockwell lists the 2098-DSD drives as discontinued; each end-of-life page, such as 2098-DSD-010, gives the replacement Rockwell lists.

What the display tells you first

With the Logic Power LED on (p. 4-3):

Status display	Drive type	Meaning
Segments cycling in a full circle	2098-DSD-xxx, -xxxX, -HVxxx and DeviceNet (-DN) drives	Drive ready
Fixed 4	SERCOS drives (-SE)	Drive ready
Flashing E and two digits	All	Drive has an error
Flashing L	All	Overtravel condition, motion restricted

If the PWR indicator is off, check the AC power or the auxiliary +5 V logic power. On 2098-DSD-005, -010 and -020 drives with external +5 V auxiliary power, PWR on with the status display off can mean the auxiliary supply is too low: the manual asks for 5.10 to 5.25 V measured at the drive terminals (p. 4-3).

Common error codes

Code	Name in the manual	Usual causes	What to check
E04	Motor Overtemperature	Motor thermostat trips: high ambient or excessive current, wiring, wrong motor	Continuous torque rating at ambient (40 °C max), cooling, motor wiring and selection (p. 4-4)
E05	IPMFault	Shorted motor cable or winding, drive too hot, above continuous rating, IPM failure	Cable continuity, turn the motor by hand, vents and fan, reduce acceleration (p. 4-4)
E06	Hardware Overtravel (SERCOS only)	Dedicated overtravel input inactive	Wiring, motion profile (p. 4-4)
E09	Bus Undervoltage	Low AC line or AC power input	Incoming AC level, glitches or line drops (p. 4-4)
E10	Bus Overvoltage	Excessive regeneration or AC input too high	Deceleration profile, shunt wiring and fuse, larger system (p. 4-5)
E11	IllegalHall State	Hall phasing or connections	Hall wiring, 5 V supply to the encoder (p. 4-5)
E18	Overspeed Fault	Motor above 125 % of maximum rated speed	Cable noise, tuning (p. 4-5)
E19	Excess Position Error	Position error limit exceeded	Feedforward gain, following error limit, position loop tuning (p. 4-5)
E20	Motor Encoder State Error	Illegal encoder transition: noise, bonding, bad encoder	Shielded twisted-pair cable, routing, grounds, high-frequency bond of motor to panel (p. 4-6)
E22	Motor Thermal Protection Fault	Internal motor thermal filter tripped	Acceleration, duty cycle, motion time, size, tuning (p. 4-6)
E23	IPM Thermal Protection Fault	Internal drive thermal filter tripped	Same checks as E22 (p. 4-6)
E30	Encoder Communication Fault	No communication with an intelligent encoder	Motor selection, automatic identification support, encoder wiring (p. 4-7)
E34	Ground Fault	Wiring error, motor ground short, internal fault	Motor power wiring; test with motor cable removed (p. 4-7)
E35	Precharge Fault	Low AC input voltage or internal fault	AC voltage on all phases (p. 4-7)
E37	AC Line Loss	One or more AC input phases missing	AC voltage on all phases (p. 4-7)
E39	Self-sensing Commutation Startup Error	Motion for self-sensing startup obstructed	Hard limits at startup, self-sensing current, wiring diagnostics (p. 4-8)
E40 / E41	230V / 460V Shunt Protection Fault	Shunt resistor ineffective or excessive regeneration	Shunt connected, shunt fuse, resistance value, motor not driven mechanically (p. 4-8)
E43	Drive Enable Input (SERCOS only)	Software enable with hardware input inactive, or input dropped while enabled	Drive Enable input active whenever the drive is enabled through software, or disable the Drive Enable Input fault (p. 4-8)
E50	Duplicate Node Fault (SERCOS only)	Two drives with the same SERCOS node address	Unique node address on every drive (p. 4-8)

E05 has one more cause on 2098-DSD-005, -010 and -020 drives with external +5 V auxiliary power: enabling less than 1.0 second after main AC is applied (p. 4-4). Codes listed as RESERVED (E07, E08, E38 and others) mean: call your Rockwell representative (pp. 4-4, 4-7, 4-8).

The documentation update 2098-DU003B-EN-P (09/2006) adds E44, a lost-motion fault on applications with Stegmann feedback: absolute position in the drive is incorrect after a line-loss condition; cycle power and re-home the drive if it was homed in the same power cycle (p. 2 of the update).

SERCOS and DeviceNet status LEDs

LED	State	Meaning
SERCOS Module Status	Flashing red-green	DC bus low: normal on auxiliary power only, otherwise read the error code
SERCOS Module Status	Flashing red / steady red	Recoverable fault / unrecoverable fault
SERCOS Network Status	Flashing red	No communication: loose or broken fiber, or receive and transmit swapped
SERCOS Network Status	Flashing green	Still establishing communication, or node address does not match the controller
DeviceNet Module Status	Flashing red / steady red	Recoverable fault (power cycle or reset) / unrecoverable fault
DeviceNet Network Status	Flashing red	I/O connection timed out
DeviceNet Network Status	Steady red	Duplicate MAC ID or bus-off: check addresses, media and data rate

Source: pp. 4-9 to 4-10.

Checks, step by step

Record the code before any reset: E and both digits, the drive catalog number (-SE, -DN or neither) and the LED states.
Power faults (E09, E35, E37): measure AC on all phases at the drive.
E05 and E34: for E05, with all power and motor connections removed, check continuity from the DC bus to U, V and W (p. 4-4). For E34, disconnect the motor cable and enable with the current limit set to 0; if the fault clears, the cause is wiring or the motor (p. 4-7).
Encoder faults (E11, E20, E21, E30, E31): cable shield and twisted pairs, routing away from noise, grounds and bonding. E31 Encoder Data means corrupted encoder data: replace the motor or encoder (p. 4-7).
Regeneration (E10, E40, E41): deceleration profile and the shunt resistor, including its fuse.
SERCOS faults (E43, E50, Network LED): enable input, node addresses and fiber cables.

Clearing faults safely

Find and correct the cause before operating again; do not defeat or override the drive fault circuits. Before working on the drive, measure the DC bus voltage or wait the time on the drive warning label (p. 4-2). Clearing a fault can restart the machine: follow the plant's permit and lockout rules.

When it is hardware

PWR indicator off with power applied and the supply checked: internal power supply malfunction, call Rockwell (p. 4-3).
E01 Non-Volatile Memory Endurance Exceeded: unrecoverable; the drive must go back to the factory (p. 4-3).
E14 on SERCOS (-SE) drives, SERCOS Hardware Fault: contact Rockwell. On DeviceNet (-DN) drives E14 means the DeviceNet network is broken: troubleshoot the network first (p. 4-5).
Steady red Module Status LED: unrecoverable fault (pp. 4-9 to 4-10).

Planning the replacement

Ultra3000 drives are discontinued, so a fault that points to hardware is a good moment to plan the move to a current drive. The replacement Rockwell lists for each 2098-DSD catalog number is on its end-of-life page, and the migration options are in Kinetix servo drive migration. For an engineer on site: breakdown support.

Frequently asked questions

How do I read an Ultra3000 error code?

The seven-segment display shows an E, then flashes the two-digit code one digit at a time, and repeats until the problem is cleared (2098-IN003E-EN-P, p. 4-3). E, 2, 0 means E20.

What does a flashing L mean on an Ultra3000?

The drive is in an overtravel condition and motion restrictions are in effect. It is not an error code (p. 4-3).

What is error E20 on an Ultra3000?

E20 Motor Encoder State Error means the motor encoder made an illegal transition. Check for noise: shielded twisted-pair cable, routing, grounds and the high-frequency bond of the motor to the panel; replace the motor or encoder if it continues (p. 4-6).

What does E34 Ground Fault mean on an Ultra3000?

A wiring error, a motor internal ground short or an internal fault. Disconnect the motor power cable and enable with the current limit set to 0: if the fault clears, the cause is wiring or the motor; if it remains, call Rockwell (p. 4-7).

Sources

Rockwell Automation, 2098-IN003E-EN-P, Ultra3000 Digital Servo Drive Installation Manual, 04/2004 — chapter 4 "Troubleshooting Status Indicators" (pp. 4-1 to 4-10)
Rockwell Automation, 2098-DU003B-EN-P, Ultra3000 Digital Servo Drive Installation Manual documentation update, 09/2006 — error code E44 (p. 2)

Read 13 November 2026. This article paraphrases the sources and does not quote them; read the original documents before designing or working on a system. Links open the latest edition in Rockwell's literature library; page numbers refer to the edition cited.