liminfoSiemens Fault Code Reference
Siemens PLC & Drive fault/error code reference with causes and solutions
About Siemens Fault Code Reference
The Siemens Fault Code Reference provides a searchable database of 50 diagnostic and fault codes across five categories of Siemens automation equipment: PLC Diagnostics (16#2940 module errors through 16#2963 PROFINET station events), CPU & System (16#4300 CPU stop through 16#4564 array index errors), SINAMICS Drive (F07011 motor overtemperature through F30011 fan failure), PROFINET & IO (16#C940 station failure through 16#C949 real-time communication errors), and Safety (16#6940 F-CPU program changes through 16#6944 discrepancy errors).
Each fault code includes a detailed cause analysis listing 3-5 root causes and a numbered resolution procedure with 4-6 specific troubleshooting steps. The SINAMICS section covers 15 drive faults including motor overtemperature (F07011), locked rotor (F07012), phase loss (F07015), overcurrent (F07801), DC link overvoltage (F07802), encoder failure (F07902), and power unit faults (F30001-F30011).
This tool is designed for Siemens TIA Portal users, automation engineers, and industrial maintenance teams working with S7-1200, S7-1500, ET200, and SINAMICS G120/S120/V90 equipment. All data runs locally in your browser, enabling fast offline diagnosis in factory environments without internet access.
Key Features
- S7-1200/1500 PLC diagnostic codes: module errors (16#2940-2945), process interrupt loss, station failure, and PROFINET return events
- CPU & System faults: memory reset, CPU stop, firmware issues, cycle time overload, battery warnings, memory card errors, and program exceptions
- 15 SINAMICS drive fault codes: F07011-F07902 motor faults and F30001-F30011 power unit faults with parameter references
- PROFINET & IO: station failure/return, configuration errors, substitute values, IP conflicts, name assignment, and RT communication faults
- F-CPU Safety codes: safety program changes, F-I/O passivation, PROFIsafe communication errors, safety shutdown, and discrepancy detection
- Each code includes TIA Portal diagnostic buffer event IDs for direct cross-reference
- Filterable by 5 equipment categories with full-text search across all 50 fault codes
- Responsive dark mode layout optimized for tablets and phones used in field maintenance
Frequently Asked Questions
What does Siemens error 16#2942 mean?
16#2942 means a wrong module type was inserted in a slot. The module order number does not match the HW Configuration in TIA Portal. Verify the inserted module part number matches the project, replace with the correct type, update module firmware if needed, or modify the HW Config to match the actual module installed.
How do I resolve SINAMICS fault F07011 (motor overtemperature)?
F07011 indicates the motor thermal model or PTC/KTY sensor detected excessive temperature. Check the motor cooling fan operation, reduce load to within rated range, verify ambient temperature and ventilation, check parameters P0604 (warning limit) and P0605 (fault limit), and inspect motor temperature sensor wiring. Allow the motor to cool before resetting.
What causes Siemens PLC error 16#2944 (watchdog)?
16#2944 is a watchdog timeout meaning the program scan time exceeded the configured limit. Causes include infinite loops, excessive computations, or communication load. Optimize program logic, increase maximum cycle time in CPU properties (with caution), distribute logic across multiple OBs, and check PROFINET communication load.
How do I read the S7-1500 diagnostic buffer in TIA Portal?
In TIA Portal, go to Online & Diagnostics > Diagnostics buffer. The buffer shows timestamped events with hex event IDs (e.g., 16#2940). You can filter by event type and time range. Programmatically, use SFC51 (RDSYSST) with SZL-ID W#16#00A0 to read diagnostic entries from your PLC program for custom alarm handling.
What does SINAMICS F07802 (DC link overvoltage) mean?
F07802 occurs when the DC bus voltage exceeds the limit, typically during motor deceleration when regenerative energy raises the bus voltage. Increase deceleration time (P1121), install or verify braking resistor operation, enable Vdc_max controller (P1240), measure supply input voltage, and check DC link capacitor condition.
How do I fix PROFINET IO station failure (16#C940)?
16#C940 means a PROFINET IO device is not responding. Check the device power and LEDs, inspect PROFINET cables (Cat5e or higher) and RJ45 connectors, verify network switch port link status, perform a ping test, and check the device status in TIA Portal topology view. When replacing a device, remember to reassign its PROFINET name and IP address.
What is Siemens F-CPU safety error 16#6942?
16#6942 indicates a PROFIsafe communication error between the F-CPU and F-I/O module. The PROFIsafe monitoring time (F_WD_Time) may have been exceeded, or a CRC error occurred indicating data integrity failure. Check the PROFINET/PROFIBUS network, verify F_WD_Time is not too short, inspect cables for EMC interference, and confirm PROFIsafe addresses (F_Source_Add/F_Dest_Add) match.
Is this Siemens fault code reference free to use?
Yes, this reference is completely free with no usage limits, no account registration, and no software download required. All 50 fault codes across 5 categories are instantly searchable. The tool runs entirely in your browser, making it ideal for offline use with tablets on the factory floor during maintenance and commissioning.