6ES7222-1HF22-0XA0 SIMATIC S7-200

Common Diagnostic Codes

Fault Code 1

CPU configuration error — the expansion module configuration does not match the hardware connected to the CPU.
Verify the hardware configuration in STEP 7 Micro/WIN matches the physical module order and type. Re-download the configuration to the CPU.

Fault Code 2

I/O bus communication error — the CPU cannot communicate with one or more expansion modules.
Check the I/O expansion cable connections between the CPU and expansion modules. Inspect connectors for damage or corrosion and reseat the module.

Fault Code 3

Output short circuit or overload detected on a relay output channel.
Disconnect the field wiring from the affected output channel and measure the load. Replace any shorted field devices and verify load current does not exceed 2 A per channel.

Fault Code 4

Module not recognized — the CPU detects a missing or unresponsive expansion module.
Power down the system, reseat the expansion module, and verify the module is correctly connected in the expansion chain. Replace the module if the fault persists.

Fault Code 5

Excessive ambient temperature — the module is operating outside its rated temperature range.
Measure cabinet temperature and ensure it does not exceed 55 °C. Improve ventilation or add cooling to the control cabinet.

Fault Code 6

Output relay coil failure — one or more relay outputs are not switching correctly.
Use a multimeter to verify continuity across the relay contacts when the output is commanded ON. If the relay does not switch, the module requires replacement.

Fault Code 7

5 V DC bus undervoltage — insufficient power supplied from the CPU to the expansion module.
Calculate total 5 V DC current consumption of all expansion modules and verify it does not exceed the CPU's rated 5 V bus current. Remove non-essential modules or upgrade to a CPU with higher bus current capacity.