System Reference Code List

A System Reference Code or SRC is used by the AS/400 service processor to inform the system operator of what the system is doing during IPL or if a critical error has occurred and the system must be shut down immediately. The System Attention light will be illuminated if the service processor detects a fault condition.

Most AS/400s display the SRC as a 4-bit value, however, the SRC is technically two 2-bit values: the first two bits indicate where in the IPL process the system was when it stopped, while the latter two bits indicate the item that caused the fault. As such, this list will be maintained as two separated 2-bit values.

Usually, a given SRC can be found verbatim across every model of machine. However, some IBM manuals indicate the second bit as 'xx' meaning they may change from system to system. We recommend searching only by the latter 2-bit code. Codes requiring further troubleshooting steps and actions will be linked on their own separate page.

Pre-IPL / Early IPL Power Checks
SRC	Description
0000 BBBB	Time-of-Day Clock Battery Dead Non-fatal error. Replace the clock battery. System will still IPL when this SRC is active.
0000 CCCC	Control Panel Communications Failure
0000 000C	Attempted to IPL with Emergency Power Off turned off CISC only - return the EPO switch to the On position and attempt IPL again
Service Processor IPL
SRC	Description
B1xx 4511	MFIOP Failure Fatal error
5251-2	1977
OS/400 IPL
SRC	Description
5251-1	1977
5251-2	1977
Software Crash
SRC	Description
5251-1	1977
5251-2	1977
Hardware Fault
SRC	Description
5251-1	1977
5251-2	1977