Appendix A. Interpreting Firmware Error Codes

The error code is an 8-character (4-byte) hexadecimal code produced by firmware to

identify the potential failing function or FRU in a system. It consists of 5 source code

characters and 3 reason code characters. Individual characters within the error code

have specific field definitions, as defined in the following tables. Table A-1 and

Table A-2.

Table A-1. Service Reference Code Field Layout

Source Code Reason Code
Byte 0 Byte 1 Byte 2 Byte 3
S1 S2 S3 S4 S5 R1 R2 R3

Table A-2 (Page 1 of 2). Service Reference Code Field Descriptions

Field Description
S1
Maintenance Package Source that produced the error code.
0 Reserved
1 Reserved
2 POST, Firmware
3 BIST
4Service Processor, base system controller, etc.
5 Reserved
8Product specific service guide, MAPs
9 Reserved
A-F Reserved
S2 Base class
S3-S4 Sub-class
S5 Unique version of the device/FRU type for a particular product.
R1
Device/FRU unique failure reason codes.
1-7 Use in combination with R2, R3 for diagnostic test failure when
maximum isolation was obtained.
8-9 Use in combination with R2, R3 for diagnostic test failure when
maximum isolation was NOT obtained.
ALog analysis of POST error log
BLog analysis of machine check or checkstop error log
C Reserved
DDiagnostic detected missing resource
E-F Reserved
Appendix A. Interpreting Firmware Error Codes A-1