General Specification Electrical Function gmw3110 General Motors Local Area Network Enhanced Diagnostic Test Mode Specification

GM WORLDWIDE ENGINEERING STANDARDS 
GMW3110 
© Copyright 2010 General Motors All Rights Reserved 
February 2010 
Page 10 of 336 
3. A Request Message Definition section which 
includes: 

Tables to define the structure of the request 
message. 

A sub-function parameter definition section 
with text and table descriptions of any 
sub-level functions within the diagnostic 
service. 

A request message data parameter definition 
section with text and table descriptions of any 
additional data bytes used in the request 
message. 
4. A Response Message Definition section which 
includes: 

Tables to define the structure of the positive 
response message. 

A response message data parameter definition 
section with text and table descriptions of any 
additional data bytes used in the response 
message. 

A section which defines specific negative 
response codes supported by the test mode 
service. 
5. A 
Message Flow Example
section using 
tables to represent the flow of messages 
between the tester and target node. 
6. A 
Node Interface Function 
section which 
provides: 

An interface data dictionary specific to the 
particular diagnostic service. 

Interface pseudo code specific to the test 
mode. 

Suggested verification procedures to validate 
proper implementation of the diagnostic 
service. 

A section describing any special case 
implications specific to test tools and their 
implementation of the diagnostic services. 
The following provides more detailed descriptions 
and examples of specific diagnostic service 
documentation sections and or table examples. 
3.1 Request Message Sub-Function Parameter