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

Setup (Pre-Utility File). 
This is a single path consisting of all the steps necessary to identify the target 
node(s), and prepare the GMLAN link(s) for the programming event. All steps of the pre-utility file 
process, except certain steps required for the verification process, are functionally addressed to all 
nodes on the GMLAN sub-networks. 
2. 
Utility File. 
These are all the steps defined within the utility file(s) for the target node(s). This may be a 
single path of steps (in the case of a single node being programmed or multiple nodes programmed 
sequentially), or multiple paths if multiple nodes are being programmed in parallel (multiple utility files 
running in parallel). This path also includes steps to conclude a programming event (synchronization 
between utility files running in parallel). All diagnostic services contained in one utility file are physically 
addressed to the ECU to be programmed to allow for parallel programming. 
9.4.1 Read Identification Information Process. 
The following steps are required to read the necessary 
identification data out of the vehicle in order to retrieve the correct data out of the SPS data base. All steps are 
performed automatically they are not utility file driven. See Table 227. 
Note:
All steps defined are required for field service programming and are not necessarily required for 
assembly plant programming. 
Table 227: Steps of the RequestInfo Process 
Step 
Action 
1 
Wake-up link(s) - 
High voltage wake-up for SWCAN 
- gateways may cascade wake-ups (where 
applicable) across to the other subnets on the vehicle or the tester may need to use 
level $04
of 
diagnostic service 
InitiateDiagnosticOperation ($10)
to generate the wake-up (functionally 
addressed to gateway ECUs only). 
Note:
The tester must allow at least 500 ms after issuing a 
wake-up before transmitting any diagnostic request message (including tester present) to allow the 
ECU to process the wake-up and transition to a communication active state 
– see paragraph 6.1 for 
wake-up requirements. 
2 
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