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

GM WORLDWIDE ENGINEERING STANDARDS 
GMW3110 
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February 2010 
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response with response code $78 is only used with this service when it is possible that the ECU may not be 
able to send any of the requested DPIDs within the P2
C
timing window. The ECU is only allowed to transmit a 
single negative response with response code $78 to a periodic request for this service. Refer to the pseudo 
code (Process_AA_Msgs function for more details). 
Timing of additional UUDT responses is handled in the applications PDS logic. 
8.19.1.3 Stopping Scheduled Periodic DPID(s) - Sub-Function Parameter ($00). 
If a node supports any of 
the periodic levels of this service, then it shall also support the stopSending ($00) sub-function parameter. The 
positive response to a stopSending DPID request is a single UUDT diagnostic message with a value of $00 in 
the DPID/message number position and no additional data bytes. 
When a stopSending request is received without any DPIDs after the sub-function parameter, the ECU shall 
stop the periodic transmission of all DPIDs (stop the PDS) and the entire PDS shall be cleared (cleared = all 
DPIDs removed from the PDS. Reference the pseudo-code for the required implementation). When a 
stopSending request is received with one or more DPID(s) after the sub-function parameter, then all DPID(s) in 
the PDS that match a DPID number in the request shall be stopped. The ECU shall be able to support in a 
single stopSending DPID request, as many DPIDs as there are items in the PDS. Refer to parameter 
PDS_Length in pseudo code. 
Note:
The ECU shall stop only the matching DPIDs. All other scheduled DPIDs shall remain unaffected. A 
stopped DPID shall not be transmitted after the UUDT positive response with message number $00 has been 
sent.