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 27 of 336 
Table 11: OBD CANId Assignments for Enhanced Diagnostics 
OBD 
ECU 
OBD/Enhanced Diagnostic
Physical Request CANId 
OBD/Enhanced Diagnostic
Physical Response CANId 
Enhanced Diagnostic UUDT 
Response CANId 
1 
$7E0 
$7E8 
$5E8 
2 
$7E1 
$7E9 
$5E9 
3 
$7E2 
$7EA 
$5EA 
4 
$7E3 
$7EB 
$5EB 
5 
$7E4 
$7EC 
$5EC 
6 
$7E5 
$7ED 
$5ED 
7 
$7E6 
$7EE 
$5EE 
8 
$7E7 
$7EF 
$5EF 
 
Note:
Usage of OBD/EOBD CAN Identifiers for enhanced diagnostics does not have any effect on the 
maximum number of ECUs allowed on the HSCAN network. 
4.4.5 SPS Special Case ECU Programming CANId Assignments. 
The reserved diagnostic CAN Identifiers 
outlined in Table 7 are the CAN Identifiers used for diagnostics on ECUs which are either: 

Programmable via the Service Programming System (SPS) and have been completely programmed, 
or

Fully functional ECUs which are not programmable via the Service Programming System. 
The reserved diagnostic CAN Identifiers are further referenced in this document as permanent diagnostic CAN 
Identifiers. An ECU which is SPS programmable and has not been completely programmed (e.g., an ECU 
shipped to a vehicle assembly plant with boot and operational software and no calibration data), may or may 
not comprehend its permanent diagnostic CAN Identifiers. This may be the case where a corporate common 
SPS programmable ECU is used across multiple platforms and the platforms are not able to standardize the 
permanent diagnostic CAN Identifiers. 
Note:
It is also possible for an SPS programmable ECU which is not completely programmed to be able to use 
its permanent diagnostic CAN Identifiers during programming. This would require that the ECU have the 
permanent diagnostic CAN Identifiers stored in memory which is accessible to the software executing upon 
boot while the ECU is not completely programmed. 
In order to avoid the proliferation of part numbers on SPS programmable ECUs solely due to diagnostic CANId 
conflicts across platforms, special case SPS CAN Identifiers have been defined. Each ECU requiring the 
special case CAN Identifiers shall support a special case point-to-point USDT diagnostic request CANId 
(further referenced as the SPS_PrimeReq CANId) and a special case USDT diagnostic response CANId 
(further referenced as the SPS_PrimeRsp CANId). Table 12 defines the assignment of the special case CAN 
Identifiers to the ECU.