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

8.9.6.2 Node Interface Pseudo Code. 
Powerup States: 
None 
Each time a $28 message is received, the following logic is executed: 
BEGINFUNCTION Serv_28_Msg_Recvd() 
--``,,``````,``,,``,,,`,`,`,,-`-`,,`,,`,`,,`---
CameraLoops.com

---

GM WORLDWIDE ENGINEERING STANDARDS 
GMW3110 
© Copyright 2010 General Motors All Rights Reserved 
February 2010 
Page 139 of 336 
IF (message_data_length != 1) THEN 
IF (diagnostic_responses_enabled = YES) THEN 
Reject the request with a ($7F $28 $12) for invalid format 
ENDIF 
ELSE 
IF (Device cannot disable normal communications at this time) THEN 
/* do not need to check if diag resp enabled here because if they are not, then there would be no 
reason why the device would not already have disabled normal comm */ 
Reject the request with a ($7F $28 $22) for conditions not correct 
ELSE 
Diag_Services_Disable_DTCs 

TRUE 
normal_message_transmission_status 

DISABLED 
CALL hnd_halt_normal_comm() /* handler call to halt normal comm */ 
TesterPresent_Timer_State 

ACTIVE 
IF (diagnostic_responses_enabled = YES) THEN
Send ($68) response message 
ENDIF 
ENDIF 
ENDIF 
ENDFUNCTION 
8.9.7 Node Verification Procedure. 
Perform procedures 1 and 2 below on devices that are completely 
programmed (SPS_TYPE_A ECU). 
Procedure 1: 
1. Send a DisableNormalCommunication request with data bytes after the Service Id and verify the negative 
response ($7F $28 $12) message is sent. 
2. Send a DisableNormalCommunication request message at a time when the device cannot disable Normal 
Mode communication and verify the negative response ($7F $28 $22) message is sent. (This is only 
required for devices which support such a situation.)