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

8.12.6 Node Interface Function. 
8.12.6.1 Node Interface Data Dictionary (Table 137). 
Table 137: Node Interface Data Dictionary of RequestDownload Service Pseudo Code 
Variable/Meaning 
Values 
message_data_length 
Security_Access_Unlocked 
TransferData_Allowed 
Reference Common/Global 
Pseudo Code Data Dictionary 
For Definition Of These 
Flags/Variables 
programming_mode_active 
This is a flag used to keep track of whether or not a programming event has 
been enabled.
 
YES/NO 
8.12.6.2 Node Interface Pseudo Code. 
Powerup States: 
None 
Each time a $34 message is received and the ECU is currently executing the operational software, the 
following logic is executed: 
BEGINFUNCTION Serv_34_Msg_Recvd() 
IF ((message_data_length is invalid) OR (dataFormatIdentifier is invalid) OR ((dataFormatIdentifier != $00) 
AND (unCompressedMemory size is invalid))) THEN 
send Negative Response($7F $34 $12) /* Invalid Format */ 
ELSE 
/* The security access check below only applies to ECUs which support security access */ 
/* the check below for a download in progress is only required for ECUs that do not have boot software. If 
the ECU supports a boot then this check would be handled out of the service $34 boot code */ 
IF ((Security_Access_Unlocked = FALSE) OR (programming_mode_active = NO) OR (a software or 
calibration module download is in progress)) THEN
send Negative Response ($7F $34 $22) /* for conditionsNotCorrect */ 
ELSE 
IF (more than P2
C
ms is needed to process this request) THEN 
send Negative Response ($7F $34 $78) /* RequestCorrectlyReceived-ResponsePending */ 
ENDIF 
/* at this time the module shall do whatever is necessary to prepare for transferring program control to 
the boot software (if the ECU supports boot software) for module programming.*/ 
IF (DTC for Flash or EEPROM checksum failure is set) THEN 
send Negative Response ($7F $34 $99) /*ReadyForDownload-DTCStored */ 
ELSE 
send ($74) response message 
--``,,``````,``,,``,,,`,`,`,,-`-`,,`,,`,`,,`---
CameraLoops.com

---