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 131 of 336 
8.8.6.2 Node Interface Pseudo Code. 
Powerup States: 
SPS_Bad_Key_Counter 

2 
SPS_Security_Key_Allowed 

FALSE 
DevCtrl_Bad_Key_Counter 

2 
DevCtrl_Security_Key_Allowed 

FALSE 
DeviceContol_Security_Level 

SERVICE 
IF ((Vulnerability_flag=$FF) OR (manufacturers_enable_counter > 0))THEN 
Security_Delay_Timer 

0 
ELSE 
Security_Delay_Timer 

10 
ENDIF 
Each time a $27 message is received, the following logic is executed: 
BEGINFUNCTION Serv_27_Msg_Recvd() 
IF (more than P2
C
ms is needed to process this request) THEN 
send Negative Response ($7F $27 $78) /* RequestCorrectlyReceived-ResponsePending */ 
ENDIF 
IF ( $Level != $00 AND $Level != $FF AND 
(($Level MOD 2=$01 AND message_data_length = 2) OR
($Level MOD 2=$00 AND message_data_length = 4))) THEN 
SELECT FIRST 
WHEN ($Level=$01) 
IF (Security_Delay_Timer > 0) THEN 
Send ($7F $27 $37) /* Time Delay Not Expired */ 
ELSE 
IF ((Vulnerability_flag=$FF) OR (manufacturers_enable_counter > 0)) THEN 
Security_Access_Unlocked 

TRUE 
ENDIF 
IF (Security_Access_Unlocked=TRUE) THEN 
TesterPresent_Timer_State 

ACTIVE 
Send ($67 $01 $00 $00) message 
ELSE 
Send ($67 $01 $Seed) message 
SPS_Security_Key_Allowed 

TRUE 
ENDIF 
ENDIF 
WHEN ($Level=$02) 
IF (SPS_Security_Key_Allowed=TRUE) THEN 
SPS_Security_Key_Allowed 

FALSE 
IF ($Key does not match stored key) THEN 
SPS_Bad_Key_Counter 

SPS_Bad_Key_Counter - 1 
IF (SPS_Bad_Key_Counter = 0) THEN 
Security_Delay_Timer 

10 s 
SPS_Bad_Key_Counter 

1 
send ($7F $27 $36) /* for Exceeded Number Of Attempts */ 
--``,,``````,``,,``,,,`,`,`,,-`-`,,`,,`,`,,`---
CameraLoops.com

---