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

Table 186: Example of Physical Request for ReadDiagnosticInformation With Sub-Parameter = $82 
T = Frame Sent By Tester, N = Frame Sent By Node, shaded region indicates PCI 
Frame Type 
CAN Id 
#1 
#2 
#3 
#4 
#5 
#6 
#7 
#8 
T(USDT-SF) 
$241 
$03 
$A9 
$82 
$02 
--- 
--- 
--- 
--- 
N1(UUDT) 
$541 
$82 
$00 
$04 
--- 
--- 
--- 
--- 
--- 
: 
N1(UUDT) 
$541 
$82 
$00 
$05 
--- 
--- 
--- 
--- 
--- 
: 
N1(UUDT) 
$541 
$82 
$00 
$04 
--- 
--- 
--- 
--- 
--- 
: 
T(USDT-SF) 
$241 
$03 
$A9 
$82 
$00 
--- 
--- 
--- 
--- 
N1(UUDT) 
$541 
$82 
$00 
$00 
--- 
--- 
--- 
--- 
--- 
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February 2010 
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Table 187 is the same as the example in Table 186, but with negative response message RC_78. 
Table 187: Example of Physical Request for ReadDiagnosticInformation With Sub-Parameter = $82 And 
RC = $78 
T = Frame Sent By Tester, N = Frame Sent By Node, shaded region indicates PCI 
Frame Type 
CAN Id 
#1 
#2 
#3 
#4 
#5 
#6 
#7 
#8 
T(USDT-SF) 
$241 
$03 
$A9 
$82 
$02 
--- 
--- 
--- 
--- 
N1(USDT-SF) 
$641 
$03 
$7F 
$A9 
$78 
--- 
--- 
--- 
--- 
: 
N1(UUDT) 
$541 
$82 
$00 
$04 
--- 
--- 
--- 
--- 
--- 
: 
N1(UUDT) 
$541 
$82 
$00 
$05 
--- 
--- 
--- 
--- 
--- 
: 
N1(UUDT) 
$541 
$82 
$00 
$04 
--- 
--- 
--- 
--- 
--- 
: 
T(USDT-SF) 
$241 
$03 
$A9 
$82 
$00 
--- 
--- 
--- 
--- 
: 
N1(UUDT) 
$541 
$82 
$00 
$00 
--- 
--- 
--- 
--- 
--- 
8.18.6 Node Interface Function. 
8.18.6.1 Node Interface Data Dictionary (Table 188). 
Table 188: Node Interface Data Dictionary of ReadDiagnosticInformation Service Pseudo Code 
Variable/Meaning 
Values 
message_data_length 
TesterPresent_Timer_State 
DTC_send_on_change_flag
Reference Common/Global 
Pseudo Code Data 
Dictionary For Definition Of 
These Flags/Variables 
stored_status_mask 
This variable is used to store the most recently requested status mask in 
association with a message $82 request. 
$00 thru $FF 
dtc_found 
This local flag is used to indicate whether a DTC number/FailureType 
combination requested via message $80 is locally supported. 
TRUE, FALSE 
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February 2010 
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Variable/Meaning 
Values 
send_on_change_count 
This variable is used to store the most recently tabulated count of DTCs 
matching the single tester-defined send-on-change DTC status mask. As soon 
as service $A9 message $82 is activated, the node will calculate the number of 
DTCs satisfying the tester-defined masking criteria and store the count in this 
variable. 
After acknowledging the tester
’s request, the node operating in steady state will 
send updated DTC count information if the current count is different from that 
which is stored in this variable. This variable will then be updated with the 
current count of DTCs satisfying the filtering criteria.
 
$0000 thru $FFFF 
Signed value. 
temp_count 
This is a temporary storage variable for message $82. It is a 2-byte counter 
used to store the current count of DTCs that match the tester-defined filtering 
criteria.
 
$0000 thru $FFFF 
Signed value. 
temp_count_hi 
This is a temporary storage variable for message $82. It is the upper byte of 
temp_count.
 
$00 thru $FF 
temp_count_lo 
This is a temporary storage variable for message $82. It is the lower byte of 
temp_count.
 
$00 thru $FF 
total_num_local_dtcs 
This static variable contains the total number of DTCs any particular node 
supports. (Note that this number is specific to each node).
 
$0001 thru $FFFF 
M 
This is a temporary loop index variable that is used in the pseudo code for 
searching through local DTC lists.
 
$0000 thru $FFFF 
N 
This is a temporary loop index variable that is used in the pseudo code for 
searching through local DTC lists.