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

GM WORLDWIDE ENGINEERING STANDARDS 
GMW3110 
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February 2010 
Page 178 of 336 
Procedure 2: 
1. Send a service request message which requires a TesterPresent service to remain active (excluding 
service $A5). 
2. Send functionally addressed TesterPresent ($3E) request messages with an invalid message length (not 
equal to 1) and verify that no negative response message is sent by the node (ECU). 
3. Verify that the node (ECU) sends a ReturnToNormalMode positive response message between P3
C
and 
P3
Cmax
. 
Procedure 3: 
(Uses Functional TesterPresent message).
 
1. Send a service request message to the node using a service that requires a TesterPresent to keep its 
functionality active (e.g., schedule periodic DPID via $AA service or use DeviceControl $AE service). Pick 
a service where it can be easily verified that the functionality remains active if TesterPresent messages are 
sent. 
2. Wait 2 s. 
3. Send a valid functionally addressed TesterPresent ($3E) request message using the AllNodes CANId 
($101) + AllNodes extended address ($FE). 
4. Verify that no TesterPresent positive response message is sent by the node (ECU). 
5. Send no further messages and wait for a P3
C
timeout to occur. Verify that the node (ECU) sends a 
ReturnToNormalMode positive response message between P3
C
and P3
Cmax
. Also verify that the 
functionality of the other service has stopped once the ReturnToNormalMode positive response message 
has been sent. 
Procedure 4: 
(Uses Physical TesterPresent message). 
1. Send a service request message to the node using a service that requires a TesterPresent to keep its 
functionality active (e.g., schedule periodic DPID via $AA service or use DeviceControl $AE service). Pick 
a service where it can be easily verified that the functionality remains active if TesterPresent messages are 
sent. 
2. Wait 2 s. 
3. Send a valid physically addressed TesterPresent ($3E) request message.
4. Verify that a TesterPresent positive response message is sent by the node (ECU). 
5. Send no further messages and wait for a P3
C
timeout to occur. Verify that the node (ECU) sends a 
ReturnToNormalMode positive response message between P3
C
and P3
Cmax
. Also verify that the 
functionality of the other service has stopped once the ReturnToNormalMode positive response message 
has been sent. 
Procedure 5: 
1. Repeat Procedures 3 and 4 only continue to send TesterPresent messages within the P3
C 
timing window 
for at least one minute. Verify that the service activated in step 1 of these procedures continues to function 
as long as the TesterPresent messages are sent. After the P3
C
timeout occurs, verify that the node (ECU) 
sends a ReturnToNormalMode positive response message (between P3
C
and P3
Cmax
) and that the 
functionality of the other service has stopped once the ReturnToNormalMode positive response message 
has been sent. 
Procedure 6: 
1. Send a ReturnToNormalMode ($20) request to an ECU and verify the positive response. 
2. Send a valid functionally addressed $3E request to the node and verify that there is no response. 
3. Wait P3
Cmax
and verify that no unsolicited mode $20 response is sent. 
4. Send a valid physically addressed $3E request to the node and verify the positive response. 
5. Wait P3
Cmax
and verify that no unsolicited mode $20 response is sent.