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

Procedure 2: 
1. Send functionally addressed $22 request message for one $PID that is supported by the ECU and does 
not require security access (use $101 AllNode CAN Id and $FE AllNode functional system). Verify proper 
response, containing the data of the requested $PID (test data formatting). 
2. If applicable, send a functionally addressed $22 message for a $PID that is supported by the ECU, where 
the PID is a secure $PID and the ECU is locked. Verify there is no response. 
3. If applicable, use service $27 to access security then repeat the request from the previous step. Verify the 
proper positive response and data. 
4. Send functionally addressed $22 request message for two $PIDs (if the ECU supports multiple PIDs in a 
single request) where only one of the requested PIDs is supported by the ECU and does not require 
security access (use $101 AllNode CAN Id and $FE AllNode functional system). Verify proper response, 
containing the only the data of the supported unsecure $PID. 
5. If applicable, repeat the last procedure but include a secure PID in the request. Ensure that this is done at 
a time when security access has not been granted. Verify the proper response for the unsecure PID and 
that no data is reported for the secure PID. 
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GMW3110 
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6. If applicable, use service $27 to access security and then repeat the previous procedure. Verify that the 
proper response is sent including data for all PIDs in the request. 
7. Send a functionally addressed $22 message with less than 2 bytes in the $PID field (0 or 1 data byte after 
the service indentifier $22). Verify the negative response ($7F $22 $12 - SubFunctionNotSupported-
InvalidFormat). 
8. Send a functionally addressed $22 message with more data bytes than allowed per the maximum request 
message length (see pseudo code above). Verify the negative response ($7F $22 $12 - 
SubFunctionNotSupported-InvalidFormat). 
9. Send a correctly formatted functionally addressed $22 message for a $PID that is not supported by the 
ECU. Verify there is no response. 
10. If the ECU supports the use of negative response code $78, send a functionally requested $22 message to 
the ECU with a valid $PID where the ECU needs more than P2
C
ms to read data bytes from memory and 
send the positive response. Verify that the ECU sends the negative response ($78 - 
RequestCorrectlyReceived-ResponsePending) within P2
C
ms followed by a positive response (reference 
application timing section of this specification).
11. (If applicable) Send a functional request for a valid $PID at a time when ECU internal conditions would not 
allow the data to be retrieved (e.g., EEPROM failure) and verify that the ECU sends the correct negative 
response ($7F $22 $22 ConditionsNotCorrect). 
12. If applicable, send a functionally addressed $22 message for a $PID that is supported by the ECU, where 
the PID requires a security code
(as defined
in the Vehicle Theft Deterrent SSTS)
and the security code 
has not been entered. Verify there is no response. 
13. If applicable, enter the security code then repeat the request from the previous step. Verify the proper 
positive response and data. 
14. If applicable, send functionally addressed $22 request message for two $PIDs (if the ECU supports 
multiple PIDs in a single request) where only one of the requested PIDs is supported by the ECU (use 
$101 AllNode CAN Id and $FE AllNode functional system), but include a secure code required PID in the 
request. Ensure that this is done at a time when the security code has not been entered. Verify the proper 
response for the unsecure PID and that no data is reported for the secure PID. 
15. If applicable, enter the security code and then repeat the previous procedure. Verify that the proper 
response is sent including data for all PIDs in the request.