Purpose

Executes the OBD Request Permanent Fault Codes service. All permanent Diagnostic Trouble Codes (DTCs) are read. Format

Input

DTC descriptor is a cluster that describes the DTC records the ECU delivers:
DTC Byte Length indicates the number of bytes the ECU sends for each DTC. The default is 2.
Status Byte Length indicates the number of bytes the ECU sends for each DTC's status. The default is 0 for OBD.
Add Data Byte Length indicates the number of bytes the ECU sends for each DTC's additional data. Usually, there is no additional data, so the default is 0.
Byte Order indicates the byte ordering for multibyte items:
0:MSB_FIRST (Motorola) (default)
1:LSB_FIRST (Intel)
The VI interprets the response byte stream according to this description and returns the resulting DTC records in the DTCs cluster array.
diag ref in specifies the diagnostic session handle, obtained from Open Diagnostic on CAN FD.vi and wired through subsequent diagnostic VIs. Normally, it is not necessary to manually manipulate the elements of this cluster.
error in is a cluster that describes error conditions occurring before the VI executes. If an error has already occurred, the VI returns the value of the error in cluster to error out.
status is TRUE if an error occurred. This VI is not executed when status is TRUE.
code is the error code number identifying an error. A value of 0 means success. A negative value means error: the VI did not execute the intended operation. A positive value means warning: the VI executed intended operation, but an informational warning is returned. For a description of the code, wire the error cluster to a LabVIEW error-handling VI, such as the Simple Error Handler.
source identifies the VI where the error occurred.

Output

diag ref out is a copy of diag ref in. You can wire it to subsequent diagnostic VIs.
DTCs returns the resulting DTCs as an array of clusters:
DTC is the resulting Diagnostic Trouble Code. For the default 2-byte DTCs, you can use DTC to String.vi to convert this to readable format as defined by SAE J2012.
Status is the DTC status. Usually, this is a bit field with the following meaning:
BitMeaning
0testFailed
1testFailedThisMonitoringCycle
2pendingDTC
3confirmedDTC
4testNotCompletedSinceLastClear
5testFailedSinceLastClear
6testNotCompletedThisMonitoringCycle
7warningIndicatorRequested
For OBD, this field usually does not contain valid information.
Add Data contains optional additional data for this DTC. Usually, this does not contain valid information (refer to DTC descriptor)
success? indicates successful receipt of a positive response message for this diagnostic service.
error out describes error conditions. If the error in cluster indicated an error, the error out cluster contains the same information. Otherwise, error out describes the error status of this VI.
status is TRUE if an error occurred.
code is the error code number identifying an error. A value of 0 means success. A negative value means error: the VI did not execute the intended operation. A positive value means warning: the VI executed intended operation, but an informational warning is returned. For a description of the code, wire the error cluster to a LabVIEW error-handling VI, such as the Simple Error Handler.
source identifies the VI where the error occurred.