National Instruments CAN 372139B-01 - Manual (Page 87)

Chapter 5 Automotive Diagnostic Command Set API for LabVIEW
© National Instruments Corporation 5-61 Automotive Diagnostic Command Set User Manual
Output
diag ref out is a copy of diag ref in. You can wire it to subsequent
diagnostic VIs.
seed out returns the seed from the ECU.
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.
Description
The usual procedure for getting a security access to the ECU is as follows:
1. Request a seed from the ECU using RequestSeed.vi with access mode = n.
2. From the seed, compute a key for the ECU on the host.
3. Send the key to the ECU using SendKey.vi with access mode = n + 1.
4. The security access is granted if the ECU validates the key sent. Otherwise, an error is
returned.