1.15.19 Diagnosis of CAN Data Bus - VVT communication

U1172 (CVVTsig), U1174 (CVVTnpl) 

The diagnosis of the local CAN communication between VVT control module and PCM is done by supervision of the received VVT local CAN messages.

If a VVT local CAN message is missing for a calibrated period of time, a timeout is detected and a CVVTsig fault will be set.

If the checksum or the sequence number of a VVT local CAN message is wrong for a calibrated period of time, a malfunction is detected and a CVVTnpl fault will be set.