ISO 15765-4:2005 pdf download

ISO 15765-4:2005 pdf download.Road vehicles -Diagnostics on Controller Area Networks(CAN)—Part 4: Requirements for emissions-related systems.

4.2.1 Request message transmit procedure
The purpose of the 11 bit CAN identifier verification procedure is to determine whether 11 bit CAN identifiers are being used in legislated-OBO communication and, wi multiple baudrates e specified in the baudrateReccwd parameter, to determine the baudrate to be used in such communication.
The following transmit procedure shall be used to transmit the request message of the 11 bit CAN identifier verification procedure. The transmit procedure contains provisions for legacy vehides which use either CAN (same or different physical layer as defined for legislated 080) or a different protocol (non CAN) on the CAN pins of the ISO 15031.3 diagnostic connector.
Where the vehicle uses a CAN with a physical layer different from that specified for legislated OBD (Clause 8) or a non-CAN protocol on the CAN pins of the OBD connector, the transmit procedure given as follows shall guarantee that in all cases the external test equipment will detect that the vehicle does not support CAN as specified for legislated OBD and will stop the transmission of the request message immediately.
Where the vehicle uses CAN and the physical layer according to Clause 8, the transmit procedure given as follows shall guarantee that in all cases the external test equipment will detect that ii uses the wrong baudrate for the transmission of the request message and will stop disturbing the CAN bus immediately. Under normal in-vehicle conditions (i.e. no error frames during in-vehicle communication when the external test equipment is disconnected), the external test equipment will disable its CAN interface prior to the situation where the internal error counters of the OBD ECU(S) reach critical values.