ISO 15031-4:2005 pdf download.Road vehicles - Communication between vehicle and external equipment for emissions-related diagnostics —Part 4: External test equipment.
For vehicles using ISO 9141-2. service $01 PlO $00 request shall be used as the idle message.
For vehicles using ISO 14230-4. the service TesterPresent is the recommended way to satisfy the idle message requirement as specified in ISO 14230-4, Aiternatively, the service 501 PID 500 as specified in ISO 15031-5 may be used.
If during the initialization of the ISO 15765-4 (CAN) protocol the external test equipment receives a negative response message(s) fran, the emissions-reLated ECU(s) with the negative response code (NRC) $21 busy-RepeatRequest the external test equipment is required to perform five (5) retries (repeat request message as specified in ISO 15765-4) The reception of NRC $21 busy-RepeatRequest during the initialization Nidicates that an On-board diagnostic tester may be active and is currently diagnosing one or multiple emissions-related ECUs. The On-board tester and vehicle ECU(S) shall complete the in-progress communication. Thés may take several seconds The external test equipment shaM continue to initialize the ISO 15765-4 (CAN) protocol until it receives a positive response or aborts after five (5) seconds have expired (measured alter the completion of the fIfth (5th) re-try).
If none of the protocol tests shown above succeeds, the equipment shall repeat all of them and advise the user:
a) that communication with the vehicle could not be established.
b) to confirm that the ignition key Is still In the 0N position.
For vehicles using ISO 14230-4. the service TesterPresent is the recommended way to satisfy the idle message requirement as specified in ISO 14230-4, Aiternatively, the service 501 PID 500 as specified in ISO 15031-5 may be used.
If during the initialization of the ISO 15765-4 (CAN) protocol the external test equipment receives a negative response message(s) fran, the emissions-reLated ECU(s) with the negative response code (NRC) $21 busy-RepeatRequest the external test equipment is required to perform five (5) retries (repeat request message as specified in ISO 15765-4) The reception of NRC $21 busy-RepeatRequest during the initialization Nidicates that an On-board diagnostic tester may be active and is currently diagnosing one or multiple emissions-related ECUs. The On-board tester and vehicle ECU(S) shall complete the in-progress communication. Thés may take several seconds The external test equipment shaM continue to initialize the ISO 15765-4 (CAN) protocol until it receives a positive response or aborts after five (5) seconds have expired (measured alter the completion of the fIfth (5th) re-try).
If none of the protocol tests shown above succeeds, the equipment shall repeat all of them and advise the user:
a) that communication with the vehicle could not be established.
b) to confirm that the ignition key Is still In the 0N position.
