Hope this helps..
In order to comply with EU directives to provide generic EOBD diagnostics, Nissan fitted the 16 pin (OBD II style) connector to ALL later models. However as EOBD compliance what not mandatory on DIESELS for another 3 years after the petrol models, the connector was just a re-worked version of the old Nissan Consult interface. Consult II.
The upper connector is a 16 pin Consult wired connector
The lower connector is the 14 pin variant. The obvious difference is the 16 pin connector has 2 ground connections, Data ground & Chassis Ground. You should use the Data ground (pin 5). Also there is no requirement to provide a clock signal on the 16 pin connector.
There is an additional power connection on the 16p connector
14 16
1 - 13 ~RXD
2 - 12 ~TXD
6 - 1 ~Check (used to initiate MIL check)
7 - 8 ~+VE from IGN
14 - 5 ~ Data ground
13 - -~Clock signal to ECU. Not used on 16P
The clock signal is not required on all 14P interfaces, it depends on the ECU type fitted. It may work without it.
OBD II/EOBD compliant 16 pin connectors will have additional connections to these shown.
