Nissan Repair: finding trouble codes, crankshaft position sensor, air flow meter

Question
How do I pull code from my 84 300zx? I removed the ecu &
see the red & green light in computer,but do not who how to
receive codes.Please advise.
                            THANKS

Answer
Leonard,

This should work for your 300ZX on reading the codes and clearing them.

Diagnostic Trouble Codes
Nissan
11     Crankshaft Position Sensor
12     Air Flow Meter
13     Cylinder Head Temperature Sensor
21     Ignition Signal
22     Fuel Pump
23     Throttle Valve Switch
31     Load Signal
32     Start Signal
41     Fuel Temperature Sensor
44     System Okay
1.   Verify that diagnostic mode slesctor is turned fully counterclockwise.
2.   Turn ignition switch ON.
3.   Make sure inspection lamps stay on. (Bulb check.)
4.   Ture diagnostic mode selector fully clockwise.
5.   Make sure inspection lamps display code 23 and 31.
6.   Depress accelerator pedal and release.
7.   Make sure inspection lamps display code 31.
8.   Start engine, apply brakes and shift into "D" position.
9.   Make sure inspection lamps display code 31.
10.   Turn a load switch OFF-ON-OFF. (A/C switch, Headlight switch etc.)
11.   Shift into "P".
12.   Make sure inspection lamps display code 44. Any other code is a DTC.