Apparently my question is related to VG gurus (According to Chilton only VG Maximas have 5-mode ECU).

I tried to run ECU through all modes tests. Here is what I got.
Mode 1. Heated Oxygen Sensor.
I started engine and leave it in idle. The green LED was going ON and OFF spontaneously.
Chilton's saying that it turns ON when lean condition is detected, and turns OFF under a rich condition. Well... Why it's blinking? Is it a normal behavour?

Mode 2. Mixture Ratio Feedback Control Monitor.
The same behaviour as for Mode 1 except both lamps goes ON and OFF.
Again - why blinking?

Mode 3. Self-Diagnosis System.
Got 55. Good.

Mode 4. On/Off Switches.
While cranking engine red lamp turned ON which means that starter switch works. Good.
Depressed the accelerator. According to Chilton the red lamp should go OFF. It went ON and remained ON while depressing pedal. Is it just a mistake in Chilton?

Mode 5. Real Time Diagnostics.
Lamps weren't flashing. Good? I think about leaving ECU in mode 5 while driving.

I appreciate any comments you guys can give me about Mode 1, 2, and 4 behaviour. Is it ok or not?