What is the amber symbol under figure 20 on rev counter

What's the color of the smoke? white, white with a blueish color, or black?

ever heard of the FSM. book
no year stated
no car stated or is it a truck.
so cant look it up. lacking facts like that. nor VIN.
why post just the engine name.
you do know that injection systems vary by year, and countries laws, right?
call Isuzu on the phone, and ask for the factory service manual.
guessing ends.

Look in your owners manual

Can also find those symbols on the internet

I have a similar problems on my 2005 9-3. It has developed a number of minor electical issues. including dial and false warning light triggers. I have fixed most of them by simply going round the car disconnecting the electical connectors and spraying "switch cleaner" (Maplin or Radio Shack).
The only problem I have left is the rev counter occasionally starts reading high, removing the fuse (end of dash panel - 4th fuse down) for about 30s with engine off normally resets everything back to normal.
Hope that helps.

I couldn't figure this same problem out so I ordered a factory replacement via EBAY for $20 and my son-in-law put it in while I was at work! Do you have a great son-in-law, too?

diesel engines don't rev as high as gas engines and electronic controls don't allow over running the engine in neutral

Please ask a local mechanic to have a look as this sort of fault is not uncommon and could be the ignition key chip so try spare key ,a faulty ECU or even something simple like a mass air flow sensor or a blocked catalytic exhaust so its favourite to ask a local man then post what he says for verification

that sounds like the check engine light. if you happen to live in the states stop by an autozone and they will scan the codes for free and let you know what is causing it.

I also have a G35 05. This is not an error. The REV light is within a circle, this is a gauge. This gauge also has an amber light in it which blinks or stays on solid based on settings you control. This can be controled with your trip selector button. This button has multiple functions, as you press it, your trip A counter will show, then your trip B counter, then your REV light indicatior setting. this is where you set the RPM limit. If you wish to change the RPM limit to a higher or lower setting, press and hold the trip selector button until the display starts blinking. Then press multible times until you get to the RPM's your looking for. Now when you approch the RPM's selected, the light will start blinking and once your reach them, the light will stay on solid.

Check throttle position sensor.