First the problem: My sil stopped working when accelerating the car. I.e. driving. lol. It still lights up at start up so I think the light itself is ok. No cel(s) or anything. Any suggestions? Fuse? Relay?
Second: What is the main purpose of the sil?
1) Is it to show the OPTIMUM time to shift as far as milegage?
2) Is it to say: "ok shift now, you've gone far enough"?
As to the above two questions: please state:
a) Your opinion
b) Your actual experience. lol
According to the owners manual it's telling you when to shift so that you can get the best FE. They did this because they were afraid that most people would not feel right about cruising at 1000 RPM and would stay in a lower gear.
As far as the SIL, there's not a whole lot to it. It's lit by a single pink wire coming from the ECU. Try retrieving the codes from the ECU. The only reason for it not to illuminate (assuming the bulb is good) is if you're in limp mode for some reason.
There's no relay and it's not on it's own specific fuse.
I currently have to get a new 02 sensor for my VX, but for the short few miles that the 02 works before the CEL comes on the shift indicator will work. CEL comes on, SIL goes off. So, that leads me to believe once you have a new 02 sensor, baring any other problems, the SIL should start to work again.