VSS?

katq22 · Post by **katq22** » 30 Jul 2008, 18:46

Hey guys, quick question. I got the factory wiring diagram translated and it mentions an input from a vehicle speed sensor. Did any of either our Piazza's or Gemini's come with this fitted. I am assuming some sort of load sensor and it is like the o2 sensor which is optional and is just the for better fuel economy.

Post by **elky** » 30 Jul 2008, 21:50

not on the gemmy

i suspect the piazza may of had it, being the overly complicated barge that they are!

Post by **IZU069** » 30 Jul 2008, 23:47

The speed sensors are st'd in Piazzas - they are part of the speedo (being taken from the speedo cable that drives an optic chopper; 20 pulses per rev?). This signal may then be divided (by the overdrive comp?, by 10?) before going to the ECU.
See other posts that discuss the ratios, and using Nissan N12/N13 sensors etc (maybe at isuzupiazza.com).

Later Jackaroos & Rodeos also have a speed sensor. Believe it or not - a reed switch adjacent to the st'd mechanical speedo driven magnet. Probably 6 or 8 pulses per cable rev but I'm not sure.

Post by **Poida** » 31 Jul 2008, 16:53

Rodeo Bob did a bit of investigation regarding speed sensors, think he came up with one of the Pulsar sensors as a a suitable alternative to use in place of a Piazza dash unit.

If possible, can we get hold of a copy of any diagrams anyone happens to come across, especially if it has been translated. Any info we can get is useful. I'll post any useful diagrams in tech so everyone has a chance to access them. The only Piazza info I have is for the 4ZC1-T engine so it is not going to be a lot of use in the DOHC application.

katq22 · Post by **katq22** » 31 Jul 2008, 18:22

Poida wrote:If possible, can we get hold of a copy of any diagrams anyone happens to come across, especially if it has been translated.

I have sent you an email with the translated pdf attached.

Post by **IZU069** » 31 Jul 2008, 18:50

From past VSS queries & straights (in other posts - probably OzGem & IsuzuPiazza), I have misc info including the Nissan Pulsar unit (20pulses/rev etc; hall effect output; it screws straight into Isuzu gearboxs replacing the speedo cable) and some "ratio" info.
I'd have to search etc but should be able to gather all the info (let me know if you want it now instead of my round-tuit scheduling).
I may have worked out the Piazza ratios (dividers) but the documentation would hopefully provide this.

Note too that "divide by" circuits are easy; "divide by with even duty-cycle" may be trickier; and multiplication circuits are possible (whether simpler "pulse triggers n-pulses" or proper PLL (Phase-Locked Loop) circuits.

And ditto - ANY information like that is highly sought. And nice to make it "public" to save others' time, but otherwise at least known to the few that responsibly handle & deserve such info.

Greengem20B · Post by **Greengem20B** » 01 Aug 2008, 11:25

Imi in the process of having the G200W workshop manual written up in English....

Ill be sure to post it up for all once done