Re: Re:[ST] 99 Sprint ST fault codes and Idle or stalling problem.continued

[Frederic.Nizery@xxxxxxxxxx]

Stephen,

what year is your bike? I have only schematics for post 2002. the pin 
numbering seems different
for me. It's more a matrix fashion for me (letters and numbers).

> > First of all, thanks for the help so far, guys.

> >  What I have found is that the throttle position sensor, intake air
> > pressure sensor, intake air temp sensor, engine coolant sensor, and the low
> > fuel sensor share connection 34 on the MC2000 ECM.  The throttle position
> > sensor and the intake air pressure sensor share connection 12 on the  MC2000
> > ECM.

Let's say I trust you here.

> > While checking continuity of the wires I found that there is  1.818 

When you speak about continuity, do you speak about resistance? Is that 1.818 Ohm or kOhm (i.e. *100Ohm)???
Most of the time even the multimeter pin contact introduces some 1 Ohm or more.
Let's put your multimeter on resistance (ohmega symbol) first or second range (0-10k or 10-100k).


> > (a little less than 10%) continuity between 12 and 34, although not near full
> > continuity.  I checked the pins on the throttle positioning sensor and found
> > the same 1.818 continuity on the pins that connect to 12 and 24.  With the
> > connector off of the throttle positioning sensor, checking continuity on the
> > air intake sensor reads zero 

(0 continuity? should I understand infinite resistance).

> >  The continuity of those two pins on the throttle positioning sensor do not
> > change when twisting the throttle. 

Well, it' a simple potentiometer. nothing more nothing less. Let's try a schematic:
   
  !------ + 5 volts
  /
  \
  /<---- position related voltage (between the low voltage and the hight voltage) 
  \
  /
  \
  !------ + .5 volts 

One of the two pins (the one that is not common to other sensors is a floating volage used to ajust
the zero position from the ECU). I instead moved the sensor until having idle regulation (o2 sensor 
voltage going up and down arround 0.45 volts). But I have a O2 sensor (2002 model).


> > I notice in the haynes manual that it
> > takes special equipment to set the throttle positioning sensor if it is
> > removed or replaced.  I also notice that the throttle butterflies do not
> > close 100%, but maybe 99%

If you use Haynes you have a pre 2002, don't you?

> >   I have two questions now.  Should there be almost 10% continuity between
> > two pins of the throttle positioning sensor?  Could that be caused be the
> > throttle positioning sensor being mis-positioned or faulty, or is it
> > supposed to be that way and I need to keep looking for the source of this
> > interesting problem?

You should have a voltage ranging between ~0volts and 5 volts depending on the trottle position.
Remember don't check continuity w/ ECU connected.

> > Stephen

Fred 02 ST BRG


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