More re F90 TPS voltage

[fairdeal]

I have never had to "mess with" the TPS on the 2006 F90 -
although aware from the SM of the "learning function" design
so i followed the recent threads with interest,
particularly the attempts to "interpret" the SM verbiage.

I took some some today to get out YDS and the VOM and do some 'sperimenting.

"As found" at key on - backprobing the TPS output measured 0.909 with the VOM
and hooking up YDS showed almost exactly the same value:



OK - makes sense - the "actual" value was NMT 1.4 -
so the ECU used the "actual" value.

Next, I opened the throttle, to cause the TPS to output 1.547 V -

and then I turned key off.

I was expecting, when I turned it back on,
I would see YDS show 1.4 - while the VOM showed 1.547 -

Nope.
Not only did the ECU display the actual TPS voltage of 1.547
it also correctly indicated that the throttle was open to 21 degrees



So I have no idea what the "learning function" means.

Although here is one more interesting observation:

while I was standing there, staring at the YDS screen -
baffled that the ECU was actually correctly displaying TPS voltage
AND
that the throttle was actually open 21 degrees -

I idly moused over to do a "Stationary Test"
and got this:

[99yam40]

what does NMT stand for?
no manual throttle maybe

Sounds like what Rod was saying in another thread , that fixing the TSP voltage would solve that guys problem with it showing in gear/ running when it was not

I do not remember if his throttle angle was showing off also

I went back and looked
his angle was 5.8 I think
and Rod said "once that code is set it wont update"
did you look to see if there were codes present now?

I am not sure what will not update, but can you tell what will not update on this one until you clear the codes

maybe that message will not go away

[boscoe99]

I think by NMT he is saying Not More Than.

Rod said to fix the TPS value. There is no fix. The computer self learns what the TPS value is when the key is turned on, with the throttle in the idle position.

I get the self learn part. I am thinking that the words I quote from the Service Guide are mishmash from a translation problem.

[99yam40]

OK, but what about when the key is turned on with the throttle not sitting at idle?
is this not what fairdeal did and got the same warning along with voltage and throttle angle being messed up?

we just need to know what will not update if a code is not cleared
could it be the idle TPS voltage?

[boscoe99]

OK, but what about when the key is turned on with the throttle not sitting at idle?
is this not what fairdeal did and got the same warning along with voltage and throttle angle being messed up?

we just need to know what will not update if a code is not cleared
could it be the idle TPS voltage?

The engine cannot normally be started if the throttle is not in the idle position. But yes, it can be overridden. Not sure what the engine would do then. How it would operate that is since it would then be seeing a higher voltage than would otherwise be the situation.

No one here on this forum or at Yamaha USA that knows. Only some obscure engineer at Yamaha Japan perhaps. More than likely it will be at Mitsubishi, the manufacturer of the ECU.

Sad that for the most part if anyone wants to understand an outboard motors electrical system they might have to find stuff related to an automobile, and hope it crosses over to the outboard motor.

[99yam40]

at least fairdeal is checking on somethings.
where did he go to anyway?

He needs to tell us if turning the key on with throttle not at idle caused a code and if it did what cannot be updated without clearing the code.

maybe the F90 he got his hands on now has problems like the original poster on the other thread and the owner has done something bad to fairdeal.

Boscoe, how are the codes cleared?
is YDS needed?

[boscoe99]

Where the hell is fairdeal anyway? Spending too much time at TOS I suspect.

Need him to do some testing. Start the motor in neutral at a fast idle with a high TPS value. What happens? Does it set a code?

Think YDIS is needed to clear the codes.

[boscoe99]

Winter time. It is slow here. Need to get some action going.

[pstephens46]

Where the hell is fairdeal anyway? Spending too much time at TOS I suspect.

Need him to do some testing. Start the motor in neutral at a fast idle with a high TPS value. What happens? Does it set a code?

Think YDIS is needed to clear the codes.

Are you saying (writing) to use the neutral button on shifter, advancing throttle and then starting?

i have used YDIS to clear codes

[fairdeal]

Where the hell is fairdeal anyway?
Need him to do some testing. Start the motor in neutral at a fast idle with a high TPS value. What happens? Does it set a code?

Yes, the limitation to what i was doing yesterday, I didn't start/run the motor;
I need to do that.

with just key on, there were no "codes set" - why would there be?
just that YDIS error message when I had the throttle advanced.

I still don't understand this:




Other than an in-range value for the TPS-
how would the ECM "know" that the throttle is closed?
rpms? MAP value? taking into account what it thinks the IAC valve is doing?

and as to experimenting - how would I construct a "high" TPS value -
other than by opening the throttle?

[rodbolt17]

the TPS is an adjustable voltage. misadjust it and see.
but I am telling you that much over about 3* angle it wont allow you to test functions. as you saw.

[walleye1]

Wasen't there some of these engines that didn't see any voltage to the tps unless the engine was running?

[rodbolt17]

like I have said before, some use a set V,some get a value at key on and learn,some have to be running yet they still learn.
if the learning ECU "sees" an above expected value at start up or key on it defaults to a known value.
at certain throttle angles it will go into a FLOOD clear mode and shut off the injectors.
someplace on the net years ago I read about a home made diagnostic test lamp or wink blinky.

[walleye1]

can you buy a winky blinky from yamaha still?

[boscoe99]

can you buy a winky blinky from yamaha still?

Yes. Yes, you can.