2011 yz450f throttle position sensor

[rpxtreme03]

2011 yz450f tps. is there any other way to set this using the jgr mapping system or setting it based on resistance?

does anybody know the resistance on their bike with a properly set tps?

the book only tells how to set it using the diagnostic tool, but there must be another way, weather it is set based n 5v intput or resistance.

[grayracer513]

Here's the problem: The ECU wants the throttle angle at idle to read between 12-21 degrees. You need to see the readout from the unit in order to do that.

Core resistance varies too much from one TPS to another for anyone else's resistance measurements to be an accurate way to set yours up.

[kawamaha]

... but there must be another way, weather it is set based n 5v intput or resistance.

most brands have 0.60V TPS output with 5V input at idle, but I am not 100% positive on YZ's...

edit: RMZ's have 0.6V (0.58-0.62V)

Edited April 23, 2013 by kawamaha

[rpxtreme03]

honda is about.5 kawis about.65..not sure on yamaha though.

[rpxtreme03]

Here's the problem: The ECU wants the throttle angle at idle to read between 12-21 degrees. You need to see the readout from the unit in order to do that.

Core resistance varies too much from one TPS to another for anyone else's resistance measurements to be an accurate way to set yours up.

the degree is calculated by the diagnostic computer based upon the output voltage. the output voltage comes from the resistance across a 5v input. i believe the resistance u are referring to is the coil resistance which is usually around 5ohms but varies from bike to bike. this could not be used to set the tps.

a tps is nothing more than a potentiometer.

Edited April 17, 2013 by rpxtreme03

[grayracer513]

the degree is calculated by the diagnostic computer based upon the output voltage. the output voltage comes from the resistance across a 5v input. i believe the resistance u are referring to is the coil resistance which is usually around 5ohms but varies from bike to bike. this could not be used to set the tps.

a tps is nothing more than a potentiometer.

Exactly, but it's the individual ECU that interprets the voltage output as an angle, and there can be a good deal of variance. While the voltage range could be used to get you "close", it still isn't as precise as using the readout.

[rpxtreme03]

like most manufactures im sure yamaha just uses a desired range for the output at a 5v input. i dont think the individual ecu would make any difference when calibrating the throttle position as the ecu recognizes a voltage and sends a signal to the diagnostic tool which calibrates your degrees. the gytr tool will tell u a degree too, but it only tells u the degree change from 0% not the degree overall on the tps. not sure that was real clear. either way i am just looking to get it close then we can do the fine tuning from there using the gytr to see degree change.

[BGoyins]

I have two 2011's and I can tell you that visually, the TPS settings are nearly the same. I just received the diagnostic tool and I'll let you know some real numbers when I check the settings. I tend to agree with Gray that the calibration is really a calibration of the TPS and the ECU together as it's a combination of the resistance (TPS), supplied voltage (ECU) and logic circuits (ECU) that determine the "understood" throttle position. Which implies that changing an ECU may require a TPS readjustment? I have the GYTR tuner and it is of no value in setting the initial position of the TPS.

I also noticed that the troubleshooting section of the service manual is looking for ECU TPS readings of 15 to 19 degrees at idle (even though the other part of the manual says 12 to 21 degrees) so I would shoot for the middle of the range.

Anyway, some real measurements would be useful and I'll post those soon.

And then there is always the... doesn't really matter that much part ?

[rpxtreme03]

any chance u can see what u have for the resistance too?

[BGoyins]

You got it. I'll have the resistance values Friday. Unfortunately, I just realized that I also need the "diagnostic tool sub-wire harness' So it'll be a few more days for the other measurements.

In the meantime, here's a picture of one of the bikes TPS position. Both bikes are really close and appear to be set a bit more clockwise than the middle of the adjustment range. Maybe it can at least get you up and running for now.

[rpxtreme03]

that would be great! thanks.

[BGoyins]

OK, so here's what I have so far. One bike was 673 Ohms and the other was 710 Ohms. Because both TPS total coil resistance values were different (4.51K and 4.82K) if you assumed a 5 volt input to both TPS then you get about .746 volts and .737 volts output to the ECU respectively; which is pretty close to each other.

But, until I get the harness and can actually see what TPS position each ECU is set for, and how much voltage is really there, these are still just "close" values. But, I bet if you set yours up for about .74 volts it would be really close.

[rpxtreme03]

awesome! thanks for the info. did you take the actual voltage readings or just calculate that?

[rpxtreme03]

that resistance measurement was coming from the blue input to the yellow output at 0 throttle correct?

[BGoyins]

The resistance was measured, but the voltage values were calculated assuming a 5 volt input (Blue wire).

The Blue to Black/Blue wire is the total coil resistance value. The Yellow to the Black/Blue is the wiper of the pot reference to ground (the lower resistance value). This is the measurement I used.

Still, until I can really measure the voltage to the ECU and what TPS position the ECU is thinks it is, we are just taking an educated guess at the voltage to the ECU. The shop manual specifies 4 to 6 volts to the TPS as acceptable, but I used 5 volts for the calculations. I'm guessing the ECU's don't vary that much in their output voltage, but we'll see.

[rpxtreme03]

set it with an ohm meter to 694. i was shooting for 691 which is center of your readings, but thats nearly impossible to get it that perfect. either way the thing runs great!

[BGoyins]

OK, I have the cables and I've taken some measurements on my two bikes. I think I can make some general statements that should get a TPS set within the proper range (15 to 19 degrees) in a situation where you do not have the diagnostic tool and adapter harness. I won't list all the measurements, but if you have specific questions or want me to take some additional measurements I can do that. Also, my sample group is two bikes so... keep that in mind.

In no particular order:

First method: Eyeballing it. Both bikes have essentially the same amount of degree change (as read on diagnostic tool) when the TPS is full CW to full CCW: 8-25 and 7-23 degrees. Put the TPS half way in the range, maybe just a tad more CCW, and you're probably there. Not a very satisfying way, but seems to work if you don't even have a multimeter.

Second method: Try to get as close to .700 volts to the ECU as you can by adjusting the TPS while the bike is running. Measure from the Yellow wire to the Blue/Black wire on the TPS harness connector. This is, IMO, the best way using a meter. One bike was .710 volts @17degrees and one was .690 volts @17 degrees. The difference in voltage between those two would cause about a 1 degree change on the diagnostic tool.

Last Method: Resistance measurements: The problem with resistance measurements are that the TPS core resistances are different and the ECU supply voltages are slightly different (though both ECU's were almost exactly 5 volts). But by far, the resistance of the TPS is the biggest variable I could see. You can calculate required resistance for a desired .700 volts input, but it's not as simple as I originally assumed. My calculated voltages in post #12 were wrong because I discovered the resistance value of the wiper to Blue/Black drops almost 80 ohms when in the circuit. So, it is not just a simple voltage divider equation. If you have a meter then go for the voltage.

But if you're curious about the "out of circuit" resistance values, one bike was 701 ohms and one was 736 ohms. These values are slightly different from post #12 because those were for a setting of 16 degrees and I changed both bikes to 17 degrees.

Finally, this relationship is true for the TPS: TPS CCW = more resistance=more voltage to ECU=greater TPS degree value.

Hope this helps.