TPS Replacement Woes

[Powerman]

Chasing intermittent issues I thought I would try a TPS. (still working)
The replacement part was 5PS-85885-01-00, now new # 3P6-85885-00-00
Something not working out. I made a before reading of closed 4.375K and open .992K
between the bottom terminal and middle wiper.

Put the new one on and it's not working out? With them on the bench the original is 4.718K and the new one is 2.644K across the resistor . WTF??? They aren't taking it back.

[1911]

Standard policy no returns on electronics. Local dealer purchase? A good dealer parts man would listen to your assertion that you were delivered a defective part, easily demonstrated by asking one of the fellows from the shop to come up to the counter with his meter and service manual.

That kind of customer service is kind of scarce though, isn't it?

I'm curious about what effect the lower resistance has on voltage. About double what it's supposed to be up to 5.0 I guess.

Post on here somewhere about what you are chasing?

[N4HHE]

No return on electronic items because it is so difficult to tell if the returned component is the new or your old. Too difficult to determine if you put it in a broken circuit and blew it too.

Jumper the high (5V) and low leads to the TPS so you can measure voltages in-circuit. If the bike maintains 5V when connected then the lower resistance does not matter, might even help operation in an electrically noisy environment. You should see the same voltage over throttle range on the wiper as with the old TPS. Then jumper the wiper and measure again.

[dcarver]

https://candybuttorg.ipage.com/cba/comm ... omment-882
My readings of 4 different TPS...

[dcarver]

and Ionbeam had this commentary...
viewtopic.php?p=136332#p136332

"One small thing to contribute -- the TPS if just fine with any of the readings you got, statically on the bench. The TPS receives a zero and +5 volt reference voltage from the ECU. Note that zero and ground are not necessarily the same because it is a reference voltage and not a utility voltage like lighting or instruments. The wiper of the TPS will return a 0.7 to 5 VDC to the ECU that is proportional to the throttle position. The ECU does an A/D conversion, then does some math on the voltage to convert the voltage to % of throttle opening. When you see 15 to 17 it indicates the ECU thinks the throttle is 15% to 17% open which it needs in order to idle (the 0.7 volts equals 15% and ≈ 4.8 volts equals 100%). The bottom number will change with idle speed adjuster screw in addition to the turning calibration of the TPS body so there is no real, absolute number. If you want to play, try the idle speed adjuster, this is why you can't get the numbers you want (but don't really need anyway). Turn down the idle speed adjuster and the TPS percentages will drop down. A reading of 101 to 104 indicates the ECU thinks the throttle is 101% to 104% open. The ECU will clip anything over 100%. The range between the bottom number and the upper number is fixed, you can't make the difference larger of smaller, you can only shift the whole thing up and down. Ideally, you would set the idle speed then adjust the TPS. But, as soon as you do a TB sync and then move the idle speed the TPS will be off again. Lots of words to say don't sweat a few % error of the TPS reading.

The TPS is one of several things the ECU looks at to determine the FI shot and ignition timing. As long as the TPS voltage is stable and tracks the throttle the TPS is a minor player in the FI/ignition mapping. If the TPS is non-linear by having drop-outs which exceeds some programmed limit the ECU will react by going into the fuel-cutoff routine. As soon as the TPS passes the damaged portion of the resistor and returns to a normal reading the ECU will have a slight pause (to be sure you really mean the throttle increase) the jumps the FI/timing map back up again. This is the same as abruptly chopping off the throttle then whacking it wide open. It's a rough ride when that happens but it is transient. Importantly, it will happen at the same exact throttle opening, regardless of gear once the engine is warmed up. This is one of the best indications of a TPS failure. My TPS had two drop-out points, one just off idle at around 1,700 RPM and again around 3,000 RPM where it predictably demonstrated the TPS failure."

[Road Runner]

Good stuff, what Alan said.
It doesn't really matter what the Ohms reading is, as long as the voltage coming out and going to to ECM is correct. I think you just check Ohms to look for an open or shorted circuit, and you can see a sweep, but the actual Ohms numbers don't really matter that much. The TPS should be sending a smooth and steady voltage of about .5 to 4.5 volts to ECM. That's what really matters.

[Powerman]

OK so maybe it will be fine. I was just trying to match up the ohms in my science experiment. I'll put the new on on and see what happens with the voltage. Have to set the TPS in my Dynojet Commander, I need the little 9v plug that never came with it?

Next I'm going to clean out the MAP sensor port. Also pull the ECU plug and check for corrosion.

[FJRoss]

Next I'm going to clean out the MAP sensor port. Also pull the ECU plug and check for corrosion.

Check it for sure but that usually throws an error 14.
On the sensor itself, be careful poking around - easy to damage diaphragm inside. Don't use any solvent on it. Blockages are more often found in the hose coming off the sensor - greasy goo in the line. I cleaned mine out with a pipe cleaner and a spritz of carb cleaner (make sure it is 100% evaporated before reassembly).

I'm betting the ECU plug is clean but it is quick and easy to check.

I would make sure the plug wire connections to the boots are good.
Might want to pull the fuel injectors for a clean and check at a specialty shop. dcarver is the guy to ask about this.

[Powerman]

I've had corrosion on the ECU Plug before, haven't been in there for a while.
Also on the Multifunction Relay.

[N4HHE]

The ECU does not measure ohms on the TPS but voltage. The TPS is a voltage divider. Put 5V across it then (assuming it is linear) mid position will be 2.5V. What I suggested was verification of sufficient current for the lower resistance potentiometer.

Potentiometers fail by developing a notch or null position where the wiper no longer makes good contact. If you have problems with a particular throttle position then suspect the TPS. This is made more difficult by drive-by-wire because the TPS is not directly connected to your right hand.

[Powerman]

Threw the TPS in at mid slot. Replaced the bottom fastener with a socket head , fun angle.
MAP sensor was clean and the hose was fine. Put in some new spark plugs, just because I was in there. Fired up.

[Powerman]

Test rode and bike ran great. Was wondering about the DynoJet Commander, I remember putting it on and getting power to it and cranking the throttle open and closed for the TPS. Like I said, set at midpoint and called it good.

Why does a 2013 TPS have 4 pins VS the Gen 2 with 3pins? And WTF is an acceleration sensor on the bottom of the throttle bodies? Don't recall seeing it on the Gen 2, just MAP, ATM press and TPS.

[raYzerman]

Good news!!
4 pin and acceleration sensor are extra inputs required for throttle by wire.

[ionbeam]

About the Gen III TPS