Continued TPS Failures

[SPORT]

Problem: intermittent engine hesitation, cutting out, and stalling while at anything other than acceleration.

Model: 2005 FJR (ABS)

Miles: 30,000

Electrical Mods: PC-3 and Autocom, Barbarian mod

Mechanical mods: Airbox mod

Corrective actions: Replaced plugs, clipped plug wire ends, synched throttle bodies, cleaned ECU plug (was/is not corroded), returned CO levels to stock (de-Barbian modded), replaced battery, replaced airbox cone, replaced TPS...twice now.

I have gone through 2 TPS's and the third has begun to fail. Dealer does not know what to do. Called Yamaha's customer service...again. End result is that PC-3 may be the culprit. He explained that they have seen on some warriors the PC-3 causing excessive resistant, leading to excessive heat in wiring leading to pre-matue failure of the wires leading to the TPS. This would only happen if the PC-3 was spliced into the harness at a point that effects the TPS. However, my PC-3 is attached to a separate bus bar leading directly to the battery.

Another thought is that the ignition switch has begun to fail leading to the TPS failure. :dntknw:

Anybody here experience anything similar?

 

[ionbeam]

Problem: intermittent engine hesitation, cutting out, and stalling while at anything other than acceleration.

Corrective actions: Replaced plugs, clipped plug wire ends, synched throttle bodies, cleaned ECU plug (was/is not corroded), returned CO levels to stock (de-Barbian modded), replaced battery, replaced airbox cone, replaced TPS...twice now.

I have gone through 2 TPS's and the third has begun to fail. Dealer does not know what to do. Called Yamaha's customer service...again. End result is that PC-3 may be the culprit. He explained that they have seen on some warriors the PC-3 causing excessive resistant, leading to excessive heat in wiring leading to pre-matue failure of the wires leading to the TPS. This would only happen if the PC-3 was spliced into the harness at a point that effects the TPS. However, my PC-3 is attached to a separate bus bar leading directly to the battery.

 

Another thought is that the ignition switch has begun to fail leading to the TPS failure.

Did the new TPS clearly fix the problems? Is the air box now back to stock?

I sprayed the dealers words with ******** detector and they immediately turned brown and smelled. After examining the words closer they turn out to be 100% through and through ********.

I need confirmation that the two new TPS clearly fixed your problem. Does this happen from first cold start to fully warmed up or does this happen only after the engine is fully up to running temperature with the thermostat open? The TPS typically fails so that there is driveability problems in very narrow rpm bands and the engine will run fine outside these rpm bands. The driveability issue will be at the same rpm band regardless of gear or engine load.

Do you have a DMM and know how to use it? With a DMM we can absolutely determine if the problem is the TPS. You can check the TPS via the diAG screen but it is not a conclusive test.

Do consider unplugging the PC-3 and reconnecting the stock injector connectors again. PC-3s have been known to fail and sometimes a PC-3 will loose mapping. This is way more likely than a third TPS going bad.

 

[SkooterG]

Yeah, you would be the ONLY guy out there to run through three TPSs in only 30,000 miles. I ain't buying it.

My first 'bad' one lasted 90,000 miles, and the replacement was still fine after 200,000 more miles. And I had a PC3 installed that entire time.

 

[SPORT]

Did the new TPS clearly fix the problems? Is the air box now back to stock?

I sprayed the dealers words with ******** detector and they immediately turned brown and smelled. After examining the words closer they turn out to be 100% through and through ********.

I need confirmation that the two new TPS clearly fixed your problem. Does this happen from first cold start to fully warmed up or does this happen only after the engine is fully up to running temperature with the thermostat open? The TPS typically fails so that there is driveability problems in very narrow rpm bands and the engine will run fine outside these rpm bands. The driveability issue will be at the same rpm band regardless of gear or engine load.

Do you have a DMM and know how to use it? With a DMM we can absolutely determine if the problem is the TPS. You can check the TPS via the diAG screen but it is not a conclusive test.

Do consider unplugging the PC-3 and reconnecting the stock injector connectors again. PC-3s have been known to fail and sometimes a PC-3 will loose mapping. This is way more likely than a third TPS going bad.

1) Yes, the 2 new TPS clearly fixed the problem...for about 4 months. However, The second time it was replaced the error code (15) and amber light shown for about 10 seconds 1 week after getting it back; then no problems for the next 2500 miles.

2) 2,500 mile after replacing the TPS, I almost cancelled a road trip due to not being able to start it. Error 15 and yellow light. Persistance got it started and I didn't have a problem the entire 350 miles. Overnighted in Bufollo and the next morning started up without a problem. On the way home; however, it began to studder while cruising in the twisties, then about 5 minutes later, stalled completely when slowing down to turn right. The remander of the trip was frought with intermittent 3 cylinder running for 20 seconds at a time. Problem subsided the last 100 miles. Stopped by dealer to explain problem, left then stopped by a friends. I didn't even shut the engine off, but turned around in their driveway and went to pull away while in a slight turn. engine stalled and I ended up dropping bike. :angry:

Now each time I start the bike I get Error 15 and the idle is rough and sometimes will die. After it warms up, and while still in garage, it smooths out.

Although the PC-3 has been on, I had the O2 sensor connected for the last 5,000+ miles. I only disconnected the 02 sensor the morning I couldn't get it started.

I have a DMM (I was an A&P mechanic for 10 years prior to teaching) and have tested both TPS's; yes, they have failed. the question I have is what causes them to fail.

As for the airbox, the right side is cut out just inside the air filter mating surface. I have a completely stock airbox and will replace it if needed. The irony here is that NOBODY ELSE who has modified their airbox has experienced this problem.

Based on your insights Ionbeam, I think I'll remove the PC-3 altogether; however, I think the damage to the TPS is already done.

 

[ionbeam]

Just a quick response. Do remove the PC-3 to confirm that it is unrelated to the driveability problem.

The PC-3 should be 100% independent of the TPS in all ways unless someone were to have tapped the TPS wires for power or ground. The TPS wires should NEVER be tapped for anything because it is an isolated 5 VDC reference circuit coming from the ECU.

Take a look at the anatomy of the TPS, it is just a simple potentiometer. There is nothing that that should electrically kill it. There is nothing mechanical that should harm it. The early TPS had issues with the durability of the resistor material causing erroneous readings to the ECU in very narrow rpm bands, regardless of gear. Do your driveability problems happen in a very narrow rpm range? And to repeat my first info request, is it heat related?

The only way I can conceive of TWO bad TPS is that the replacement TPS was not the new design. The only other way I can possibly see is if the throttle shaft was bent causing nutation of the wiper in the TPS.

 

[BlackStar]

The PC3 taps into the center wire or wiper of the TPS. It should be a very high impedance looking into the PC3 as not to load the TPS and change the voltage going to the PC3 and the stock ECU. There is not enough current involved to cause wiring heating. I usually don't use the cheesy tap connector that dynojet sends.

I'd be inclined to connect a DVM to the TPS wiper, check the +5V ref on the high side, and analog ground on the low side and see what is going on. I'd also be looking to failure analyze the failed TPS's to see if its a mechanical issue or an electrical issue (i.e. burnt, which would be wierd). Its possible you have a short in your wiring either to ground, to to 12V backfeeding the TPS. IIRC that same 5Vref is used for the other engine sensors as well. Obviously you would want to check this during the malfunction. Make sure your connectors are not corroded.

 

[wfooshee]

???????

Cheezy tap connectors? I find the connectors in the harness for my PC3 to be first-rate, at least as well-made as the Yamaha harness connectors they intercept everything from.

The rest of your post makes sense, though. That wiper line doesn't go anywhere else, but the other connectors are shared with other sensors, namely the intake air pressure sensor, the cylinder ID sensor, and the O2 sensor. I'm not saying the PC3 uses those, I'm saying the connectors those pass through are the connectors the PC3 taps into.

 

[BlackStar]

Sorry, I was refering to the cheezy tap connector (singular) that taps into the TPS wire on my other bikes. I see that the FJR picks this signal up through the main injector connector so we don't have to deal with that. I dont have any issue with the injector connectors. I'd still be putting a DVM on the TPS Vref, signal, and ground and cracking open a failed TPS to see whats going on inside.

 

[SPORT]

UPDATE:

So I removed the PC-3 completely. After about 150 miles, I've had NO error codes or engine lights.

Guess the TPS problem was coming from the PC-3. At this point, I'm unsure if there is any damage to the TPS, it seems to be running as it should...albeit not as smooth as when the PC-3 was installed. But another way needs to be found to eliminate the light bucking while at slower cruising speeds.

Thoughts?

The airbox is also returned to stock. The Barbarian is at +7 from stock, and I think it'll stay there.

I'll synch throttle bodies this week(end) to see if that smooths it out.

Thanks for all the insights.

 

[wfooshee]

I would venture a guess that you have a bad PC3. First I ever heard of one eating a TPS, and there are an awful lot of PC3s out there, including mine.

 

[ionbeam]

A bit of a summary here.

My PC III for a 2004 FJR does not connect to the TPS in any way.

The FJR TPS signal wire goes straight to the ECU.

Your PC III may be bad; it may need a Master Reset; it may have barfed the FI map that is loaded; should have the PC III internal TPS value checked (setting the PC III TPS is in the Advanced Software of the Dynojet computer software).

My PC III did not like having the CO adjusted via the Barbarian mod and ran poorly until I went back to base settings for the CO.

 

[wfooshee]

That's what I thought when I first read Blackstar's first post here, but the TPS wire DOES go through one of the connectors that the PCIII uses, and besides, where does it get throttle position if not by intercepting the TPS wire?

TPS is in the connector noted as E on my schematic, and the other connector used by the PCIII is connector D.

 

[ionbeam]

That's what I thought when I first read Blackstar's first post here, but the TPS wire DOES go through one of the connectors that the PCIII uses, and besides, where does it get throttle position if not by intercepting the TPS wire?

TPS is in the connector noted as E on my schematic, and the other connector used by the PCIII is connector D.

[serve]

Well I confused. My schematic and I agree that the Yellow TPS signal wire goes through sub-harness to main harness connector E, with no other connections or interruptions to the signal wire.

When I hold my PC III in my hand and physically count the connectors, there are 4 of them and a black ground wire. All 4 connectors go to individual fuel injectors which connects through sub-harness D to the main harness and directly to the ECU. No wire in connector D is related to the TPS. Ground for the PC III goes directly to a battery connection.

Clarification: The PC III sets Throttle Position, and this is not the same as TPS. Saying TPS is a misnomer.

The PC III earns its living by intercepting the injector pulses from the ECU and then modifying the duration of the injector pulse by some percentage. To set the PC III "TP" your computer must be connected to the PC III and the Dynojet computer software is running in the Advance mode. From the procedure:

When a Power Commander III is connected to your computer and powered so that the software can recognize it, the "Set Throttle Position" option is available from the "utilities" menu (figure G)

With the throttle in the idle position the PC III can read the pulse width of the fuel injector. You click on the TP Closed button and now the PC III will recognize this pulse width and timing as 0 TP. With the throttle in the WOT position you click on the TP Open button and now the PC III will recognize this pulse width and timing as 100% TP. From the procedure:

The Power Commander has now been set for the full range of your throttle. When the throttle is closed the %Throttle on the Commander Center Monitor should read 0, and when it is all the way open it should read 100

[Return volley...]

 

[wfooshee]

What you just said is what I was looking for when I saw post #6 the first time.

Those four connectors do not go directly to the injectors, though. When you open connectors D and E, you have four halves of those connections. Those four pieces are where the PCIII hooks in. It "Intercepts" the D and E connectors. the actual injector connectors are only two pins, not six (with five in use.)

What you say about setting its throttle position makes sense, but I'm not sure it's not just calibrating the reading of the TPS, as opposed to the injector pulse width and timing. The PCIII learns your TPS in that procedure. Main reason I say this is that I don't see how a certain throttle position would yield the same reading in pulse width or timing under different conditions, such as a different temperature, different gear, different altitude. Pulse timing would give RPM very reliably, but I don't see getting throttle position out of pulse width other than as a "probably." And engineering-wise, why try to calculate something you can see on a wire you're connected to?

The only way to be sure, without calling Dynojet and getting trade secrets, is to pull the yellow wire out of the connectors for connection E and twist them together, so the TPS still feeds the ECU but not the PCIII, and see what happens . . . . Any takers????

Interesting discussion.

 

[SPORT]

So based on Wfooshe and Ionbeam, I'm wondering if I could perform a hard reset and install it again?

Since installing and programming it several years ago, nothing has been done to it. I first tried Wallys smoothness map before settling on a more 'peak performance' oriented map. It ran fine, but gradually deteriorated the TPS.

It sounds like that, IF I try to re-install the PC-3, I should reset it to factory settings first, ride it for several months, then try uploading a map. All the while monitoring how the ECU/TPS react to such changes.

In the end, the goal would be to confirm whether the fault came from the:

1. PC-3 hardware
2. Uploaded MAP
3. Airbox mod or
4. Barbarian Mod

If/when the time is made to diagnose where the problem is, I'll post my findings here.

 

[ionbeam]

...Those four connectors do not go directly to the injectors, though. When you open connectors D and E, you have four halves of those connections. Those four pieces are where the PCIII hooks in. It "Intercepts" the D and E connectors. the actual injector connectors are only two pins, not six (with five in use.)...

So based on Wfooshe and Ionbeam, I'm wondering if I could perform a hard reset and install it again?...It sounds like that, IF I try to re-install the PC-3, I should reset it to factory settings first, ride it for several months, then try uploading a map. All the while monitoring how the ECU/TPS react to such changes...

I wasn't ready to post on this yet but I will note these things. The PC III has four 6 pin connectors with 8 wires in one 6 pin connector, 7 wires in another 6 pin connector and 6 wires in the remaining two connectors. One of the connectors has Yamaha colored wires but the wire colors do not match the location in the connector shell as depicted in the FSM schematic.

The connectors on my PC III are not cheap, the important signal connector's female half is "O" ringed to keep moisture out and all four of the connectors have weather pak insulating plugs around the wires to keep weather out.

Do reset and try the PC III again. Start out with the Zero Map, if the PC III is going to cause a driveability problem you should easily and quickly find it here. After installing the PC III go to the diAG screen and confirm that the TPS reads 15-17 and 97-100. If the PC III is causing a TPS issue the TPS reading will be wrong after plugging the PC III into the harness.

 

[LAF]

ionbeam,

When you say this in the above post "After installing the PC III go to the diAG screen and confirm that the TPS reads 15-17 and 97-100." I have a question, can this be done while a PC III or PC V connected? By that I mean with it plugged into the harness as ready to run? I have never had success getting into my diag screen when the PC V is connected? I will confess I have not tried real hard either. And as a follow up since you manually input TPS numbers in the PC V software for TPS what would you enter for those numbers. I had heard you can calibrate the TPS in the PC V software but I failed at making that work and just put in the numbers that were there when I started.

Thanks for any input.

 

[SPORT]

...Do reset and try the PC III again. Start out with the Zero Map, if the PC III is going to cause a driveability problem you should easily and quickly find it here. After installing the PC III go to the diAG screen and confirm that the TPS reads 15-17 and 97-100. If the PC III is causing a TPS issue the TPS reading will be wrong after plugging the PC III into the harness.

Sounds like what I meant... ;-)

Thanks.

This will be accomplished when I have down time.

 

[SPORT]

Think my PC III just died while connected to USB.

With PC III removed and connected to desk top PC with 9v battery, the LED throttle Position lights showed both High AND low lights, then shut off all together. Tried removing and re-installing battery with no change.

Things that make you go...