In our last “Diagnosing a Bad TPS” we discovered a faulty throttle position sensor on a 2012 Victory Cross Country. In this article we will cover the steps taken to replace the TPS with a new one. Of course the steps shown here are specific to this model, but, they should be similar on your motorcycle. Anyone that has the skill level to perform the diagnostic steps from the previous article should be able to do this. This repair should not take long, in fact, it’s taken longer to write this article than it took to replace the TPS on our subject Victory.
When the TPS failed on my 2003 Victory it was an easy thing to drive down to my local auto parts store and buy a replacement because it was a common car part.
Sadly, that was not the case with the TPS on the Cross Country, it was made of a material we call “unobtainium,” which is so rare it’s not available to the public, and if it is, only at high cost. What made this replacement TPS unobtainium was that you could not buy it from Victory as a separate part, you had to buy the entire throttle body, and that was in the neighborhood of $350 to $400! Unlike the TPS on my 2003 Victory, this one was not available in the automotive market.
So, there were two options.
Option One: It was pay through the nose for unneeded parts just to get the TPS.
Option Two: Or the “warranty” route could be tried again and have the dealership mechanic “discover” the bad TPS, which after two previous attempts, was unlikely.
If a third option wasn’t available, we would be out of luck and have to take either option one or two, both very undesirable.
I did what I normally do in situations like this is start a search campaign on Google, I knew somebody made this thing, all I had to do is find them. It took me two days of searching to drill down and find the manufacturer, CTS® Automotive Products. There was a reason I could not find this item in the automotive sector, it’s not car parts. This TPS is their “500” series, made for engines used in motorcycles, ATVs, snowmobiles, watercraft, and other similar applications. I called the company and found them to be very helpful, much of the technical information about TPS failure used in my pervious article came from this source. Before you get all excited and try to buy a throttle position sensor from CTS, they don’t sell them, at least not to the end user, they are the guys, that sell to the folks, that sell to the people, who sell to us. Unless you want to buy several hundred of these things, they’re not your guys.
Out of luck again? No, not necessarily, as I mentioned earlier, they were very helpful, and they wanted that failed TPS back, because to quote them, “Those never fail that quickly.” In the interest of helping me, and getting the TPS back for quality analysis, they sent me to one of their customers, Walker Products. Don’t get excited just yet, you can’t buy from Walker either, they are the folks, that sell to the people, who sell to us. But, there is light at the end of this tunnel, at Walker I spoke with their TPS expert who told me they had a program they were working on called “Othermotive® Products,” parts for motorcycles, ATVs, snowmobiles, watercraft, etc., and they were just starting to deal with TPS replacements for motorcycles. He offered me a TPS for free if I would only take a few pictures as I did the job and tell them how it went. I had to think about it for a while, at least two or three seconds before saying yes.
Editors Note: Actually, it was more like hell yes! WITH a happy dance, but only in my mind.
They shipped the TPS out immediately, and two days later I had unobtainium in my hot little hand.
Now that I had the TPS I could move forward, but this wasn’t going to be a simple parts swap like it was with my V92 C. If your TPS has a slotted screw hole like above, there are extra steps you will need to take to get it right. The reason it has a slot is so the starting voltage at fully closed throttle can be set. If you have a TPS with two fixed holes, no slots, there is no adjustment needed, just buy it, take the old one off, and slap the new one on.
It seems I am constantly trying to figure out how to do something that requires a special tool, gadget, or software, and replacing this throttle position sensor was no different. In the Victory service manual they don’t directly tell you how to replace the TPS, instead they tell you how to remove the throttle body. I know, doesn’t seem to make sense, right? It does when you understand that the throttle body is removed from the right hand side of the bike, and the TPS, which just happens be taller than the throttle body is attached to it on the left. To remove the throttle body the TPS has to be removed first. But, you can’t just take the TPS off, voltage readings must be made to ensure it is returned to the same position to keep it’s calibration.
Removing the bad TPS, replacing it with the new one, and keeping the calibration would require some thought and ingenuity. In the manual Victory describes the steps, all can be done with simple hand tools except for one, taking the voltage reading. You are supposed to hook a computer up to the diagnostic port, then open your Victory “Digital Wrench” software and…… Oh, wait, the Digital Wrench is a “dealer only” item, something not available to us. Victory wants to make sure you have to go back to your dealer and pay $100 per hour or more for a service you could do yourself. I’m sure they are not alone in using this tactic, so if you have another brand, what we will be doing next might help you.
For This Job You Will Need:
- A service manual for your make and model motorcycle. (Print or PDF)
- A good digital multimeter.
- A Micro-Scale test lead kit.
- Dielectric Grease
I will be the first one to admit, I don’t know everything. In some cases I’m chewing my way through a problem just like you would, having failures and successes along the way. If I don’t know something I research on line, or try to find an expert on the subject. I knew that the voltage had to make it’s way back to the ECM so that the software could read it, but where to take the reading from? Fortunately the Walker Products TPS expert had advice on a possible solution, take a reading directly by “back probing” the connector on the TPS, but before that could happen I had to get access to the TPS and connector. Time to remove some parts.
The Victory TPS is buried under the gas tank, a bunch of wires, coil pack, and ignition switch. It takes some work to get to, but not much. The gas tank didn’t need to come off, just the rear lifted up some, but removing it made photographs easier. The only parts truly blocking access to the TPS is the coil pack/ignition switch combo, and that’s just four bolts removed. The whole unit can be supported by a bungee cord, to relieve any stress placed on the connections.
Once it’s down and out of the way, you have access to the TPS connector.
To disconnect, the connector has a tab that pushes in, it’s a little stiff, so it will take some effort.
The back of the connector is where the “back probing” will be done.
The idea with back probing is to take your multimeter leads and push them past the weather pack seals to make contact inside. You have three connection points inside a TPS, the reference voltage, signal voltage, and ground, we want to test between the signal voltage and ground while the circuit is energized. (key on) The next thing to do was figure out which wires to probe, this is where a service manual provides priceless information. The wires on a motorcycle wiring harness are color coded, so it was a simple thing to look at the wiring diagram in the manual and determine what wire connections to probe. The signal voltage was the orange/yellow wire, and the ground wire brown/dark blue. This could possibly be different on your make/model, so check your service manual to locate the correct wires.
The first step in the test procedure is to select the thinnest probes from your Micro Scale test lead kit and carefully insert them into the back side of the connector. I chose to have the connector disconnected so I could see clearly to insert the probes. To help them push past the weather pack seals and minimize any damage, I gave them a light coat of dielectric grease. Once the probes were in I put the connector back on the TPS. The next step is to energize the circuit, (key on) twist the throttle, and observe the multimeter to see if you have a rising signal voltage. If you have that, then you can take your signal voltage reading with the throttle fully closed.
And I got nothing, no voltage, the probes were fully in, and moving them around a little still didn’t make contact. I tried holding my tongue different and wiggling the probes, but I wasn’t making contact, it was obvious, I needed to try something else. This was a minor setback, it just required some thinking. I thought about using pieces of copper wire, but any copper wire I used small enough to slip past the seals was not going to be stiff enough, and anything stiff enough would be too large. What to use? It took a bit of thinking out of the box and using something never intended as an electrical probe, sewing needles. Yes, I did say sewing needles, they will conduct electricity, and the needle’s taper would help them slip past the seals. Worth a shot, so I popped over to Walmart and splurged on a $1.85 pack of sewing needles. It worked like a charm, I picked two the same size, greased them up, and they slipped right in. I used the small gator clips from my lead kit to connect them to the multimeter.
Key on, twist the throttle, and we have voltage! I know this seems a little unorthodox, but sometimes things you would not think of as tools can be tools. Now I could move on to taking the base signal voltage with the throttle fully closed. I checked this more than once, opening and closing the throttle to make sure it returned to the same reading, which was 0.894 volts. Write your reading down, do not rely on memory. In some of the videos I viewed I saw several references to realigning the paint marks placed on the throttle body and TPS by manufacturers to maintain calibration when putting a TPS back in place. And just how is that going to work with a new TPS with no paint on it? Right, not at all, this is the most accurate method. Even if you do have a good TPS with paint marks, the slightest bit of being out of position will throw the voltage off and possibly cause an error code in the ECM. After the reading was taken I turned the ignition key off and disconnected the gator clips but left the pins in place and removed the connector from the TPS.
Time to remove the old TPS….. Oops! Another hurdle to overcome, the retaining screw is a Torx “security” head fastener.
This wasn’t really a hurdle, I was ready for it, the Victory service manual had mentioned this, and even gave the bit size. (this is why we get a manual) In some of the videos the guys were coming up against the same thing and trying all the wrong method to deal with the problem. Instead of going out and buying a bit set, which costs less $20, they were trying to drill out the little center pin, or cutting a slot in the head for a flat blade screwdriver. Don’t waste your time trying any of these, just get up off your ass and go buy the correct tools.
Using the correct bit on screwdriver type drive I was able to remove the screw without too much trouble. It was a little tight at first, but with a firm grip, and a good twist, it was out.
After I pulled the old TPS out, it was time to put the new one in. But first I wanted to take a moment and take in the beauty of the new TPS……
This particular TPS has an internal spring so it has to be inserted on the throttle body shaft, then turned to wind it up. Depending on the make of your motorcycle, you may or may not have a spring, the TPS I replaced on the V92 C did not have a spring. If you pay attention as you are removing the old TPS you will notice the direction you will need to turn to wind the new one up. It took less than five minutes to have the new TPS in place, connected, the clips back on, and the multimeter ready to go.
The next step is to restore the correct calibration to the new TPS. Start with having the Torx screw tight enough to hold the TPS in place, but a little loose so the TPS can be rotated. With all the leads in place and the multimeter on, turn the ignition key on to energize the circuit. Rotate the TPS slowly and watch the multimeter readout to determine which way to rotate to get the desired signal voltage. When you are there tighten the screw down and keep your eye on the multimeter reading. Don’t be surprised if you see the read out change when you are at fully tight, it happened to me too. More than once actually, even trying to hold the TPS in place didn’t help completely. What I ended up doing was setting my voltage at one point, knowing that at full tight it would end up at the correct voltage of 0.894. A little trial and error and it was done.
Editor’s Note: When you are tightening the screw, use the same handle you used to remove it. Pay attention to the metal you are screwing into, don’t “gorilla” it tight, with soft metals like brass and aluminum you run the risk of stripping the internal threads, so be careful.
Once the voltage was set I opened and closed the throttle a few times and observed the voltage just to make sure didn’t change. I even went full throttle then let it slam shut, it stayed the same, TPS replacement done, key off. All that was left to do, remove the probes (needles) and start putting parts back on.
How long buttoning things up will depend on your make/model, with this Victory, it wasn’t that long, if you have a lot of bodywork it could take a while. If you remove your gas tank make sure your fuel lines are reconnected properly, if you have quick disconnects like this Victory, make sure they have fully “clicked” in place. Also, if you are working on a early model Victory Cross Roads/ Cross Country, the quick disconnect nipple on the tank is very fragile and easily broken. If you are just lifting the tank, it might be a good idea to make sure you are not putting the nipple under any stress in that position. I have heard fragile quick disconnects are a problem with other makes as well, so go easy on your fittings just as a precaution.
If you spent a lot of time (like I did) with the key on, you will have most likely have run your battery down some. Before attempting a start I put the bike on a battery tender for a few hours to build it back up. If you do not have a battery tender for charging don’t expect an enthusiastic spin from the starter when you hit the button.
Diagnosing and replacing a bad TPS is a job that any reasonably skilled home mechanic with the right tools should be able to do. If I had to do this job over again it would take about an hour, two at the most, provided I had the part. This project required some thinking and ingenuity to work around not having the Victory “Digital Wrench” software and lack of longer probes. This is something you might be faced with, or something similar, and you will have to come up with your own solutions. If you read and understand your manual you should be able work out the best way to overcome most obstacles.
The CTS® Automotive Products 500 series throttle position sensor (They call it a “Single Ear Rotary Position Sensor,” no wonder it was hard to find!) comes in more configurations than just what is pictured in this article. It is available in two rotation directions, clockwise, counter clockwise and three different “ear” angles. They are also color coded in regards to rotation, a black cover is clockwise, the grey, counter clockwise. It is my understanding these are used in addition to Victory, on some KTM and Kawasaki motorcycles. There are undoubtedly others I’m not aware of so don’t be surprised if you find one of these on your motorcycle. There are others of course who supply EFI components to motorcycle manufacturers. Some parts will be available outside the normal dealership channels, some not. At least with the knowledge you now have, even if you had to buy an OEM part, you could do the work yourself.
As mentioned earlier, Walker Products, supplier of the CTS® 500 series TPS for this article does not sell this item at this time, but may soon through their program “Othermotive® Products” then they will be available your local automotive parts house. I am grateful for the TPS they supplied and the technical advice provided by their TPS expert. Without Walker’s assistance, none of this would have been possible.
Editor’s Note: You can now buy this TPS on line at Noemtz Designz.
Words By: Terry Cavender
Images By: Terry Cavender
Technical Information Provided By: CTS® Automotive Products
Technical Assistance and TPS Supplied By: Walker Products