Yamaha TPS - Throttle Position Sensor

Yamaha's TPS - Throttle Position Sensor - is one of those topics that you never heard about, until it leaves you high and dry by the side of the road with no way to fix it and no idea of what it may be.

With that in mind, Yamaha a few years ago made a recall for all the defective TPS serial number ranges, but not everyone got to know about that, and many different models of Yamaha's that use those defective TPS's are still out there.

But let's start in the beginning, what is the TPS, what does it do, and why should you worry.

In a nutshell, the TPS is a small sensor that sits on the right side of the XT660R - may differ on other models - and will tell your injection system how much of throttle you are giving, and on its way, will adjust how much fuel it needs to deliver. Once it gets defective, the bike will start to stall, usually when pulling the clutch to start driving, and once the problem gets worst, it will stall even while driving.

So what can you do?

First of all, click on the following link, it will determine if your bike is within the brands recall - http://www.vosa.gov.uk/vosa/apps/recalls/default.asp

Secondly, you should check your TPS itself, and guarantee that it is not one of the ones that sit within the serial numbers that are defective.

For that, you may need to remove the TPS in order to read it. On the side you whould be able to read the following numbers:

All TPS's bellow 46 will be withing the faulty range. That will include the A1 and A2 type. A1 and A2 is another kind of marking you may find on your TPS.

New bikes, above 2009 on the XT's case, will come with the new model, that is phisicaly different than the old one. You can also diferenciate them like that.

The old on the left, the new one on the right:

Another thing you can and should do, is to verify on your bikes diagnostics - the XT660R/X have a built in one, other models may not - and verify that the TPS is within values. Keep in mind that the TPS may be faulty and not present a fault on the diagnostics.

You can learn how to do that on the video we created for that purpose - https://youtu.be/EsCAX45CbOI

If you have an old model TPS, regardless if it is working or not, I strongly advise you to replace it, and even if after reading this and seeing the video you are unclear if your TPS should be replaced or not, please visite your Yamaha dealer and ask around. What is important is that you learned something new, and the next time your bike acts up, remeber that the TPS may be to blame.