How To: Replace Gear Position Sensor (GPS)

Gear position sensor GPS

For three wire

drgai said:

Thanks for all the info! i have a 2011 Roadster and my GPS recently went totally kaput after being problematic for awhile (showing 6th gear at timed, problematic neutral light...). However, after reading some of the comments, I took the GPS out and it seems different. Instead of the circular contacts (similar to all the part diagrams) I have a unit the has what seems like one central contact and one pin in the periphery that when positioned aligned with the to screw of the GPS, fits into a hole on the transmission. I even bought a used unit that supposedly fits and it looks the same as in the diagrams, fits nicely into the GPS mount, but is completely different than mine, and I doubt that it will work. Both units (mine and the used one), have two wires coming out of it. What am I missing?

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Sounds like the used unit is for 04-09 Rockets, not Roadsters. The part diagrams only seem to show the 04-09 design alright, they didn't update them for the Roadster GPS which has the pin built in and the contacts concealed inside. What I don't get is why the one that came off your bike, apparently has the pin built into it but has only 2 wires..?

History of GPSs in Rockets - bear with me now because this can get a bit complicated;

This GPS here T1190814 is the one you'll find on 04-09 Rocket III / Rocket III Classic / Rocket III Classic Tourer.
There is a rounded pin on a spring that sits into the gear position shaft on the transmission, the pin rotates around and contacts the patches on the GPS face.
The cable is a 2 wire one.

The pin, which has a spring behind it;




This one T1290642 is from Rocket III Roadsters 2010 to March 2013.
The pin is built into it, and the contacts the pin rotates around on are inside in the unit.
The cable is a 3 wire.
It is no longer available from Triumph as it was superseded by the next one far below.


When Triumph fixed the Roadster GPS fault in March 2013, the 3 wire new style GPS above was superseded by a 4 wire GPS that looks the same except has a 4 wire cable on it.


The 4 wire GPS is T1292057 below, which was the final GPS for the Roadster.
This looks similar to the 3 wire one above, i.e. the pin is built into the GPS, but a little difference in the face design, and obviously the amount of wires and the plug top.

N.B. if you have a 2010-2013 Roadster, you also need T1290666 which is an adapter fly lead to connect the GPS to 2010-13 Roadsters, because 2010-2013 main harnesses have the matching 3 pin oval plug as T1290642 above has. But you can buy T1296589, which is a kit that contains T1292057 (final Roadster GPS), T1290666 (adapter fly lead) and T3600267 (o-ring for the GPS) instead of buying separately.

Great information. Thank you.

Was this post ever made into a sticky in the Tech section?

Thank you for this. The clear, logical information has really helped me.

R-III-R Turbo said:

That's the little bugger alright.

That rotten crimp there is where the single purple wire (just above the red circle) joins into the two purple wires that go up to the speedo and tacho. The crimp is about 2' back from the speedo & tacho plugs.

Here is an example of the other crimp, which is about 8" from the fusebox (where the reg/rec plug joins harness), gone rotten;





Diagram to illustrate the purple wire layout in the Roadster harness;

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If you have replaced your GPS and are still getting Nada at startup, after the initial sweep of gauge lights, it is worth considering the "purple wire" issue. I had replaced the GPS, all the fuses, the battery, checked all the relays and the problem persisted. I bought a little diagnostic gadget, got a persistent P1690 code appearing and then found this thread. The problem did indeed turn out to be a 4cm section of corroded purple wire, deep in the body of The Beast, which was preventing the ECU from providing sensor information to the gauges and ignition. As soon as I repaired the damaged section of purple wiring, I was once again rattling the fillings out of my neighbours' teeth.

Rocket__88 said:

If you have replaced your GPS and are still getting Nada at startup, after the initial sweep of gauge lights, it is worth considering the "purple wire" issue. I had replaced the GPS, all the fuses, the battery, checked all the relays and the problem persisted. I bought a little diagnostic gadget, got a persistent P1690 code appearing and then found this thread. The problem did indeed turn out to be a 4cm section of corroded purple wire, deep in the body of The Beast, which was preventing the ECU from providing sensor information to the gauges and ignition. As soon as I repaired the damaged section of purple wiring, I was once again rattling the fillings out of my neighbours' teeth.

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Thanks I made a video on it years ago and guided many captains on identifying & fixing the purple wire problem over the years. It's a different problem than the faulty GPS.

R-III-R Turbo said:

Thanks I made a video on it years ago and guided many captains on identifying & fixing the purple wire problem over the years. It's a different problem than the faulty GPS.

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Yes indeed, but it presents itself in a similar way. Without knowing the specific error code, the more well known possibility was a failure of the GPS. Your information was crucial in saving me many more hours of frustration and head scratching. I thought it was worth adding to the end of this thread, for those who, like me, had already replaced the GPS, checked all the fuses, relays, battery etc and were still left with an attractive two wheeled, immobile paperweight. Thanks again.