Coolant Temperature Sensor Mystery

[Journeyman]

Has anyone had a coolant temperature sensor go bad on the 2.5s? I was about 10 miles from home when my engine check light came on and a temperature warning. It brought up the temperature gauge and it was pegged all the way to the top (solid red)! I pulled over immediately.

The bike didn't seem overly hot. I checked the coolant level and it was somewhat below the low mark, but not enough, I would think, to cause a problem. There was definitely coolant in the tank. I pulled the seat and checked the fuse for the fan and it was good. I prepared to hitch-hike back home to get my trailer, but thought I'd fire her up again just to see and the temp gauge read normal- too soon to have cooled that quickly.

I rode home and, although the engine light stayed on (normal after throwing a code), the coolant temperature stayed in the normal range. Once there I topped off the coolant and hooked up TuneEcu. It showed P0117 (coolant temperature sensor) and P0704 (clutch switch 1) codes. I cleared both and have since ridden the bike over 100 miles without issue- runs great and not hot.

From what I'm reading about the coolant sensor code- it usually indicates a bad sensor. I'm also wondering, given just how much that POS clutch switch affects seemingly unrelated things (like your gas gauge, for example) if that might not have been the cause. I tinkered with the "tang" on it for the umpteenth time and it's no longer throwing a code. Or, best case scenario, if the coolant being slightly low (maybe a pint or less) was it- but I don't think the bike was ever really overheated.

Now, I'm just a bit paranoid that I'll take a long trip and it will act up again.

p.s. the sensor is located behind the radiator in the thermostat housing (fun to get to). Related information is on pages 876-877, 656-659, and 600 in the manual

 

[biker1059]

Yes, mine went out out on my first ride about 20 miles on the bike. Replaced by the dealer and no problems since. I have a 2020 GT

 

[Kevin frazier]

@Nashvegas had this issue as well, he can chime in on fix.

 

[Nashvegas]

Has anyone had a coolant temperature sensor go bad on the 2.5s? I was about 10 miles from home when my engine check light came on and a temperature warning. It brought up the temperature gauge and it was pegged all the way to the top (solid red)! I pulled over immediately.

The bike didn't seem overly hot. I checked the coolant level and it was somewhat below the low mark, but not enough, I would think, to cause a problem. There was definitely coolant in the tank. I pulled the seat and checked the fuse for the fan and it was good. I prepared to hitch-hike back home to get my trailer, but thought I'd fire her up again just to see and the temp gauge read normal- too soon to have cooled that quickly.

I rode home and, although the engine light stayed on (normal after throwing a code), the coolant temperature stayed in the normal range. Once there I topped off the coolant and hooked up TuneEcu. It showed P0117 (coolant temperature sensor) and P0704 (clutch switch 1) codes. I cleared both and have since ridden the bike over 100 miles without issue- runs great and not hot.

From what I'm reading about the coolant sensor code- it usually indicates a bad sensor. I'm also wondering, given just how much that POS clutch switch affects seemingly unrelated things (like your gas gauge, for example) if that might not have been the cause. I tinkered with the "tang" on it for the umpteenth time and it's no longer throwing a code. Or, best case scenario, if the coolant being slightly low (maybe a pint or less) was it- but I don't think the bike was ever really overheated.

Now, I'm just a bit paranoid that I'll take a long trip and it will act up again.

p.s. the sensor is located behind the radiator in the thermostat housing (fun to get to). Related information is on pages 876-877, 656-659, and 600 in the manual

I chased this exact same thing for months. Totally intermittent. It would be fine on the open road and then you get to a town/traffic and the temperature would start to rise. I used to ride with my temp screen on every time. Usually, if I shut the bike off and let it sit about a minute and restart it I would hear the fans kick on. Might have to do this a couple of times in one sitting. It was very frustrating. Changed out that sensor box and it has never done it again. It was kind of a pain, but really not that bad. Disconnect that top radiator hose and it all tilts forward and you can get to the box. It was tight, but very doable. If you take the whole radiator off, it would be right there.
I bought it from Cross Country Triumph P/N T25077001. $178.80Fan, PWM Controller

No tax outside of Jersey.

 

[Journeyman]

I chased this exact same thing for months. Totally intermittent. It would be fine on the open road and then you get to a town/traffic and the temperature would start to rise. I used to ride with my temp screen on every time. Usually, if I shut the bike off and let it sit about a minute and restart it I would hear the fans kick on. Might have to do this a couple of times in one sitting. It was very frustrating. Changed out that sensor box and it has never done it again. It was kind of a pain, but really not that bad. Disconnect that top radiator hose and it all tilts forward and you can get to the box. It was tight, but very doable. If you take the whole radiator off, it would be right there.
I bought it from Cross Country Triumph P/N T25077001. $178.80Fan, PWM Controller

No tax outside of Jersey.

Nothing like this forum and the people on it to help get you back on the road again, smiling. Thanks @Nashvegas

Were you also getting this same P0117 code? That points to the coolant temperature sensor, but if the fan isn't coming on that makes sense. I may change it and the Fan, PWM Controller.

I looked for the part you listed, but couldn't find it on Hermy's (maybe different year, etc.). This is what I found.....

 

[stingray]

I was finding it as this

Sensor, Water Temperature​

Part Number: T1292114

also needs copper gasket

Washer, Cu, OD 16 x ID 12.5​

Part Number: T355057

 

[Nashvegas]

Nothing like this forum and the people on it to help get you back on the road again, smiling. Thanks @Nashvegas

Were you also getting this same P0117 code? That points to the coolant temperature sensor, but if the fan isn't coming on that makes sense. I may change it and the Fan, PWM Controller.

I looked for the part you listed, but couldn't find it on Hermy's (maybe different year, etc.). This is what I found.....

Yes, 7700.

Nothing like this forum and the people on it to help get you back on the road again, smiling. Thanks @Nashvegas

Were you also getting this same P0117 code? That points to the coolant temperature sensor, but if the fan isn't coming on that makes sense. I may change it and the Fan, PWM Controller.

I looked for the part you listed, but couldn't find it on Hermy's (maybe different year, etc.). This is what I found.....

Yes, part 29. The 7700 is it. Sorry, the extra “1” was how many, one each. I didn’t change my sensor because it was dang sure telling me how hot it was getting and that brain part was saying, “so what? What do you want me to do?“ I think that was the exact same code I was getting, but I will look through my pictures to make sure. I think if you just change part 29 everything will work great.

Edited to add- I was getting code P1552 Cooling Fan.

 

[stingray]

I also found a newer p/n at Hermy's that might have superseded the original, uses the same copper washer.

Sensor, Water Temperature​

Part Number: T1294225

 

[Journeyman]

Yes, 7700.

Yes, part 29. The 7700 is it. Sorry, the extra “1” was how many, one each. I didn’t change my sensor because it was dang sure telling me how hot it was getting and that brain part was saying, “so what? What do you want me to do?“ I think that was the exact same code I was getting, but I will look through my pictures to make sure. I think if you just change part 29 everything will work great.

Edited to add- I was getting code P1552 Cooling Fan.

But I'm wondering, since we were getting different codes, if I should change the coolant temperature sensor, not the Fan, PWM Controller.

My code was P0117 (coolant temperature sensor)
Your code was P1552 (cooling fan)

Did your bike seem like it was actually overheating? I would think so if the fan stopped working. It only happened to me once, so far, but the bike seemed normal, so wondering if I was just getting a false reading from a bad sensor.

 

[Kevin frazier]

When you put it on tune ecu and start bike go to sensor page and watch your coolant temp sensor and when the fan does or not come on. This may show problem.