Dash2 coolant temp issue

**garef001** · March 29, 2020, 09:57 AM

Hi guys,
I have a 2015 atom. Have an issue with my dash2 not displaying correct coolant temps. I have read up everything I can find and contacted both TMI and race tech. Figured maybe someone here might know something.
Had to pull the motor and when I put it back in the correct coolant temp is not displayed in the dash2. It’s reading 259f. When I connect my flash pro the ecu is reading correct coolant temps. As far as I can see my car only has the one original Honda temp sensor.
Race tech told me that the 259 is because the dash2 is not getting a signal. But when the fan turns on the coolant temp numbers cycle up and down. I think -3000 to 3000.
If I had snagged a wire wouldn’t the fan turning on not affect the temp reading on the dash. Also like I said the ecu via flash pro is getting the correct temp.
Any input would be greatly appreciated

**BobK** · March 31, 2020, 07:39 AM

I had a similar issue with my 2012 K20 and I haven't been back with my car since it happened. It appears Ariel UK added a Land Rover temp sensor on the engine where the coolant hose attaches to the engine. The weird thing is this sensor doesn't sit in coolant! It just screws into a boss and apparently reads air temp. I asked TMI about it and the only answer I ever got was yes the engineers said that was the way it was designed. They sent me a new sensor but I haven't had a chance to install it and see if it works and I never contacted Ariel UK about it. If the new sensor doesn't do it I'm just going to install a standard temp sensor in the coolant hose and run it to a gauge. My temp reading went as high as 450 degrees F which obviously would have shut the engine down so I knew there was a problem with the reading and not the actual temp.

**sector: 4** · March 31, 2020, 04:13 PM

Originally Posted by BobK

I had a similar issue with my 2012 K20 and I haven't been back with my car since it happened. It appears Ariel UK added a Land Rover temp sensor on the engine where the coolant hose attaches to the engine.

The way I read the top post, the reading was fine before the engine came out. It sounds like it might be a loose electrical connector or a bad connection somewhere.

Originally Posted by BobK

The weird thing is this sensor doesn't sit in coolant! It just screws into a boss and apparently reads air temp. I asked TMI about it and the only answer I ever got was yes the engineers said that was the way it was designed.

The sensor should be submerged in coolant. There shoudn't be any air pockets in the system except at the expansion tank. Any high spots where air could be trapped should have manual air bleed screws or very small hoses allowing air to escape to the expansion tank.

**BobK** · April 1, 2020, 06:27 AM

The sensor does not sit in coolant! It sits in a spot that is dry and meant to be that way. If I was where the car is I would take a picture.
I found the photo I took to send to TMI. That plate covers an area that is dry while the engine is running or not engine hot or cold.

**sector: 4** · April 1, 2020, 09:39 AM

Originally Posted by BobK

The sensor does not sit in coolant! It sits in a spot that is dry and meant to be that way. If I was where the car is I would take a picture.
I found the photo I took to send to TMI. That plate covers an area that is dry while the engine is running or not engine hot or cold.

I KNOW it does not sit in coolant. Is the sensor even in the water jacket? Maybe they're not using a fluid temp sensor to measure engine temperature.

**BobK** · April 2, 2020, 07:05 AM

Here is a photo of the sensor which to me appears to be a typical immerse in fluid type sensor.

**sector: 4** · April 2, 2020, 07:54 AM

I don't have a Honda powered Atom, but just looking at the pics it appears to me like it's a typical fluid temp sensor which is meant to be immersed in liquid and it screws into a hole in a cover plate where a hose elbow used to go (maybe for a thermostat), in the water jacket. If so, this area should NOT be dry all the time. If it is, then there's a problem. It could be low on coolant or there's trapped air and my previous comments about bleeding trapped air apply.

**BobK** · April 4, 2020, 07:07 AM

As I said in my first post TMI has confirmed that the sensor sits in a dry hole!

**sector: 4** · April 4, 2020, 01:08 PM

Originally Posted by BobK

As I said in my first post TMI has confirmed that the sensor sits in a dry hole!

I KNOW what they said.

**BobK** · April 7, 2020, 05:28 AM

Originally Posted by sector: 4

I KNOW what they said.

So why are you arguing with me my friend I'm just repeating what they said and you are intimating that either I or they don't know what they are talking about.