What would cause tunerpro to display a coolant temp of -39.99?
Sometimes its in a red font color sometimes it turns blue.
Also, what is Startup Coolant Temp? Why is there two?

Is this while datalogging?


You could have a bad coolant temperature sensor or corroded connections.

Yeah while I had it connected to the car I noticed all this. I noticed it while trying to diagnose primary fan not working.

I disconnected the CTS connector and applied resistance to it with a potentiometer, doing the same thing the CTS should do, while in the ign mode with the key turned but engine not running. The Startup Coolant Temp values would move when we adjusted the resistance to the harness connector, however, once the engine was turned on, the computer would show the last value we had it on and no longer take any input

I assume you’re using $32B code. I use Tuner Pro as well and it does the same thing for me. There are supposed to be two coolant temp setting. One will continuously update and the other will always display the temperature of the engine when it was started. I believe it is a problem with the Tuner Pro Bin Definition file. I believe it is a problem with the data stream file, there is probably a way to modify the file to make this work properly but I don't know how. If anyone else does please speak up.

Your sensor should be fine. I get the correct coolant temp when I use Moates Dos based software. I thing Tuner Pro will also display the coolant temp correctly if you are using $6E code, it seems like I tried that before.

Anyway, if you need to know the correct coolant temp use I'd say use the Moates software unless someone knows how to modify the data stream file.

ahh yes, well moates program has never worked for me, i keep hitting 1, get nothing, i don't know what it's deal is, laptop is win98. but i loaded a 6E datastream and indeed the computer sees a coolant temp. slightly acurate with the dash gauge. i guess i dont know why the primary fan doesnt work since the comp sees a temp and we have switches on the relay that make it work but i guess thats a question for the cooling forum, even though they dont like answering fan questions over there and say search all the time, but search is all stupid now. thanks for the help

I wouldn't recommend using $6E datastream file to datalog if you are running $32B code. It shouldn't hurt anything but you may not get accurate logs if you are going to be tuning, but I could be wrong.

Does anyone else know how to fix the $32B datastream file?

Apply the 6E bin that matches your car. Unplug the cold start injector. Start using the $6E definition.

Okay....Well I like using 32B so is there anyway to fix this problem?