SmokeyD

Have an message on dic to turn off ac engine running hot. Temperature guage at 0. Also got a message to add coolant, coolant level is about an inch below expansion tank. Infared pyrometer on coolant hoses 195 degrees. Turn car off and let set for an hour re fired car coolant guage works temp 195. Take the car for a spin and hammer it thru 3rd gear coolant guage stops working and get the same messages. Im thinking a coolant sensor?

tim414

Have you done any work or added mods...? What year?

VetteVinnie

I had that problem. It's tuning related if you have a 160 degree thermostat. Coolant temp doesn't get up to operating temperature quick enough, and you need to compensate in the tune so it doesn't trigger this.

SmokeyD

2006 kateck cam kooks headers kn cai.
Car has been running good except a little cam surge.
I had just changed out oem plugs for ngk tr6.
Could it be the colder plug?

jedblanks

Not likely your problem, but keep in mind that the coolant sensor only senses water temp, so if you have air in the system or or some other reason the coolant sensor isn't touching the water, it will read zero. Usually only happens if you are completely out of coolant.

Sounds like your problem is in the tune.

Z.06

Mine was working fine yesterday and started out OK today, but 4 or 5 miles from home I got the coolant temperature XXX message on the DIC and the gauge went to the bottom peg. Then I got the massage not to operate the AC due to excessive coolant temperature. Originally I though the radiator fan plug had melted, a know failure mode, the checking showed that the fan was still operating and the radiator did not seem overly hot.

I tried jiggling the coolant temperature sender wiring but this did not have any result. I think it is the coolant temperature sender itself. The male wiring plug does not want to disconnect. I will try it again tonight.

I think my cheap-o Chinese made Sears VOM is on the fritz, and I will have to buy another tomorrow.

How do I burp the air out of the head after I replace the temperature sender?

v8sten

EViL427 nailed it right on the head, your car should be throwing a DTC. On your DIC go to the Water Temp and it should read "XXX". for now go to any autopart store and clear the code and it will work fine. take it to your tuner and he should be able to see it in the DTC History and desensitize it so it wont come back on.

Z.06

v8sten,
I know EViL427 and Jedblanks both. While my impression is that I am seeing an ECT failure or a transmitter wiring conductivity issue, I am more than happy to accept their suggestion to check for codes and erase codes first in hopes the problem will be fixed by ECM reprogramming. As a matter of fact, this hope was the reason I put my issue out there.

So this is my next course of action. Of potential interest for the CF participants, the 160 degree tstat was installed 2.5 years ago at the same time as my cam and initial tune (by Lethal LLC in Lafayette). My ECM is currently on its third aftermarket tune, which was performed by 510 Racing in Tomball. My initial impression was that the 510 Racing tune was perfect. Since that tune, I have seen very few rough edges that could be improved by tuning. I have also been through 2 winters, which I would have expected to expose the type of problem that I am having now. Let's see where this goes.

Z.06

This is confirmed as a tuning issue. When I started the car this morning, the Engine Coolant Temperature is "XXX" was still there. Since I knew the engine was not hot, I drove it a short way. The first temperature I remember seeing was 165 degF. I still took it to an autoparts store and a code had been lodged. So it looks like my tune needs a minor modification.

I am still surprised to have only seen this message once in the two years since the 160 deg thermostat and tune was installed. Just glad to understand the issue.

VetteVinnie

You're seeing it now because it's cold outside.

blkbrd69

True;
The car looks for a coolant warm up rate. A 165 thermostat and no tune have thrown this with 3 cars before I tuned them.

Can be cleared by disconnecting battery but will just keep coming back till changed in tune.

redrocketship

My car is having this issue and it does have a 160 thermostat. Can anyone tell me where in HPtuners I need to look to change this? Thanks!