Hi, anybody have this message on their DIC?
Last fall I started getting a message that said "low coolant". I have an LS9 ZR1. My coolant was fine in my engine reservoir and in my intercooler. Fast forward to this Spring and the car has been out for a couple of weeks and suddenly I try and start it and it turns over too many times but starts, thought that was weird, but I carry on. Then at a stop light I hear this noise, sounds like my fans running, (never really hear them too often), I look at my DIC and it says "hot engine, A/C shut down". My temp gauge is reading 0. I get it home and it didn't seem to be overheating at all. I Googled and searched, saw some guys with the same problem, but all I have learned is, none of the vehicles were overheating. Anybody have some clues?
TIA.

Or even if anybody has any clues on the "low coolant" message. These could be related or not.

 

Likely a bad temp sensor, seems to be somewhat common if you search around for "Low Coolant Level". I know yours is Coolant Temp but the computer uses uses the coolant temp to calculate the level. Here's just one to give an idea. Note the suggestion to switch the DIC to coolant temp to see what happens:

 

Thanks Rick, I was going to change the display to the water temp, but I was to in a rush to get it home away from the traffic l. I will take it out again and when it does it, switch it over and see what it is saying. Maybe my two problems are in fact related.
Thanks again.

 

I got the Engine Hot A/C Off message when my fan plug melted on my 2008. Doesn't sound like your problem if you hear the fans on but it might not hurt to check.

 

Had the same problem happen to me last weekend. Following a cam/heads/headers job, my '07 Z06 had less than 100 miles on the build and the problem surfaced. My builder read the OBD and it indicated a bad engine temperature sensor. Sensor replaced; codes cleared; back to normal.

Thanks to Josh at HorsePower Addicts in Delaware.

 

Had the same thing happen in my wife's XLR-V one afternoon when we were coming home. Temp read 0 and it advised me to turn off the AC due to a hot engine.

I didn't smell anything or see anything, but I ran the heat on high just in case until I could pull off and get into a parking lot. Hoses weren't hot and coolant was full....so I just called it a fluke. Happened once more a couple weeks later, but never again after that.

 

I get the same "Hot engine, A/C off" message and the DIC will show "XXX" for coolant temp and the needle is pegged at 0 when I dont let the car fully warm-up before driving.

I've been battling this for almost 2yrs now but only in the colder months. I've replaced the coolant sensor (driver side at front of head behind the alternator) twice and the problem still comes back so I've crossed that off the list. Fluid has been flushed (block and all) three times and that never solved anything.

What I have learned/realized is that the PCM has a timer for the coolant to reach normal operating temp. What that exact temp is I'm not 100% certain but seems to be 160*F. If I hop in the car in the dead of a cold morning (below freezing or close to it) and dont let the car idle to warm up I'll get this message within a few miles. If I let the car idle in the garage thereby reaching 160*F before pulling out of my driveway all is fine EVERYTIME.

What I'm thinking is that the cooling system (mine has been upgraded) is too efficient and it hinders the warm-up time in cold weather. This can be similar to the situation the C6Z guys have always had with their oil due to the large oil cooler at the front of the radiator.

Letting my car idle in the garage gives it no air across the coolers to "cool" or slow down the warm-up process.

Like I said, I've been dealing with this for almost 2yrs now and just letting the car fully warm-up eliminates "my" issue.

No way to say this is your problem as well but seems we have similar symptoms and given your geographical location it very well could be yours as well.

 

Mine does the same thing occasionally. I was leaning toward the temp sensor being bad because it was doing it in the middle of the summer last year. (last time I drove it)

 

Thanks for the responses guys. I disconnected the battery and the next morning, reconnected it and then set my DIC to "water temp" to see if it will give me the xxx. So far three drives, engine up to full temp in stop and go driving. No "low coolant level" message nor no "hot engine, AC shut down" message. So I am still confused.

 

Shouldn't the thermostat take care of that?

On our C5, I had an oversize radiator installed and got a Check Engine light, the dealership said it was because the car wasn't warming up properly and it must be because of my big radiator. I told them it must be the thermostat, and change it; if that solved the problem then it's a warranty repair and if not then I owe them for the new thermostat and installation.

New thermostat cured the problem.

 

Your temp sensor is bad or unplugged. Look at the left side (drivers side) cylinder head. The sensor is located toward the front of the car just over the exhaust manifold.

Tom

 

Hi Tom, I don't know if it is, not sure you saw my recent post up above, but after disconnecting the battery everything works fine...SO FAR.

 

I agree. The sensor is either bad or NOT. It won't come back to life once it fails. That is unless the sensor probe is dirty or corroded. Something to think about.

Tom

 

RACER-

Literally just had this happen a week ago after the cam install. Replaced the sensor and still nothing. Found out one of the "very tiny" wires that goes into the sensor pulled apart in the loom. Trace the wire. It's small.

 

Happened to me just now on an 07 z51. No code. No msg. But no a/c either. A/C Just shut off and thats it. Wont go back on. So I guess ill change the temp sensor. Its on the driver side by the manifold?