This morning as I was sitting and waiting for a parking spot. I got the following error message "cooling system on"

 

I would assume you're asking what could be wrong?
1st thing. More info is needed. Always state year of car, engine etc. Also any previous problems or repairs that could be related to this. As much info as possible usually helps.
As far as your problem. What was the engine temperature at the time of the message? Sounds as if the temperature got high enough to trigger the message that the car had a problem.
Did you check the coolant level? You should have, and if so, where was it at?

Without some more info, it would be hard to make an internet diagnosis. If you aren't familiar with the operation of your car, your best bet would be to take it to a dealer or repair facility.

 

to the forum tamster!

I think you meant "Cooling Mode On" which is a message displayed on the DIC defined by Chevy as.....

"COOLING MODE ON This message may display on some vehicles. Under severe conditions, hot ambient temperatures, steep grades, and towing, your vehicle may experience more transmission shifting. This is temporary and normal under these conditions. This does not require engine or transmission service."

Prolonged idling in high ambient temperatures can trigger this message, but it is always a good idea to check your coolant level if you get this message.

If you continue to get the message, or notice that your vehicle is continuously running hot, have it checked out to avoid engine damage.

 

Hello community of HHR's. When I drive for a hour so stop or slow down my cooling mode goes on. Then when I stop and turn off ignition my fan keeps running. I have a 2010 hhr 2.4 I believe. Another time my temp gauge rises too high 230 or so.

 

That is very bad! Go to a good mechanic right away. Temps above 240F are deadly to the engine. Have you checked your coolant level?

Since you don't know for sure which engine you have I am assuming that you don't have any mechanical knowledge making this a job for professionals. Maybe this is a wrong assumption.

 

to the forum hhrpaul10!

Heed Don's advice A.S.A.P.

These engines absolutely will not tolerate repeated overheating, cracked heads or blown head gaskets will soon have your repair costs zooming into "big bucks" territory.

 

dido^^ my LS 2.2 runs 183F almost all the time.. if i idle it might get close to 190 but never past 191. even under heavy driving it maintains 183F