While driving a very low speeds my engine temperature get up
to 228 to 232. I turn on the a/c to force the cooling fan on. Temp went down. So I went home and let engine idle and temp got to 222. I turned on a/c and then back off fan did not come on. Well at 226 it came on. Went off at 197. When I drive on highway temp runs between 186 and 192. Never overheats at speeds over 20 mph.

Any ideas on this? It drives me crazy. When is the fan supposed to come on? Is it computer controlled or is that module on the fan shroud controlling it. I dont want to buy a fan unit if it computer controled.

Any help would be great.

The fan is controlled by the PCM, which mostly relies on the coolant temperature sensor. A coolant reading exceeding 220* seems a bit high, mine doesn’t exceed 215* even on 115* days. But the pressurized coolant won’t boil at 230* which is the biggest worry. What year is your KL? How many miles? Are you certain that your system is actually full of coolant?




.

It's a 2014. I'm a retired mechanic and the coolant is full. 75,000 miles. No codes, and my scan tool confirms temps to ECM. It's very hard to find schematics online or troubleshooting guide.

When looking at the fan unit there is a module between the power supply and the fan motor itself. I wish I knew what the module does. What's funny is turning on A/C cools it right down fast.

Thank you for responding.

Also some things to think about when adding refrigerant. A good watch here:

I wish I could have been more help. It is very difficult to get much information about current model circuits on most any current vehicle, guess they don’t want to trust non-dealers to do much of anything. Maybe that’s best in most cases since with the computer controls on modern cars most owners will do more harm than good. Perhaps the A/C bypasses the default code and turns on the fans. BTW in Chryslerspeak it’s PCM and TCM.


.