2005 Chevy Aveo Overheating / No A/C / No Cooling Fan Case Study PT2 Diagnosis, Repair and Retest 

Glad it was helpful! /K&K

Glad you like them! /K&K

Funny enough she has put 70,000 miles on it since this repair. It may seem like we were careless in fact the high speed fan doesn't kick in till 217F so 223F isn't that far off. You can lose low speed operation and still have high speed but there is no way to test the automatic fan controls unless you run it 217 F+. /K&K

Its normal for an engine to heat up after you shut it off. The temp sensor is close to the heater hoses so its possible the temp sensor is see the temp different in the coolant temperature when you run the heater. If its not running hot when on I wouldn't be to concerned about it. Most of the vehicle I have owned over the years do the same thing. /K&K

@@KNKRNR Thanks so much for your reply ❤️

The stalling would be a separate issue. I wouldn't worry about the steam as the radiator got wet which is okay. Those cooling fans and connectors are built to deal with water. The fan issue your having may be the same as the Wave and the Aveo are sister products. If you look down and see the fan motor resistor in bad or cracked shape I would start there. As far as the stalling I would start at the battery cables first and wiggle them around and see if the car stalls again. You would want to duplicate the issue first before replacing any parts. No car should stall at a car wash. /K&K

@@KNKRNR Thanks, I am trying to figure out where the location of the Fan Motor resistor is as it's not super clear to me watching this video. Hoping this is an easy not super expensive fix I need my car too get to work! =)

@@KNKRNR I took my car to my mechanic today and he solved the issue. Was a faulty ground, said it was the cause of all my issues. Car is working great again!

So below 137F coolant temp with A/C on the fan is off. After 137F the fan should cycle on and off when the A/C compressor is cycling. Low speed kicks on at 203f off at 197F High fan speed mode doesn't happen till 215F or when A/C head pressure reaches 240 PSI. They want the engine to run around 200F-210F to peak emissions performance. I would start to worry about the temp after 212F to 220f degrees. I'm not a fan of dual speed systems because the temp swing can be all over the place. /K&K

@@KNKRNR Thank you very much for the response!

Maybe a wrong switch, you have always on and always off type. Confused? I am 🤣

People do bypass the resistor but running cooler will cause the thermostat to cycle more so you might have to replace the thermostats more frequently then normal. /K&K

@@KNKRNR what thermostat will cycle more? The thermostat is rated at 87 celcius, if i bypass the low speed resistor the fan will still kick at 93c and stop at 89c but in high speed rather than low speed , so the thermostat will cycle normally

​@@mohammadaburabee4980 The only reason why GM used a two speed fan was to keep water temp at a controlled level. If you live in a hot climate its no a big deal to run full speed cooling fan, but where we live its a cold climate 8 months out of the year running the fan on high when commanded by the ecu would cause the coolant temp to drop lower then designed thus causing the thermostat to cycle more frequently which wears them out faster. When the thermostat goes out on these engines they run 170f (76C) which is too cold for good fuel economy. Personally I don't like two speed system, but there is a reason why most auto manufacturers are going this route. If you live in a hot climate no problem run it as one speed, but if you live in a colder climate you may want to replace the resistor and run the system in its two speed mode as its designed. /K&K

@@KNKRNR thank you so much for the useful information you shared with me, my other question was when start my ac does the fan kick in high speed immediately or does it start in low speed then switches to high speed at certain point? Lets assume then engine coolant temp was 65 c and i started the ac

Parts costed around $150.00, labor was $150.00. /K&K

2009-2011 Aveo's may have a temp sensor in the radiator that controls the fan cycles. I would start with that sensor in the radiator first. Check out the link below for the sensor you may need. www.rockauto.com/en/moreinfo.php?pk=3405729&cc=1444457&pt=4748&jsn=907 /K&K

@@KNKRNR we are reading temps from the sensors, but still not engaging the fan. We can control the fan through the ECM/PCM with the scanner, but it's like it won't turn it on by itself.

After looking at the control side of the fan system schematic 2009-2011 the temp sensors feed the ECM temp info, then the ECM sends the signal to the High and Low fan relay to trigger the fan. My educated guess would be you might have an issue with the ECM that controls the automatic fan control operations. Its odd to me you can control the fan(s) manually but the automatic fan control circuit does not. /K&K

@@KNKRNR i changed mind and nothing still

I would call your local GM dealership as that's what we had to do. They need your VIN number to get the right part for your year and model type. /K&K

Yes if the head pressure on the high side is too low or water temp is below136F the fan will cycle on and off. The fan will kick off as well when the A/C clutch cycles off and on. /K&K

@@KNKRNR thank you so much for the response, looks like I have to trace some wires as both of the coolant temp sensors have been replaced.

I have read people just wire the two ends together and it just runs on high when the computer calls for low fan. /K&K

@@KNKRNR thanks for reply. I try and connect two cable eachother and right no fan operation but A/C is work well.. Another case low fan fuse 20A is gone and die ..

No this engine will run to 260F. Without the resistor the fan will not work. Its possible the AC head pressure can get so high it can cause the compressor to lock up and stop the engine. /K&K

@@KNKRNR I take a new parts and connect. change 20A fuse and A/C is good work now and no rough ıdle.. So more important part it is..

@@KNKRNR hi again, I change thermostat ETC and AC compressor for last stone resıstor.. But I have a problem.. When engine heat comes to 91 degree C AC off itself and on and off.... Why is that my last hope mister ( radiator fan engine, ETC sensor, AC Compressor, Stone resıstor change to new parts)

Once the coolant reached the boil point of 240-260F degrees it turned into steam and blow out the pressure relief port of the radiator cap. We were surprised the engine didn't lock up after that one. /K&K