97 Camaro Z28 Cooling Issue.
 

Hello,

I am trying to help my brother with an overheating issue on his Camaro and am getting no where. I figured it wouldn't hurt to get peoples opinions and input.

The car simply overheats and starts to boil over because the elctrical fans never trigger.

This is what i have done to remedy the problem as well as some observations...
1. Replaced Cool Temp Switch.
2. Tested (3) Fan Relays which all are functional.
3. Traced CTS wire to ECU and checked connectivity. OK.
4. Both Fans operate with AC on.
5. With no CTS connected, fans come on ? normal ?

Any suggestions would be appreciated.
Pete

test temp sensor
http://www.shbox.com/1/4th_gen_tech2.html#ect
check here to
http://www.shbox.com/1/4th_gen_tech2.html#cooling

I appreciate the reading material crabby, i will take a look at it later today and let you folks know soon.

Does someone know if unplugging the sensor completely should trigger the fans on as it has in my situation ?

Thanks
Pete

yes it will, the computer sees on open curcuit/failure at the sensor and turns the fans on.

Read this'
https://camaroforums.com/forum/93-02-general-41/quick-test-engine-fans-54192/

Using a multimeter i back probed the CTS to watch its impedance as the car is running to see what the computer is actually seeing using the above linked chart.

What i found out is that the temperature/resistances make sense when the car is off. As soon as i insert the key or start the car the multimeter reads OpenLoop or Megaohms on another meter, which doesn't make any sense or does it ?

I also followed the proper bleeding procedures to make sure that air is out of the system appropriately.

Ideas ? ?

Pete

Well short of getting another computer/ecu, does anyone have any other suggestions ?

Pete

have you scanned it for any stored trouble codes?

Can their be any trouble codes stored without the check engine light on ?

Pete

yes. i had my memcal in wrong and it didnt show a ses light. did show a ecu code. the obd2 will store confirmed codes (3 or more occurrences) and passive codes (one or two occurrences)