Cooling fan help

[opfor2]

Good morning,

I'm in a situation where I don't have access to my service manuals. Last night I got stuck in some pretty bad traffic and my 2011 Tahoe overheated. I was able to pull off of the freeway and allow the vehicle to cool and when traffic died down drove it home with no issues. Both of the cooling fans were not operating! I checked the fuse box under the hood and didn't see anything obvious. Any trouble shooting assistance would be greatly appreciated.

 

[Geotrash]

Good morning,

I'm in a situation where I don't have access to my service manuals. Last night I got stuck in some pretty bad traffic and my 2011 Tahoe overheated. I was able to pull off of the freeway and allow the vehicle to cool and when traffic died down drove it home with no issues. Both of the cooling fans were not operating! I checked the fuse box under the hood and didn't see anything obvious. Any trouble shooting assistance would be greatly appreciated.

Check the connectors at the bottom of the fan motors. They're known for overheating and shorting out.

 

[opfor2]

would that cause both motors to stop working? Also, they don't operate when the AC is on. I know for sure that the fans operated just the other day

 

[Geotrash]

would that cause both motors to stop working? Also, they don't operate when the AC is on. I know for sure that the fans operated just the other day

Maybe. Just the easiest thing to check. Next I would take a Tech2 and see whether or not the fans are being commanded to on or not. If so, I'd test the fan fuse for continuity and look at the relays, and check the wiring for continuity and shorts to ground between the fuse and the fans. There are 3 relays in the system for the cooling fans:

Circuit/System Description

The engine cooling fan system consists of 2 electric cooling fans and 3 fan relays. The cooling fan relays are arranged in a series/parallel (S/P) configuration. This allows the engine control module (ECM) to operate both fans together at low or high speeds using 2 fan control circuits. The cooling fans receive positive voltage from the cooling fan relays, which receive battery positive voltage from the underhood fuse block. The cooling fans are supplied a ground at G100 and G101.

Diagnostic Aids

• The ECM has the capability of providing command to the fan relays even while a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.
• The scan tool cooling fan output control operates as follows:
• Fan Relay 1 operates both fans at a low speed
• Fan Relay 2 and 3 operates one fan at high speed
• Fan Relay 1, 2, and 3 operates both fans at high speed

Here's the wiring diagram for a 2012 Yukon XL Denali. Should be similar for yours.

 

[opfor2]

UPDATE: Did my troubleshooting this AM and discovered that both cooling fan connectors are damaged due to heat (see pics) ordered two OEM replacements from RockAuto (https://www.rockauto.com/en/moreinfo.php?pk=2722228&cc=3015551&pt=2556&jsn=872) which should get here by tomorrow. So when my truck went into "Limp mode" it set a Cel and now I have a massage on the DIC to change my engine oil. I just changed it three weeks ago is changing the oil necessary?

 

[Geotrash]

UPDATE: Did my troubleshooting this AM and discovered that both cooling fan connectors are damaged due to heat (see pics) ordered two OEM replacements from RockAuto (https://www.rockauto.com/en/moreinfo.php?pk=2722228&cc=3015551&pt=2556&jsn=872) which should get here by tomorrow. So when my truck went into "Limp mode" it set a Cel and now I have a massage on the DIC to change my engine oil. I just changed it three weeks ago is changing the oil necessary?

There you have it! Thanks for following up. I don't think an oil change is necessary.

 

[donjetman]

UPDATE: Did my troubleshooting this AM and discovered that both cooling fan connectors are damaged due to heat (see pics) ordered two OEM replacements from RockAuto (https://www.rockauto.com/en/moreinfo.php?pk=2722228&cc=3015551&pt=2556&jsn=872) which should get here by tomorrow. So when my truck went into "Limp mode" it set a Cel and now I have a massage on the DIC to change my engine oil. I just changed it three weeks ago is changing the oil necessary?

If it got hot? YES change it. Here is how i know:

https://www.tahoeyukonforum.com/thr...2l-8600-miles-mobil-delvac-1-esp-5w30.117822/

 

[Foggy]

Thanks for following up with your solution !!!!!!!!!
I'd change the engine oil and the trans fluid.. It prob got really high
if it set a code...
The factory temp gauge is on a hair better than a dummy light....
It'll show 210* anywhere from 170-230*... so if the gauge got way
up on it's scale, it really got hot

 

[Geotrash]

If it got hot? YES change it. Here is homw i know:

https://www.tahoeyukonforum.com/thr...2l-8600-miles-mobil-delvac-1-esp-5w30.117822/

I totally forgot about that happening for you. You’re 100% right. Change that oil.