Weakness In Design DTC P059F

[Busa Dave]

This code is regarding the 6.6 Duramax do not know about the gasser design. Had to travel to the ranch in NM on Thursday during the winter storm. In short the engine fan came on and stayed on. Root cause is when in my case hundreds of miles in rain, sleet and snow blocked the louvers and they were stuck in the closed position. The truck defaulted to a fault found and turned on the fan lol.

The fan was very noisy especially when speeds increased to normal on the highway and when taking off from a stop and would not turn off. Buddy of mine looked up the code and found that it is a known issue on the GM trucks. Seems it is easy for debris or ice and snow to disable the function of the louvers in front of the radiator. Pulled off, went to a car wash and blew all of the ice mainly sleet made solid by rain and freezing temps with the pressure washer. The fan immediately stopped when I drove it. Took 3 stops and starts for the check engine light to reset.

Hope this helps anyone who has experienced this.

 

[AXE]

They ship with a radiator cover in the rear seat storage panel.

Also the Duramax Diesel Engine Supplement manual discusses this on page 10.

I would recommend installing it if driving in inclimate weather. It would be interesting to see if it fits the ZR2 grill since it's different than the standard 2500HDs grill tho.

Can you hear me now?

 

[DNZR2]

Thanks for sharing this important info.

 

[Busa Dave]

Yes, was at the dealer today and spoke to the tech on a different matter on my Colorado (stereo installer broke a data cable) and I was not the only one that had this issue. Seems that in this specific case it was a no win due to the temperatures. They varied from 30 to 34 degrees with large amounts of rain and sleet. It was too warm to use the cover as that would have triggered the same condition of the fan coming on and staying on because of lack of airflow when going slow and then back to highway speeds at these temperatures. When I was cleaning it out it was sleet when mixed with the cold rain barely below freezing allowing penetration into the louver mechanism/tracks over many hours and the airflow into the grill made for nice solid ice blockage not snow.

The fan roaring like I was pulling a load through the desert was a what really worried me. Am going to keep some deicer in the tool box however, doubt I will ever experience these specific conditions again.

 

[AXE]

Not sure if the stock cover is adaptive, but there are aftermarket covers that can be customized for additional airflow.

I live work and play where it might be -30F or it might be 120F. I've never had a heating or cooling problem. But if you don't adapt to the conditions you'll always have problems.

Hear me roar!