Cold Weather Issues

[CaptainCanuck]

Overnight temp of -35 C, block heater plugged in. Went out to start truck and engine cranked about 3x longer than usual (not the first time it's been this cold). After about 15 min idle, started my trip home and put the 4x4 switch to auto. Stopped to get a coffee, and when I put it into park the service 4x4 message came on. First time it's happened after being told by service to keep it in 2wd when starting or shutting down.

 

Drove 50 min on the highway, and stopped at Walmart before hitting the dealer to reset my 4x4. Spent about 20 min shopping, and when I tried to start the truck it cranked for a short time, engine light came on and stopped cranking. Tried again, started and got the engine power reduced message. Luckily the dealer was just down the street, cuz it runs like a complete bag of shit in this mode. Accelerator to the floor just to get 40km/hr.

 

So here's the skinny on what the tech did to fix it.

 

Service 4x4 - tech cause: c0326 5b range lock actuator control system, reprogrammed with updated sps

 

SAS light on - engine controls ignition relay feedback circuit p1682 00 ignition 1 switch circuit 2 - replace kr75e engine controls ignition relay

 

Reduced engine power - no codes found - installed screw to leave exhaust door open, possibly frozen closed

 

Haven't noticed a difference with the flapper open, but haven't driven it over 60 km/hr to see if it gets louder.

 

I'm kinda amused that my winterizing list now includes my truck. If you live in the great white north, you might want to do the same and keep the valve open. Once the engine goes into reduced power mode, you'll need a tow if your dealer is not a couple minutes away.

[lewandojh]

Thanks for the post! I live in New England and got hit with -20 degree temps last week and received the Service 4x4 message as well. Good to know I am not the only one with this problem.

 

I'll keep an eye out for the other issues.

['01LS1]

Overnight temp of -35 C,

 

You lost me right there. I would either have to become a snow bird & fly south for 6 months or just flat out move.

 

But will link your post over to someone else that mentioned cold start issues.

[CaptainCanuck]

 

You lost me right there. I would either have to become a snow bird & fly south for 6 months or just flat out move.

 

But will link your post over to someone else that mentioned cold start issues.

Then I won't tell you what the temp was with the wind chill [emoji32].

 

It's hard to believe GM didn't see the issues with the TCCM or exhaust flapper in their testing. I live couple minutes away from their cold weather test center, and remember seeing zebra camouflaged trucks driving around the winter 2013.

 

Some bean counter made the decision I guess that the percentage of owners who would have these issues wasn't worth the cost of a design change.

[Aaron1085]

Biggest problem I have had is driver seat heater stopped working, start up (crank) takes abnormally long on temperatures below 30 and sensors never work in cold temps.

 

 

Sent from my iPhone

[Bonker]

I had the service 4x4 message as well. My mirrors were folded in when I parked the truck, they would not open they were frozen. I had to get my heat gun to thaw them out now they are open, I guess these so called engineers never really tested these trucks in the great white north.

[elwood3820]

I had the same problem this weekend with my 4x4 being stuck and the service 4x4 message came up. I took it in to the dealership and they said that if it goes below 32 farenheit (or 0 degrees Celsius for our friends to the north) that if I have it in 4WD I need to switch it back to 2WD before I turn my truck off so it doesnt get stuck in 4WD like that again and I have to do that every time which is lame. They said they havent found the problem to it which is why i need to switch it from 4WD to 2WD everytime.

[putz173]

hope they fix the 4wd auto thing soon, happens on the canyon too

[K9Z71]

I have a 2014 Sierra and I live in texas where it rarely gets below 30 degrees and every morning my truck cranks longer than usual before it starts. Took it to dealership and they told me GMC's have this issue in cold weather. Im not very happy with that answer! Its almost embarrassing to turn on in front of people because its a brand new truck and starts slower than older vehicles....

[redwngr]

Dealer is correct about the crank time. There is a (previously posted) GM chart that gives approximate crank time vs temperature. (I don't think GM considers it 'an issue' -- just a characteristic of the fuel system)

 

Bump the key and let it take over and do it's thing.

 

More info here:

 

http://sandyblogs.com/techlink/?p=2971

 

And here:

 

http://sandyblogs.com/techlink/?p=3134

[euromade]

My 2014 Chevy would do this especially when filled with E85. The same applies to the 2015 Sierra. I guess it is "by design" as my truck always starts up via the OnStar App. I guess if something was wrong the remote start would give up...