Took off tonight on wet streets with a temp just a little below freezing. Rained in the afternoon and then cooled down. 2012 Silverado was sluggish going into either auto or 4 high, and the check four wheel drive message came on. Appears to be working now. Is this common, and could the cold temps/wet streets have frozen something up on the outside of the transfer case? If you had a similar experience, let me know!
Does GM still use the heat activated actuator to engage the front axle? That thing was famous for being slow shifting in cold weather.
Does GM still use the heat activated actuator to engage the front axle? That thing was famous for being slow shifting in cold weather.
No. GM got rid of the heat actuators in 97/98.
There's nothing in the 4WD system that should be affected by snow or cold. If the problem reoccurs then take it to the shop.
I want to say my 2011 did this when it was raining. I can't remember what the fix was, but I think it was a warranty thing. Whatever it was I do not believe it was serious.
Message gone, and it will shift, but takes about a block to complete the 2 high to 4 auto (or 4 high) shift. All other shifts (4 to 2, even 4 high to 4 low, in neutral) are nearly instantaneous. Guess I haven't paid too much attention to the time/distance the 2 to 4 shift took before I saw the message. Is a bit of a delay from 2 high to auto or 4 high normal?
I always slow down to a crawl to shift and mine goes into either range almost right away.
Don't know about the newer ones but my 1998 Chevy has "shift on the fly 4wd" and it's not speed restricted. I don't put into 4WD at 70 mph but 50 mph is not a problem. Just ease off on the throttle and it shifts smooth in or out of 4HI.
Yes, 50 is not a problem, I just have no real reason to go into 4x4 at 50 (no snow around here). Gotta go slow for 4 low to engage.
My 2005 Silverado was doing that (showing that message) a few weeks ago and it wouldn't shift the transfer case at all. I finally pulled and replaced a few fuses that seemed related (none were burned out) and everything returned to normal. Go figure.
I've experienced the same thing. Generally the transfer case connector needs to be cleaned and make sure it is plugged in tight and dry. The next thing that generally fails on these is the 4x4 selector switch on the dash. Not very likely that it is the differential actuator or anything like that. The autotrac/autotracII and computer control devices on these GM's can and have been very troublesome to some. Do an internet search and you'll see what I mean. Changing the fuses like one guy suggested doesn't do anything. Especially when the fuses aren't burnt. Sometimes if your getting a service 4x4 soon display, you can turn the vehicle off, wait a few minutes and re-start and the problem seems to have gone away. You can also disconnect the battery cable and the same thing happens. If the problem persists, I'd be highly suspect of the 4x4 selector switch on the dash...
I didn't say I replaced the fuses. Pulling and reinserting the right fuse is the equivalent of disconnecting and reconnecting the battery, but a lot easier. Point is, it worked.
That's how I read it too Ed, but didn't feel like arguing.
I didn't say I replaced the fuses. Pulling and reinserting the right fuse is the equivalent of disconnecting and reconnecting the battery, but a lot easier. Point is, it worked.
If that worked, quite possibly disconnecting it reset something, kind of like rebooting a computer.
My 2005 Silverado was doing that (showing that message) a few weeks ago and it wouldn't shift the transfer case at all. I finally pulled and replaced a few fuses that seemed related (none were burned out) and everything returned to normal. Go figure.
Huh?
Sorry, "replaced" as in put back in place i.e. reinserted. I have an excuse but never mind. I'm better now.
