Transfer case issue

[shad0wrider]

Hi everyone, I'd like to get some feedback on an issue I just had with my truck. I'm wondering if anyone has had this happen to them...

 

Over the weekend I got into my truck, started it up as normal, and my transfer case was in 4W High. I hadn't used my 4 wheel drive in about 2 weeks, I know I didn't accidentally push the button. In any case, it would not switch out of 4WH. It wouldn't even try, meaning the lights would not flash indicating it was trying to disengage. I tried going to 2W and to 4WL, driving in reverse, and all the usual transfer case shifting solutions to no avail. The truck was finally towed to the dealer under warranty.

 

Here’s what the dealer said the issue was… Apparently, they got into it, turned the truck on and off, then on again, and the problem disappeared. I was told that I most likely “turned it on too fast”, and that with all new vehicles, because of the computer systems, I should always insert the key, turn it a notch, wait one second, then start the vehicle. This is due to the fact that their computers “go to sleep” at night, and if they are turned on too fast, you can basically disrupt their “waking up”, causing glitches like this. They also said this is not the first time they have seen this issue. They also called GM for advice and a possible software update, but GM had none to offer.

 

Has anyone ever experienced an issue like this? I think that the dealer’s response is ridiculous, and is only due to the fact that they cannot locate the exact cause of the problem.

[Mighty HD]

I've never heard of it going to sleep....lol My Hd sits 5 days a week till I drive it on the weekends, I flip thekey fast and it starts right up....just as it should.

[shad0wrider]

I agree, seems very strange. I hope it doesn't happen to me again.

[Kgry]

This is kinda off topic but two weeks ago I had my truck in 4lo trying it out in the snow. Well I was going to shift out of 4lo but putting the trans into neutral at a slow roll when I accidentally shifted into reverese! My truck just stalled, I assumed that was a secutiry featured so you don't ruin your trans, right?

[linda]

My truck will sit in the garage anywhere from 5 days to 15 days between uses. I have a daily driver that i use for going to and from work (91 silverado). I use my HD for trips and vacations. Even after the longest down times, 2 weeks or more, I have never had a problem even similar to this.

[deve8edsilv]

computer = , i call

[rascal]

some sort of power saver ideal? I know the interior lights go off if I leave one the doors open too long. like over night, don't ask.

[deve8edsilv]

some sort of power saver ideal? I know the interior lights go off if I leave one the doors open too long. like over night, don't ask.

 

<{POST_SNAPBACK}>

 

 

 

ha ha--- same thing with the parking lights, i think. i left them on for like 2 days and my battery was not dead and they were not on when i got in. the switch was still on though.

[Yukon04]

I reserructed this one after reading the responses and the created post. The dealership was correct when stating that the modules "go to sleep" and "wakeup" upon vehicle key/ignition cycles. The modules on the vehicle (all of them) have a feature that requires them to "go to sleep". The sleep feature of the module is to reduce parasitic loads during vehicle storage or non-usage. The modules are designed such that the are still active for a short period of time after the vehicle is turned off. After "X" amount of time, they go to sleep. This means they reduce the amount of "activity" within the module to decrease parasitic loads.

 

With the amount of electrical modules in vehicles these days, parasitic load is a large concern. 20mA will kill your battery in 30 days. 100mA will kill your battery in 2-3 days...

 

Just thought that I would explain that the dealership wasn't crazy when they tried to explain it.

 

The reason for the error is still questionable, because it does not make sense. The wake-up process in the modules is not something that is "interrupted" ???

This part is the part of the story....

[HDSpence]

My truck is doing the same thing -only when I start it, the 4lo button light is illuminated, yet the x-fer case is in 4 hi. difficult to get it out. Have to drive it, shut it off, turn key on and off, mess with it until it finally shifts back to 4hi. Then service 4wd comes on along w/ the engine light. I know the dealership will break it off in me if I take it to them -mines out of warranty -04 w/ 95k on it. Any ideas, fellas?

[GetMore]

My truck is doing the same thing -only when I start it, the 4lo button light is illuminated, yet the x-fer case is in 4 hi. difficult to get it out. Have to drive it, shut it off, turn key on and off, mess with it until it finally shifts back to 4hi. Then service 4wd comes on along w/ the engine light. I know the dealership will break it off in me if I take it to them -mines out of warranty -04 w/ 95k on it. Any ideas, fellas?

Check for service bulletins on your truck. This is a known problem. I don't remember what the fix is though.

[ak63]

I had an odd problem today possibly related to module startup with an 07 GMT900. I inserted the key and immediately started the engine. I found that the indicators worked (both externally and on the instrument panel) but did not click, and the radio was off and did not display the time. When I turned the radio on and then off, the time was displayed as usual and also the indicators started clicking! I did not switch the truck off. So perhaps there is some odd electrical startup issue?