Stuck in 4WD Hi - GM FIeld Action

[SILVER SLED]

I just checked with GM Canada and they don't know about this fix? That's the number you got or is it PIP 5220B? Where did the info come from? A dealer?? Hopefully we'll get it soon!

Yes, PIP 5220B. Have the dealer look for this svc bulletin. This bulletin is coming from a dealership.

 

This bulletin will fix most. However, if the problem occurs and has a certion code (can't remember code #) stored, this bulletin will not fix it. If that certion code occurs, it can be cleared and you'll still have to remember to shut off in 2wd.

Edited February 10, 2015 by SILVER SLED

[Magoomba]

My 2015 Sierra Denali got stuck in Auto 4WD this past weekend. At some point, it shifted itself back to 2WD and remained there until I brought it to the dealer today. The service form says "Corrected by Transfer Case Shift Control Module; Reprogramming with SPS; Checked for TCCM DTC S CO393 and CO38D; Found PIP5220B to reprogram TCCM; Reprogrammed TCCM and setup"

 

Since picking it up from the dealer, I've started, driven, parked 3 times, all leaving it in Auto mode since there's snow on the roads here. So far (knock wood...) it's been fine.

[Blizzard721]

Come on Silver Sled....think...that code number that it won't fix??? Is it C0398??? I hope not! That's the code mine is getting!

[tbarn]

Seems that the problem stems from the new calibration in the transfer case update (recall). Been told it will probably require an other software update and an encoder motor. They are not 100% sure yet. Parts may not be available for a while if the encoder motor is required. Be patient. It will be fixed.

[SILVER SLED]

Come on Silver Sled....think...that code number that it won't fix??? Is it C0398??? I hope not! That's the code mine is getting!

 

lol. C0398 is covered in the fix in PIP5220B, along with C038D and C0397. The one 5220 does not address is C0326 though, and C0326 is in bulletin 5250 which states there is no fix yet.

[Spurshot]

Interesting. That never seemed to be the issue with earlier model GM trucks. I know my 2006 Silverado never failed me that way. What did GM change in the transfer case shifting mechanism to cause this? It almost sounds like the shifting solenoid or something is freezing up in cold temperatures. Perhaps they started using lower quality parts that do not work well in cold weather?

 

They must have the transfer case dash switch sending a signal to the BCM or TCM, then onto the transfer case shift module. It's definitely not a direct path as with older trucks. Must be an "improvement".

 

http://www.advanceadapters.com/categories/atlas-transfer-cases/234/

[Cliff14Denali]

OK, so since I got my truck back a few days ago I have been hearing noises coming from the front drivetrain. I told the dealer that I had to drive the truck back from vacation in Vermont which they said it should be ok.....OnStar said it was OK to drive as well. I have been getting a weird clunk/thud coming from the front end at random times. It doesn't make noise going over bumps so I am ruling out a suspension related issue. It "sometimes" makes noise accelerating and decelerating. Making turns it "sometimes" makes noise......similar to being in 4wd like it was stuck. I dropped off my truck at the dealer today and they gave me loaner car until it was fixed. I knew something like this was going to happen but I never thought it would be in a few days. Be careful if your truck has the "Service 4wd" and make sure you have it towed to a dealer ASAP.....on GM's dime of course.

[51 ashton]

That's why I like the manual transfer case for that reason

[Silverado-Hareek]

Got our first snow down here. Just to be clear, I can switch back to 2wd in park as long as I don't shut the engine off right? Or am I supposed to do all my 4wd shifting in "drive"?

 

 

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Edited February 17, 2015 by Silverado-Hareek

[SILVER SLED]

Got our first snow down here. Just to be clear, I can switch back to 2wd in park as long as I don't shut the engine off right? Or am I supposed to do all my 4wd shifting in "drive"?

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Just make sure you switch to 2wd before you shut it off. Make sure you see the shift complete in display. Truck does not have to be in drive.

[SILVER SLED]

That's why I like the manual transfer case for that reason

I'm not sure the "manual" transfer case would be exempt from the problem. The manual t-case just uses a lever to send the electronic signal instead of a knob.

Edited February 17, 2015 by SILVER SLED

[nytronorm]

Does anybody know how I can clear this problem myself? I have scanned it with HPtuners but no codes are present. I can not keep going back to the dealer every few days.

[Silverado-Hareek]

Does anybody know how I can clear this problem myself? I have scanned it with HPtuners but no codes are present. I can not keep going back to the dealer every few days.

 

pull the negative terminal on the battery maybe and reset everything?

[pm26]

 

pull the negative terminal on the battery maybe and reset everything?

That's always a good thing to try, and you need to leave it disconnected for about a minute at least. Just make sure the ignition is off before disconnecting the negative battery terminal cable. I hope these trucks do not have "theft-proof" radios like some VW vehicles, where disconnecting the battery requires that the radio be reset by a dealer to work again. Just make sure this is not the case here.

Edited February 20, 2015 by pm26

[lowercanada]

 

pull the negative terminal on the battery maybe and reset everything?

It would be good to know if anyone has had success with that. Might save some people a trip to the dealer.

 

 

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