Service 4X4 message

[Smoke chopper]

Hi everyone. Today my beloved 2003 2500HD Duramax/Allison truck displayed the message "Service 4X4" so I took it in. The dealer replaced the "transfer case shifter module" and they say that took care of it. I just wanted everyone to know......... I LIKE my Chevy truck!!!!!!!!!!!!!!!!!!!!!

[thechevyhdman]

Smoke Chopper I too took my truck in today for the service 4 wheel drive message.Actually it was there for other reasons, but had them check it out anyways. Alot of people have bee complaining about that message showing up on start-up or just driving down the road. And alot of dealers have been replacing the 4WD shift selector panel thinking that is the reason for the message at the message center. However, from what I was told only 2001 and real early 2002 models were plauged with faulty selector switches. I cant remember exactly what the GM Dealerworld web site said(I get to see everything at my dealership because a friend of mine is the head service manager)But the diagnostic system of the truck checks out all systems at a certain schedule(number of start-ups,miles driven, etc) Alot of time this message Service 4WD comes on at startup for this reason. The TCCM(I assume transfer case control module) Will not communicate with the TCM upon start-up becuase the TCCM is in sleep mode, Becuase it is in sleep mode it will throw out a Service 4WD message because the TCM is not Communicating with the TCCM. So basically what it is saying is if you truck is setting a code for lost communication between TCM and TCCM it is normal. Sometimes Id just jump in my truck and crank it right over,(when I know the glow plugs arent needed) My start up is so quick that not all operating systems are ready to run yet. This will also happen if you crank your truck over without waiting for the glow plugs to cycle. It will set a code for Lost Communication between Glow plugs and ECM. I figured I would post this because I have seen alot of people ask this question,Its no big deal The program to prevent this message from showing up again is included with the latest updates for our trucks. I believe after the update your S. 4WD message will only come on when there really is a problem. Bill

[conradv]

I too just had my service 4WD message come up, and when I took it in to the dealer I was told the same thing about the sleep mode. I even have printouts of the GM bulletin about it.

Hopefully it won't happen again, but if it does, they'll definately know about it....

[AlanL]

My truck got the "Service 4WD" message on Saturday morning. It has only happened once, and the 4wd system is working fine.

Should I bother to bring it in (the truck only has 3500 miles on it) or just wait until it happens more frequently?

I used the 4wd system on Sunday (we had some snow). No issues or messages.

-Al

[Brad Pelot]

Mine too!

[wheeler]

My DIC intermittently displays "Service 4x4". Transfer case button lights display indicates 4 Wheel Low but truck is in 2 Wheel High. Next day everything normal. Off to the dealer I go. --wheeler in 2003 D/A 2500HD CC

[Heartbeat Hauler]

"My DIC intermittently displays "Service 4x4".

Holy cow Wheeler, what does your wife say? :eek:

Sorry, I couldn't resist

[ 02-05-2003: Message edited by: Heartbeat Hauler ]

[ 02-05-2003: Message edited by: Heartbeat Hauler ]

[ 02-05-2003: Message edited by: Heartbeat Hauler ]</p>

[wheeler]

What does my significant other say to that?? "Must be a malfunction, I just did that service!!" So, thanks, Heartbeat Hauler, for your astute observation... guess I deserved that. What was I thinking?!?

But you bring up another oversight-- my DIC doesn't *intermittently* display the "Service" message -- that indicator's pretty much on all the time! --Red Faced Wheeler

[DMaxCaptain]

I have battling this problem from day 1. See thread at http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=7&t=004360&p=.
Latest from dealer is that 'GM says not to replace any more parts, it is a software problem and it will be 1-2 months for a fix'.

[Ron Richardson]

I've had the same "Service 4WD" message appear since day one. But I also have the pleasure of having the 4WD light panel go beserk and randomly change to 4Hi or N or 4Lo whenever it feels like it. Pressing 2W does nothing until it sits for awhile.

Took it to the dealer and they say it's the encoder motor and the part's on order. We'll see if that fixes it.

I've also had it not allow me to use cruise control. And, it feels and sounds like it actually does go into 4Hi when I'm on very twisty roads. Definate noise from the transfer case.

...my fingers are crossed that the encoder motor will fix all these problems.

[DMaxCaptain]

Don't count on the encoder unit fixing the problem. The changed my encoder unti twice and the Transfer Case Control Unit once. Still have the conditions that you descibed. The software fix that they are waiting on is suppose to fix all of this...

[Ron Richardson]

Changing the encoder motor DID fix the problem. I wanted to wait a couple of days to make sure and I can report that it now is working perfectly.

They replaced Part #: 12384987 Actuator 4.563

[GMC-2002-Dmax]

Mine has been displaying it as well.

When it won't go into 4wd I'll bring it in. If it dies then I'll call roadside assistance.

I don't wory about the small stuff.

Thanks to all for posting the problems ;)

GMC :D