TSB on encoder is failing due to heat/no 4x4

[TxDoc]

This is from another forum. I am passing it along for the general informtion content. If you are interested in the link, let me know. I did not see any related info already posted on TDP.

The posted info is from rileythedog:

1st post--
I managed to talk my father in law in ordering a 03 Duramax. He took delivery of it last Friday.

As a GM employee I was rather upset that the GM dealer pulled the fuse to the 4X4 so he could drive it. At 35 Kms his service 4X4 came on. The same dealer said they have 4 so far that the 4X4 does not work. GM has no fix yet and there is a bulletin out on it.

Has anyone seen this bulletin or familiar with this problem?

2nd post--
Well I talked to the dealer today. The bulletin is # 03-04-21-001(12-43-129) dated Feb 14 03.

The gist of the bulletin is that the encoder is failing due to heat and /or vibration causing fluctuating voltages to the computer. They recomend not replacing the encoder as it may be a temporary fix.

One other new owner had to limp back to the dealer with "4x4 Lockup " in low. They pulled the fuse.

Sounds like we are all on the same page here.

Heavy Duty if you can please post a repair procedure info # so I can forward it to my/his dealer. The service manager is not being to pro-active concerning this.

3rd post--
If anyone is interested the repair bulletin is # 03-04-21-001A dated April 17 03. Proceedure and parts are listed.

[Wing'n'it]

I've had the same problems with my '03 since delivery in Dec, 02. Dealer said to wait until GM had a permanent fix.
Saw dealer on Friday, 4/25 and new bulletin dated 4/17 says parts (new encoder) would be available for order on 4/28. Called dealer today, 4/30 and parts are on back order with an unknown ship date. Dealer says to keep checking back as they don't have anyway to get an ETA for the parts until they show up.
I don't know about you guys, but after spending $40k+ on a truck that was supposed to be 4x4 I'm a little p****d off. Seeing as this is a fleet wide problem, GM's handling has been poor at best. I'm thinking state lemon laws, class action or at least an extension of the powertrain warranty. Who knows what is really happening when my auto 4x4 selector says 4LO and I'm on the freeway at speed.
Any thoughts aas to how we can hold the general's feet to the fire on this one?

[TxDoc]

Wing'n'it

I was curious as to whether you may have registered at https://www.mygmlink.com/main/US/en/gmc/home ? I got a recall notice on my 2003 before the dealer. And, I wondered if this site had this info and what date it popped up?

The site also includes:
Maintenance reminders
Recall and safety information
Service history tracking
PDA applications
Your owner's manual
Vehicle value estimates
Warranty and service information
News and events
Special offers and privileges

[Nixter]

All you have to do is pull the fuse out of the underhood fusebox until you get it fixed. Then if you need 4wd just pop it back in and push the button. I have done this a couple of times when I needed to, and it worked without fuss. It's inconvienient, but easier than locking hubs IMO. I'm not happy with it, but I will take it over a leak any day. --Nick

[Burner]

Doc,

Could you post the link exactly?


Nixter,

Which fuse is it exactly?


Thanks Fellas,
Burner----------> :rolleyes: :D

[Nixter]

Burner,
On my truck the fuse is in the row furthest to the drivers side, and second from the firewall. It's a green 30 amp fuse, and unmistakable from the others around it. When I pull the fuse I still get the "service 4wd" message on the DIC, but absolutely no shift activity, or lights on the button panel. And when the fuse is in, and the system malfunctions it has returned to normal after shutting off, pulling fuse, restarting, and reinserting the fuse. Sorry for poor grammar, and redundant sentence structure, it's too early in the morning yet. --Nick ;)

[conradv]

TxDoc,

I signed up at mygmlink as soon as it would accept my 2003 VIN (about 2 months after build) and haven't heard any recall from them. And I just checked and there are no recalls listed for my truck. ('03 GMC 4x4 CC LB)

???

p.s. - I've only had the Serv 4x4 message 3 times but I use the 4x4 quite a lot... And it's the principle of the thing...

[ 05-01-2003: Message edited by: conradv ]</p>

[TxDoc]

Here's the link

http://www.gm-trucks.com/cgi-bin/ib3/ikonboard.cgi?s=b21ffa8376449975b81c3c8**9e3d265;a ct=ST;f=4;t=17917

Hope those with the problem get it sorted out properly.

[conradv]

Thanks - I had been following that thread. I thought you meant that you got a recall notice from mygmlink.com, and the dealer has gotten the same. You're just talking about the bulletin?

[TxDoc]

Yeah, that was just the thread about the problem and fix. The only bulletins I have seen are the ones mentioned in the first post.

[Wing'n'it]

TxDoc,
Sorry for the delay in an answer, but yes I did register at MyGMC, but never received any communication from them regarding this issue. I checked recalls a couple of weeks ago, and found none listed for my VIN. I did not check for TSB's.
I have made the assumption (you know what that means!) that all of those that are reporting this issue have the same drivetrain set up. In my case it is a 2003 GMC with DMax, Allison 1000 and electronic 4x4. What I have experienced is an intermittent "Service 4x4" DIC message and occasional inability to use electronic 4x4 selector. This manifests itself at start up with the 4x4 selector indicating 4x4HI, 4x4LO or neutral, yet the truck does not feel to be in 4 wheel drive, and certainly not 4x4LO!
I have been successful in cancelling the DIC message by pressing th "enter" button on the steering wheel. As for the erratic operation of the electronic 4x4 selector, sometime it clears itself after shutdown/startup, but not always. On at least two different occasions, first drive of the day, I heard the gear "moan" from the transfer case as I drove. This usually went away with the first mile of operation. Also, when this happens the cruise control is inop and I believe the anti-lock feature of the brakes is inop also.
I wish I could give you the TSB number that was recently issued and the part numbers that are on B/O, but I didn't get it from the dealer. I will try to get that info to share with everyone when I return home next week.
Hope this helps to clarify my previous post.

[conradv]

That'd be great, wing'n'it - I too would like to know.

And I'd tell anyone who is having this message pop up to take it in to the dealer with the codes still stored just to get it on record with the dealer. Then if the computer has caused damage to the t-case or encoder motor that only shows up way down the road (even after a fix is found), it's on record as a probable source of the problem.

[Nixter]

Wing'n'it,
I had the gear moan as well. Pulling the fuse ended it completely. Better off to curtail possible damage regardless of who is at fault.
Everyone else concerned,
Most folks seem to be content that their problem is confined to electrical components, and not doing any mechanical damage. I would advise you to turn off your stereo and listen closely for the first three minutes or so after you start your truck and go a few times. You may have the gear moan as well, and should at least know about it. I would not be suprised at all if some T-cases are being damaged from this. --Nick :rolleyes: :rolleyes:

[conradv]

Takin' her in for the "new" fix tomorrow.

Dealer said that the new fix doesn't involve just putting a new encoder motor on, but multiple other fixes. Said he just got the fix very recently from GM. Since I was on the list, my parts are there, but they are on backorder for new cases.

We'll see after tomorrow....

Supposedly this is a permanent fix.

[sonofagun]

Can I assume this is particular to the 2003 models or do I have a potential problem on a 2001?

Thanks,
Bob

[Nixter]

Son of a Gun,
This is a 2003 thing. As far as I know the failure rate was low for the 02s and 01s. I think only electrical parts were changed for 2003, and they are the problem. --Nick

[Bush Pilot]

I had the same message and problem with my 03 and took it in to the dealer. They changed the encoder and reprogramed. That seemed to fix it. Last month I was in for and oil change and asked if they had a permanent fix yet. They said yes that they had some new parts coming in that week and since mine had experienced the problem they would fix it. They changed the encoder again, Haven't had any more problems. But I don't drive mine much.

[Maverick]

I've never had this problem with either of my 01's.

Bush Pilot,
Do you got a float plane? I wanna do some Northern Pike fishing on Alexander Lake.

[Trippin]

They changed the encoder on mine and problem is gone............for now.

[TxDoc]

Just checking back to see if anyone else has experienced this and if the same fix is in use.

[dmaxalliTech]

Originally posted by TxDoc:
Just checking back to see if anyone else has experienced this and if the same fix is in use. We still see the problem and still fixin with replacement of senser in encoder motor, no comebacks yet :D

[jbplock]

For those that have had this this problem, do you use your 4WD alot? I had the error display once after parking overnight on a slight hill. After I shut down and restarted, the errror went away and has never returned. I also don't use my 4WD very often. Does the error tend to appear with frequent 4WD usage? Just curious... smile.gif

[Nixter]

I used my 4wd almost every day for about six weeks and never had the problem. It actually first happened at a time when I was only using it a couple of times a week. I think I was parked in my driveway at the time. I had the new encoder installed under warranty a couple of months ago and no problems since then. --Nick