# Service 4WD



## DareDog (Oct 22, 2007)

2005 1500 5.3L with 72K on it last night the "service 4WD" came on the dash and 4x4 did not work. once shut truck off and started it the 4x4 worked. not sure what that means? how do i get code from it? Thanks


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## cubicinches (Oct 19, 2008)

You need a scan tool. 

My guess is you'll have a CO327 code. More than likely it's the position switch inside the encoder motor. Or, the motor itself ($$$). The dash switches themselves fail often too, but more so on earlier models. Mid 2000's seem to have more encoder motor/position switch issues.


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## DareDog (Oct 22, 2007)

what is cost on parts for it?

i have scan tool i will put that on it and check.


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## cubicinches (Oct 19, 2008)

The position switch is about 50 bucks or so. The entire motor is upwards of $400. I think there's places you can buy a remanufactured motor for around $250... I've never gone that route, but I've heard of guys getting them for that much.


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## DareDog (Oct 22, 2007)

Just put the scan tool on it and there is no code and there is no "service 4wd" on the dash. does it reset?


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## cubicinches (Oct 19, 2008)

DareDog;1426381 said:


> Just put the scan tool on it and there is no code and there is no "service 4wd" on the dash. does it reset?


Does the 4WD work now?


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## B&B (Nov 4, 2006)

Unless you're using an enhanced scanner you won't retrieve any stored C codes, or B or U codes for that matter. But if it set one it will still be in there for a while so scan it with the proper scanner to assist in tracking the issue down. Most times it is a faulty position switch as CI mentioned but don't shot gun it, find out first.


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## DareDog (Oct 22, 2007)

Have a OBD II scanner,


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## B&B (Nov 4, 2006)

OBDll doesn't mean enhanced. Need to be far more specific than that.


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## cubicinches (Oct 19, 2008)

You need a Snap-On Solus Pro or Modis, Mac or OTC Genisys, or a GM Tech II... or something equivalent.


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## Plowtoy (Dec 15, 2001)

My boss just had this problem with his 04 Yukon, GM offered 5 encoder motors for his truck. Ended up that the encoder sensor was not replaceable for the one he had. He ended up getting a new encoder motor at the dealership. Diagnosed, installed for $550.
NAPA does offer a couple of them for about $250-$300.


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## oneoldsap (Dec 26, 2011)

I have had no luck with any aftermarket electronic components on GM vehicles . Either they don't last long or don't work at all !


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## chevyzrule810 (Oct 5, 2010)

My 2006 2500HD service 4WD light was coming on at 48,000 every once in awhile then more frequent.I changed 4x4 switch on the dash and it hasn't come on since truck has alittle over 60,000 and light hasn't come on.


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## DareDog (Oct 22, 2007)

just bought the truck 2 months ago and it had 2 month warranty called them they said most times its the motor and to not worry about it. i had it come on 3 times in 5 miles the other day.


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## goel (Nov 23, 2010)

Had the service 4wd come on once. Truck was out working in the summer so sent it into the shop the next day.

Will always stop and not finish the route after that one. 

New transfer case.


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## DareDog (Oct 22, 2007)

now none of lights light up on the dash (2wd 4x4 hi low auto 4wd) what dose that mean?

going to try to get it scanned soon.


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## cubicinches (Oct 19, 2008)

You mean it hasn't fixed itself in a month and a half?


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## Squires (Jan 9, 2009)

DareDog;1438232 said:


> just bought the truck 2 months ago and it had 2 month warranty called them they said most times its the motor and to not worry about it. i had it come on 3 times in 5 miles the other day.


light comes on for a reason, don't buy the BS about it not normally being an issue, get it fixed with the warranty unless it has for the dealer conveniently ran out.
if it ran out, get it scanned, takes a matter of minutes, and fix it yourself


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## Strictly Snow (Mar 6, 2006)

Recently had same issue on my 99 it was the encoder motor(transfer case motor) 3 bolts hold it to the side of the transfer case and two harness plugs 10 min swap part was $179.00 but that was my problem yours may be something else


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## DareDog (Oct 22, 2007)

the dealer is 2 hours away and it did it when test drove it, going to call them and see what to do.


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## DareDog (Oct 22, 2007)

put switch in in the dash did not work, thinking now its switch on the encoder motor.


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## Holland (Aug 18, 2010)

DareDog;1519908 said:


> put switch in in the dash did not work, thinking now its switch on the encoder motor.


So your just throwing parts at it?  Properly diagnose a problem before you buy any parts.


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## cubicinches (Oct 19, 2008)

Holland;1520090 said:


> So your just throwing parts at it?


For nearly a year now...


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## ffjs87 (Nov 24, 2012)

I spent almost an entire year, and about $700 for a factory encoder motor to fix my problem. It turned out to be a broken wire. The encoder motor that was in the truck still works fine, so I've got $700 sitting on a shelf. I had to pull the wiring harness out of the truck and check continuity to each wire. I finally got to one with intermittent connection. When inspecting further i found a small slice in the jacket and a lot of green corrosion. I replace a 6 inch segment of the wire and it has worked fine for the past 3 years.


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## seeyaa (Jan 27, 2008)

Had a Service 4WD on my 04 Tahoe, bought the encoder sensor from the dearler for around $80. Took the motor apart and found it was corroded inside. Bought encoder motor from Autozone for $297 with a lifetime warranty. Has been working perfectly.


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## DareDog (Oct 22, 2007)

Checked the ground and cleaned it and my dad thinks its fine now i dont think its fixed he thinks it is cause service 4x4 light has not come on 

my dad dose not want to pay the diagnostic fee to get it scanned.


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## 2COR517 (Oct 23, 2008)

If he doesn't want to pay the fee that's fine. Just buy the test equipment and you can diagnose it yourself


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## Sawboy (Dec 18, 2005)

DareDog;1527169 said:


> Checked the ground and cleaned it and my dad thinks its fine now i dont think its fixed he thinks it is cause service 4x4 light has not come on
> 
> my dad dose not want to pay the diagnostic fee to get it scanned.


Penny wise - dollar foolish


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## cubicinches (Oct 19, 2008)

DareDog;1527169 said:


> Checked the ground and cleaned it and my dad thinks its fine now i dont think its fixed he thinks it is cause service 4x4 light has not come on
> 
> my dad dose not want to pay the diagnostic fee to get it scanned.


Checked and cleaned what ground?


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## DareDog (Oct 22, 2007)

under the truck near drive side ground to the switch?


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## DareDog (Oct 22, 2007)

Got it scanned and its the motor.


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