Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Chevrolet > Avalanche | C&K | Silverado | Suburban | Tahoe > Silverado
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 08-30-2016, 08:16 AM   #1
yakkk
AF Newbie
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Reset "Service 4WD" code?

2004 Z71, recently was stuck in 4WD after coming off the beach. I removed the selector switch from the dash and it would work, pop it back in and it wouldn't. Replaced it with a Dorman switch and it now switches fine, but I still get the "Service 4WD" indicator after driving a while. It this a code that need to be reset manually?
yakkk is offline   Reply With Quote
Old 08-30-2016, 08:36 AM   #2
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,898
Thanks: 8
Thanked 432 Times in 431 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by yakkk View Post
2004 Z71, recently was stuck in 4WD after coming off the beach. I removed the selector switch from the dash and it would work, pop it back in and it wouldn't. Replaced it with a Dorman switch and it now switches fine, but I still get the "Service 4WD" indicator after driving a while. It this a code that need to be reset manually?
the 4wd service light comes on when it senses any abnormality.reset is done at each starting of the engine. my guess is the new switch is bad. I would get a GM drive train capable scanner and find out what the code is then post here . the old OEM switch does have solder issues so if you can do it properly re solder the switch pins on that ckt board.
j cAT is offline   Reply With Quote
Old 08-30-2016, 12:18 PM   #3
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by j cAT View Post
the 4wd service light comes on when it senses any abnormality.reset is done at each starting of the engine. my guess is the new switch is bad. I would get a GM drive train capable scanner and find out what the code is then post here . the old OEM switch does have solder issues so if you can do it properly re solder the switch pins on that ckt board.

I did save the old switch. I''l have a look at it and if I can resolder it, I'll see if that fixes the problem.
yakkk is offline   Reply With Quote
Old 09-27-2016, 11:43 AM   #4
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Re: Reset "Service 4WD" code?

Well it seems to have resolved itself. It's gone a few weeks without displaying the service indicator.
yakkk is offline   Reply With Quote
Old 09-28-2016, 06:13 PM   #5
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,898
Thanks: 8
Thanked 432 Times in 431 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by yakkk View Post
Well it seems to have resolved itself. It's gone a few weeks without displaying the service indicator.
probably the switch solder joints . temperature will effect this. also salty air ....
j cAT is offline   Reply With Quote
Old 03-18-2017, 05:06 PM   #6
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Re: Reset "Service 4WD" code?

Well, things were fine for a while, then about a month ago, driving in snow, I pushed 4Hi and it just flashed and went back to 2Hi. Repeated it a few times and it engaged. When I got to my destination it wouldn't return to 2Hi. I shut it off, started it, and while it was doing it's startup diagnostic I pressed 2Hi and it returned.

About a month later, I noticed it was a bit noisy on the road, and found that it had somehow jumped into in 4Auto. I had to do the same shut off/start procedure to get it back to 2Hi.

Now it won't light at all when I push 4Hi, 4 Auto, or put in N and push 4Lo. No flash, no light, just stays lit in 2Hi. I had used an inexpensive replacement switch, so I grabbed another at Autozone, but it still behaves the same, and Service 4WD indicator is back.

Guess I'll have to find a scanner that can read DTC's.
yakkk is offline   Reply With Quote
Old 03-18-2017, 05:29 PM   #7
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,898
Thanks: 8
Thanked 432 Times in 431 Posts
Re: Reset "Service 4WD" code?

so the 2wd light is on all the time . will not flash when you push the 4WD button etc.. what / how does the transfer case fluid look like ? level ? have had owners complain about this like you .. they never checked the fluid .. reason was they saw no leaks. then they finally checked the fluid no leak because no fluid LOL... post the drive train GM codes with GM capable reader type .. this will help.
j cAT is offline   Reply With Quote
Old 03-18-2017, 06:16 PM   #8
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by j cAT View Post
so the 2wd light is on all the time . will not flash when you push the 4WD button etc.. what / how does the transfer case fluid look like ? level ? have had owners complain about this like you .. they never checked the fluid .. reason was they saw no leaks. then they finally checked the fluid no leak because no fluid LOL... post the drive train GM codes with GM capable reader type .. this will help.

Correct on the 2wd light.

I have not checked the fluid. I will do that tomorrow. I'm also planning on cleaning up the ground wire connections, some folks have had success with that as well. My buddy has a scanner, I'll see him over the next day or two and report what we find.


Sent from my iPhone using Tapatalk
yakkk is offline   Reply With Quote
Old 04-06-2017, 11:40 AM   #9
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Re: Reset "Service 4WD" code?

Well, I replaced the encoder sensor ring, that didn't fix the problem. I just checked the fluid level, it was seeping out the fill hole, so it is full. Color is not blue, just a little bit off clear. Interestingly, as I turned the bolt, I heard a clicking sound that started and stopped a couple of times.

It now wants to jump into Auto4 every time I start it. I have to hold down the 2WD button until well after the startup lights clear before it will settle into 2.

I was able to get the codes scanned and it showed C0306 - Motor A/B Circuit Malfunction, and C0379 - Front Axle Circuit Malfunction.

The history codes showed C0306, C0359, C0374, C0379, C0550, B0790, B2725, U1301. Would be nice if they stored dates with the codes.

I'm thinking replace the encoder motor is the next step? (I've replaced switch, cleaned grounds, replaced encoder sensor)

Last edited by yakkk; 04-06-2017 at 12:12 PM.
yakkk is offline   Reply With Quote
Old 04-06-2017, 01:48 PM   #10
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,898
Thanks: 8
Thanked 432 Times in 431 Posts
Re: Reset "Service 4WD" code?

I never said to replace any encoder ring >>>. the fluid in transfer case must be blue. C306 means the encoder motor is bad. this can be the brake that locks the encoder it can short out or other issue. fluid is clear interesting . perhaps they put some engine oil in it . I would drain out the fluid see what was in there and put in the tracII fluid if it does match your vin#.. this tracII at dealership only so with the vin # you will be sure to have correct fluid. only tighten those transfer case plugs to 15 ft lbs MAX... that is a very soft metal. could be the wrong fluid killed it.
j cAT is offline   Reply With Quote
Old 04-06-2017, 02:31 PM   #11
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by j cAT View Post
I never said to replace any encoder ring >>>. the fluid in transfer case must be blue. C306 means the encoder motor is bad. this can be the brake that locks the encoder it can short out or other issue. fluid is clear interesting . perhaps they put some engine oil in it . I would drain out the fluid see what was in there and put in the tracII fluid if it does match your vin#.. this tracII at dealership only so with the vin # you will be sure to have correct fluid. only tighten those transfer case plugs to 15 ft lbs MAX... that is a very soft metal. could be the wrong fluid killed it.
Yeah, I saw that some have had luck just replacing the ring, I figured at $30 it was worth a shot. I have seen reports on new Dorman motors going bad in a couple of months, was thinking of going the ACDelco remanufactured route, any thoughts on that?

Last edited by yakkk; 04-06-2017 at 03:40 PM.
yakkk is offline   Reply With Quote
Old 04-07-2017, 07:12 AM   #12
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,898
Thanks: 8
Thanked 432 Times in 431 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by yakkk View Post
Yeah, I saw that some have had luck just replacing the ring, I figured at $30 it was worth a shot. I have seen reports on new Dorman motors going bad in a couple of months, was thinking of going the AC Delco re manufactured route, any thoughts on that?
some have purchased on ebay these encoder motors . they payed less than $100.. they did work.

the proper fluid is required because of this design. GM used dexron III in these back in the old days then had to change over to the trac II. on new trucks I believe GM now uses the dexron VI. I would replace the fluid with the proper GM spec . check with dealership as I said before. if it is trac II then you will have to buy at dealership the fluid. if they say dexron VI then you can go at auto store and get it cheaper. if that does not work then replace the encoder . also be careful as those wires are very fragile and must be covered with tape/loom material as many have had these get damaged from tech's being too ruff on handling . GM uses very fragile wiring esp . on the new trucks where wires break for no reason .
j cAT is offline   Reply With Quote
The Following User Says Thank You to j cAT For This Useful Post:
yakkk (04-10-2017)
Old 04-08-2017, 01:55 PM   #13
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by j cAT View Post
some have purchased on ebay these encoder motors . they payed less than $100.. they did work.

the proper fluid is required because of this design. GM used dexron III in these back in the old days then had to change over to the trac II. on new trucks I believe GM now uses the dexron VI. I would replace the fluid with the proper GM spec . check with dealership as I said before. if it is trac II then you will have to buy at dealership the fluid. if they say dexron VI then you can go at auto store and get it cheaper. if that does not work then replace the encoder . also be careful as those wires are very fragile and must be covered with tape/loom material as many have had these get damaged from tech's being too ruff on handling . GM uses very fragile wiring esp . on the new trucks where wires break for no reason .


Thanks JCat. I went with an ACdelco reman, it has a year warranty. I'll replace it and the fluid next week, hopefully this will do it!


Sent from my iPhone using Tapatalk
yakkk is offline   Reply With Quote
Old 04-09-2017, 07:56 AM   #14
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,898
Thanks: 8
Thanked 432 Times in 431 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by yakkk View Post
Thanks JCat. I went with an ACdelco reman, it has a year warranty. I'll replace it and the fluid next week, hopefully this will do it!


Sent from my iPhone using Tapatalk
post back how it worked out . a re-manufactured encoder I would not buy it. as you know where we live that electrical motor gets messed up with all the road crap and ice melting chemicals .. make sure it is not with any damaged/corroded housing damage.. GM does not use high quality metals on the under body components. my ABS got damaged ECBM because , the screws rusted out then moisture got to the electronic controller.
j cAT is offline   Reply With Quote
Old 04-21-2017, 01:14 PM   #15
yakkk
AF Newbie
Thread starter
 
Join Date: Jan 2009
Location: Marshfield, Massachusetts
Posts: 36
Thanks: 3
Thanked 0 Times in 0 Posts
Re: Reset "Service 4WD" code?

Quote:
Originally Posted by j cAT View Post
post back how it worked out . a re-manufactured encoder I would not buy it. as you know where we live that electrical motor gets messed up with all the road crap and ice melting chemicals .. make sure it is not with any damaged/corroded housing damage.. GM does not use high quality metals on the under body components. my ABS got damaged ECBM because , the screws rusted out then moisture got to the electronic controller.
I finally got a chance to install the new encoder motor. The motor seems to be responding to the control button now. I can get it to put the transfer case in Neutral, it goes into 4Lo (I hear the clunk), but the 4Lo light flashes instead of lighting solid, and the service 4WD indicator comes on. Same with 4Hi and 4Auto, the lights continuously flash instead of lighting solid.

I'm going to stop by my buddy's place and clear the codes to see if it throws any new codes. I'm also wondering if the existing codes can be confusing the TCCM?
yakkk is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD

Go Back   Automotive Forums .com Car Chat > Chevrolet > Avalanche | C&K | Silverado | Suburban | Tahoe > Silverado

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 02:24 PM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts