05 Silverado Service 4wd

I got the Service 4wd message, so the first thing I did was order and replaced the switch. I thought this fixed my issue until I used the 4wd this weekend and the 4wd message started coming back. I'm not sure if it was actually using it 4wd or just the bumpy dirt road that kicked it off but the switch doesn't seem to be the issue. Any ideas out there regarding which route I should take next?

How doe's it run with 2x2, and 2x4?
A service light might indicate that the transfer case is low on oil, or broken.

Seems to run fine. Only the display message is the issue that I know of. What would I notice if something was wrong with the transfer case?

Seems to run fine. Only the display message is the issue that I know of. What would I notice if something was wrong with the transfer case?

what is the color of the trac II transfercase fluid ? the encoder motor may be drawing too much current , or the switch you just bought has bad solder joints.

If the transfercase fluid is clean and blue in color. the switch has good solder joints. then get the drive train codes pulled for the cause. you will need a gm specific drive train code reader..........

I had a transmission shop run the error codes. I have code C0327. Something to do with a Encoder Circuit Error. Suggestions?

I had a transmission shop run the error codes. I have code C0327. Something to do with a Encoder Circuit Error. Suggestions?


this is the transfercase encoder motor not giving proper feedback to the computer as to its position or input power circuit.

you will find many have had encoder motor failures causing this code....on occation it is a bad wire or connector...

when fluids are not replaced often the encoder must work much harder to move, this is when this small motor gets damaged..

some have found when the motor was removed the transfercase forks needed some movement until they required less force to change position.

I asked before what is the fluid color ?

Truck has 65000 miles. Fluid has never been change and it's black in color.

Truck has 65000 miles. Fluid has never been change and it's black in color.

black means death ..........your screwed !

So, what are you saying? Should I take it to a local mechanic or dealership?

So, what are you saying? Should I take it to a local mechanic or dealership?

If you're not sure about it, it is adviseable to ask an advise from the expert or bring it to the mechanics. That's the best option so far ;)

So, what are you saying? Should I take it to a local mechanic or dealership?

with the fluid black this is most always a complete removal/rebuild. fluid needs replacing with light use every 30-40,ooomi..if used often some replace every 10-15,ooomi. every oil change all these drive train fluids need checking for level and condition.

ask your friends where you should bring the vehicle for repair.

call to confirm that they have the ability and prior experience in this type of work.

most times the clutches are worn .

how often do you use the 4wd ?

I hardly ever use my 4wd. Maybe 3 times a year during hunting season. From my understanding the sensor can also be the problem and I was hoping for that since my truck doesn't have any issues going in and out of 4wd until the message pops up. I have found a repair shop with this type of experience. They are talking $500 if the full motor needs replacing where as the local dealership has qouted me $727 for motor plus $179 labor. If only sensor part is only $103.

I hardly ever use my 4wd. Maybe 3 times a year during hunting season. From my understanding the sensor can also be the problem and I was hoping for that since my truck doesn't have any issues going in and out of 4wd until the message pops up. I have found a repair shop with this type of experience. They are talking $500 if the full motor needs replacing where as the local dealership has qouted me $727 for motor plus $179 labor. If only sensor part is only $103.

as with any expensive repair you must insist that they guarantee the fix in writing before work is done..

don't want to have them charge you 700.oo for parts and labor only to find the transfercase is blown ! some have !

make sure they check the fluid condition before they start any work ..

you could replace fluid to see if it makes a difference..need 3 qts trac II fluid . with the encoder no fluid would be used to replace ..or just have them do it all ..

Thanks. I think I will replace the fluid first to see if it makes a difference. If not, I will have a mechanic look at it. What I hate is that no one can give me a solid cost for the repair without charging me a diagnostics fee. This makes it hard to shop around.

Thanks. I think I will replace the fluid first to see if it makes a difference. If not, I will have a mechanic look at it. What I hate is that no one can give me a solid cost for the repair without charging me a diagnostics fee. This makes it hard to shop around.

get a worse case cost ..a complete rebuild with a warrantee...

like I stated before black is usually a complete rebuild..

black is the clutch material..also metal wear..

I replaced an 05 transfer case on a Yukon with the Automatic AWD , and two months ago I also replaced a transfer case on a2001 Silverado 2500HD, on the Silverado the gear cluster exploded and wore right through the case, no fluid at all in the case and the owner drove it like that from Arizona to Alaska. The cause? He had two different tire brands on the front and rear and drove in 4WD on dry pavement.

On the Yukon the owner would ignore the tire pressure warnings and continuously drove with LF and RR low air pressure tires and in 4WD on dry or icy roads here in Alaska. Burnt up the gears from gear loading.

I work for both of these owners as a fleet mechanic, also about that selector range gear motor, they can be bought online pretty cheap, all you need is a 15mm socket and ratchet, they do come off tight as there is thread locking compound on them.

If you don't have a skid plate under your transfer case where that motor assembly is you WILL damage it easily, its a plastic housing. Its not hard to get at but you will have to remove the front propeller shaft to get some room and the harness plug is tricky as it has a safety keeper clip.

Most important is that you CANNOT use ATF or Mercon fluids in a transfer case with the Automatic 4WD, you have to use the blue GM fluid. If its black on either the Automatic or the conventional case its probably because of something inside thats overheating and burning the fluid.

So in summary....keep all the tires the same brand and same air pressure and also another suggestion, check the front differential fluid quality, on both vehicles the front diff was dirty, I use 75-85W synthetic gear lube in both of these vehicles and also my 2002 Silverado 3500 dually.

You know that you said that seems like at some point in this trucks life, I did look down and notice my truck was in 4wd when I started turning one day. I'm was on payment and have no idea how long it had been in 4wd.

Also, I was going to go ahead and let a mechanic do the work but last night I read that GM has a transfer case module software update that will prevent this message error in the future, so I may have top let the dealership do the work so the it can be reprogrammed after installing the new sensor. Anyone heard about this?

You know that you said that seems like at some point in this trucks life, I did look down and notice my truck was in 4wd when I started turning one day. I'm was on payment and have no idea how long it had been in 4wd.

Also, I was going to go ahead and let a mechanic do the work but last night I read that GM has a transfer case module software update that will prevent this message error in the future, so I may have top let the dealership do the work so the it can be reprogrammed after installing the new sensor. Anyone heard about this?


if you have no 4wd issues with a service 4wd warning light I would say possibly ..since your transfercase is damaged and the light indicates issues with the encoder motor I think not...

Do you think I would be less expensive in the long run:

taking my truck to the dealership after it was fixed and ask them to update the TCCM?
or
let the dealership do everything and update the TCCM while they have it already there?

Do you think I would be less expensive in the long run:

taking my truck to the dealership after it was fixed and ask them to update the TCCM?
or
let the dealership do everything and update the TCCM while they have it already there?

after the vehicle is repaired have them check that your vin # vehicle requires a software adjustment.

right now it is not clear what is needed to repair this ..

if this transfercase is badly worn I would replace with a new one .in the long run this would be the least problematic..this is with your keepng this for another 5-6yrs.

the dealership will cost you much more ..so go to a recommended shop that has done a lot of this work..

what ever you do keep the fluid clean and replace when getting gray.
rotate your tires every 10-13,ooomi..

all tires must have the same wear..same type/size etc...

get warrantee/cost for repair/or a new unit..

post back what was damaged..how much on the costs ..

The damage was not so bad. The mechanic said the fluid was dark but he wouldn't call it black, it just needs to be changed. He said it did not smell burnt. He said the sensor just needed to be replaced.
Cost
Enginer Performance Analyzer check ignition & emissons control system= 43.00 L
Service Transer Case 31.00 L + 18.00 P= 49.00 (replace fluid)
Transfer Case Sensor + skid plate 100.00 L + 99.00 P= 199.00
Labor 174.00
Parts 117.00
Total 291.00 + tax

So then I take my truck to the dealership to ask if they can tell me if my truck needs a software update. The consultant guy doesn't know, so he walks back to ask a tech. He come back and tells me the only way to know is to hook it up to the computer. Which will be 89.00. So I tell the guy that I'm not going to pay him 89.00 to tell me I don't need an update. He then says the 89.00 includes the update and it would be at least 45.00 if it doesn't. It's according to how long it takes. Does anyone know if they can simply tell by the vin? I believe my dealership just replaced everyone with new employees.

The GMC dealership said it would be 30.00 to hook up and goes up from there according to how deep they have to go and how long it takes. 30.00-120.00. Probably 60.00 for just the transfer case update.

Surrounding dealership prices over the phone:
60.00
70.00-105.00
75.00
83.00

so the 4wd is working correctly now ?

the dealership can lookup your vin # into a computer to see if this update was a TSB for your vehicle..


T = top S= secret B = bulletin ... GM does this to screw the non GM repair shops ...

Just leave it alone. bring it to the dealership they will break something to teach you a good lesson on not having them repair it..

4wd has always worked until the service 4wd message appears. Only had my truck back for 1 day but no message, yet. It doesn't do it all the time, mostly when I'm on a dirt road but once the message appears it comes back often.

I think I will hold off on checking for a software update or if someone on this board can tell me I definitely need one. After much searching the internet, I can only find that the software update is needed for the 2003 models.