"Service 4WD" Message '05 Silverado
 

Need some input folks. Earlier this week my truck threw up this message on my dash and it has not gone away. The truck has push button 4wd and with this message up I can't engage 4wd at all. Is there anything in particular to look for? I have not tried disconnecting the battery yet. I'm not sure if that "trick" still works on newer vehicles or not. The truck sees very limited 4wd use and has roughly 80k miles on it.

Any ideas on what may be wrong?

Thanks in advance.

Re: "Service 4WD" Message '05 Silverado
 

there is an electric actuator that shifts the transfer case. When you try to engage the 4wd, what does it do? If it is an actuator problem, the lights on the shift buttons will flash until it engages.

Re: "Service 4WD" Message '05 Silverado
 

The switch going bad is pretty common.

Re: "Service 4WD" Message '05 Silverado
 

It doesn't do anything. No flashing lights or anything.


I've come across this answer as well while searching the internet, but how could I tell if the switch was bad?


Thanks for the input. Anyone else?

Re: "Service 4WD" Message '05 Silverado
 

In an 05 the most common failure is the encoder motor sensor. The switches mainly plagued the 02 and older models. If you can get the codes out of it with a tech 2 you will most likely have a c0327 encoder sensor circuit code in it. The most common repair is replacing the sensor in the actuator.

Re: "Service 4WD" Message '05 Silverado
 

Thanks for your reply Josh. Can the sensor be replaced fairly easy or is it a dealership type job? Any idea what the sensor may cost?

Re: "Service 4WD" Message '05 Silverado
 

BTT updates?

Re: "Service 4WD" Message '05 Silverado
 

Mine did this twice it was just snow and ice build up and went away.. Do a power cycle. Turn ignition on and off 3 times but not to start position..
Hope it works..

Re: "Service 4WD" Message '05 Silverado
 

I just had to put a switch on the dash in mine last week.

Re: "Service 4WD" Message '05 Silverado
 

I too had the same problem on my 05 z71 and did all the trouble shooting that was advised. I even bought a new dash switch but no luck. Anyways to make it short it was the encoder and a friend that does work on the related issue, told me it was very common.

Re: "Service 4WD" Message '05 Silverado
 

Mine said it once or twice in hyway with lots of snow. Just ice and snow in there maybe....

Do the 3 key turns power cycle.

Re: "Service 4WD" Message '05 Silverado
 

Hello everyone. I posted on this subject before and was confused with the problem. I replaced the encoder, and everything was back to normal. So this spring, i was driving with my family on the highway and we ran into a rain storm alot of water on the road. The service 4wd message came on all of a sudden. We stopped to put gas, turned off the ignition. I was hopeing it would reset, but no such luck. Well we hit the road again then the transfer case seemed to be shifting on its on while i was driving. Anyhow, to make a long story short i realized that either the accuater or one of the electrical parts of the 4wd at the bottom is getting wet and and possibly shorting out something, making it do strange things. What i did was took out the fuse in the fusebox in the cab and the one in the fusebox under the hood. It all went back to normal after everything got dry. So everytime it rains heavy i pull the fuses and put them back after the rain"s gone, all back to normal. Haven"t had time to get under and investigate the problem, but if i find something i"ll pass it on. Just a thought.

Re: "Service 4WD" Message '05 Silverado
 

^^^^^
encoder sensor getting water in it. The TCM tries to bring it back to the position requested by dash switch. Time for a new sensor again. This time seal it up good

Re: "Service 4WD" Message '05 Silverado
 

How would you seal it?

Re: "Service 4WD" Message '05 Silverado
 

Here is a nice view of the part.


http://www.archivedsites.com/techcon...nd-sensor.html

Desert

Re: "Service 4WD" Message '05 Silverado
 

I have the same year model and was having the same problem. It would kick mine out of gear after the service 4wd code came on it got so bad. Was thinking it was the switch in the dash but it ended up being the motor inside the tranfer case.

Re: "Service 4WD" Message '05 Silverado
 

EDIT - oops .. I didn't see the original posting date.





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