05 silverado service 4wd

[steves3424]

I've got a 2005 1500 Silverado Z71 Autotrac 4WD.
When I push 4hi to engage the 4wd, the lights blink for about 10 seconds then I get the service 4wd message. I can hear a slight click when I do this, but the front wheels are not locking in.
When I push 4lo with it in neutral and at a standstill, i can hear the 4lo lock in. The front wheels do lock too, but it continues to blink 4lo.
I've spent many hours on this forum looking for others that have had this same issue and had come to a conclusion that it was my encoder motor - especially since it is very common with this year of truck. I replaced it last night and let the truck sit all night with the 4wd and TREC fuses pulled, along with the negative terminal pulled from the battery.
When I started it this morning, I had the same issues.
The fluid in the transfer case is fine and at proper level.

Any other ideas???

I do know that it is not my switch. I used to have a 1999 Silverado Z71 and had problems with the switch. I ended up just resoldering the pins and it worked great.

[j cAT]

Originally Posted by steves3424

I've got a 2005 1500 Silverado Z71 Autotrac 4WD.
When I push 4hi to engage the 4wd, the lights blink for about 10 seconds then I get the service 4wd message. I can hear a slight click when I do this, but the front wheels are not locking in.
When I push 4lo with it in neutral and at a standstill, i can hear the 4lo lock in. The front wheels do lock too, but it continues to blink 4lo.
I've spent many hours on this forum looking for others that have had this same issue and had come to a conclusion that it was my encoder motor - especially since it is very common with this year of truck. I replaced it last night and let the truck sit all night with the 4wd and TREC fuses pulled, along with the negative terminal pulled from the battery.
When I started it this morning, I had the same issues.
The fluid in the transfer case is fine and at proper level.

Any other ideas???

I do know that it is not my switch. I used to have a 1999 Silverado Z71 and had problems with the switch. I ended up just resoldering the pins and it worked great.

if you looked thru these 4wd issues you saw it is recommended to pull the drive train codes then post back...

replacing parts with out troubleshooting , is like gambling you usually loose.

use the diagnstics , to not waste time/money............