[Mark Ralph]

I have a 2005 DuraMax 4x4. I took my truck to a local mechanic because the 4x4 would not engage. He cleared the codes and the 4x4 started working again. Now it does'nt engage again. What could be wrong that would place the codes in preventing the 4x4 from engaging?

 

[02lb7dmax]

it prop has a safe mode that it goes into when the code is active and you cannot fix it by just clearing codes the code is putting it into a safe mode so that system cannot be damaged. What code was it ? that would narrow down the problems more! let us know:drink

 

[Dcattech]

^^Like stated above, we need to know what code you have. You could possibly have one of a multitude of issues, i.e. bad encoder motor, bad front diff actuator, bad selector switch, faulty tccm, one other thing to check is the grounds on the frame under the front drivers side door, make sure they are clean and tight.