Just bought a used 01 Blazer ZR2 4.3 4X4.

With it in non , or auto AWD mode, cold or hot, my "Service 4WD" MIL comes on, and stays lit. and I cannot get any 4X4 action when trying to engage 4Hi/4Lo. The Auto $X$ light does illuminate, but cannot shift into 4Lo or 4 Hi.

I DID see a vaccuum hose appears cut or torn wedged between the NEW transfer case & cab.


Any ideas.

My first Chevy.
Was a Dodge man.

Help?

 

repair the hose and check all hoses and fuses

 

Have a look around a bit. Search for NV236 or NP236 as that is the designation of the transfer case you have in your truck. As I posted in another thread to correct you, you will need an enhanced scan tool to read the codes stored in the TCCM. If your 'service 4wd' light is on, you need to read the codes to determine what the TCCM has stored for a code.