Alright my tranny took a crap bout 2 weeks ago, sun shell... go figure. Anyways now that i've got it all buttoned up and running again my 4x4 doesnt work. 4 button switch so I think I have the NP236? Anyways i can get it into 4x4 low but nothing else other than 2hi. I'm planning on having it scanned with a good obd 2 reader but its not throwing any codes on the dash as far as service 4x4. All it does is flash the button that I pushed. 4x4 low pops right in.

Wondering if when i put my transfercase back in I hurt that plastic (i'm assuming an actuator of some type) cylinder on bottom of transfercase.

Blazer is an 01 2 door 4x4 non zr2. Almost at its 150k birthday.

Any help would be appreciated.


Thanks

Nick

 

I would start by testing the resistance at the switch as well as at the TCCM. Details are in the thread below:
NV236 Wiring & Diagnostic Information

 

could it be possible that i couldve plugged the vaccum and speed sensor plugs into the wrong outlet on the transfercase thus creating my problem?

 

Doubtful. Is your 'Service 4wd' light illuminated in the dash?

 

No I've never seen it. Only code my scanner sees is P0155

 

A generic OBD2 scantool cannot read TCCM codes.

Have you tested anything that I have suggested?

 

I know it wont I meant as far as codes in general. The service 4x4 light is not on so would that mean that there isn't an issue that the TCCM is showing?

No I havent I'm not good when it comes to testing electrical's. I'm either going to have my buddy do it or take it to my buddies shop.

 

Well the 4x4 might actually be working. I can hear it engage but the 4x4 or auto 4x4 light flashes and doesnt stop. I did notice that the 4x4 low did the same thing but never paid attention to it before until now.

Is it possible that the transfer case will engage but the front axle isnt actually working?

 

It is possible that you somehow disconnected the vacuum line to the front axle actuator. There is an electric vacuum solenoid located on the firewall above the distributor. It should have the line from the engine to the bottom of the solenoid and the line out to the vacuum actuator under the battery on the side/front port. It should vent the line to the actuator when in 2HI and pull vacuum on that same line when in any of the 4wd modes.

 

Alright I will check that out. I do remember seeing a line that came out of the transfer case that looked like it was only a vent. Is that a vacuum line or is that just a vent? It was ziptied to the dipstick tube