Ive had constant issues with my electrical 4x4 in my 01 blazer. After some research ive decided that im going to grab a shifter out of an old jeep. Mount it into my floor and complete the linkage to manually shift the 233 instead of the stupid tccm and encoder motor. As for the vacuum controlled jazz ill be putting in a posi-lok cable kit. I do have a couple questions i havnt been able to find first though
Am i able to just leave the tccm and the encoder motor unplugged? Should i cut the connectors or just tape them up?
Do i need to come up with some sort of switch the let the pcm know i have shifted it into 4lo or will the transfer case send a signal via another wire? Thanks in advanced! Ill post the build progress in another thread

 

One other thing you'll need to think about is that when you shift to 4LOW the trans gets a electrical signal that changes the line pressure in it. There's information on the S10 forum also about doing this.

 

this is what i was thinking, do you by chance have a link for the thread? I had a feeling the transmission needed a signal for the 4lo

ive been trying to find how to rig up a switch to let the transmission/pcm know. The only one ive been able to find was for an astro van, same wiring?


Apologies i said pcm but its a switch to the ecu, im just not sure if its needed, or what wires/terminals to hook up

 

I don't have a link but I know it's there somewhere. I took the easy route and used a 231 cable shifted model. I do have schematics for the wiring.

 

Sounds good, ill keep digging through the s10 forum. Ive found threads on switching the manual shift/posi-lok but none have mentioned altering the wiring or adding a switch. Ill try and dig further or maybe ill make a post over there

Currently im focuse on switching my np233 to manual shift, but if it ever blows ill be swapping to a 231. Could you link the schematics so i have them when i need them? Thanks for all the replies!

 

On connector 2 of the PCM, terminal 16, you install a N/O switch in line to the ground. The 4x4 low circuit consists of the PCM (powertrain control module), a TCCM (transfercase control module) and the circuit wiring. The TCCM controls the 4WD low signal on the signal circuit. When the operator selects 4LO, the TCCM grounds the signal circuit and the 4WD low signal voltage on the circuit changes from ignition voltage to zero volts. The PCM then compensates for transfercase gear reduction in the transmission output shaft speed (OSS) signal to adjust shift points, line pressure and torque converter clutch (TCC) scheduling.

 

Awesome thank you, thats exactly what i was looking for. By grounding out that wire with a switch on the pcm does that completely by pass the tccm? Or will i still need to have the tccm plugged in for it to work? My tccm is bad, reason im doing the manual swap

 

So if I took off my tccm and jus made my own shifter. How or what do i need to wire up the n/o switch to get my transfercase into 4lo?