2000 jimmy 4x4, new vss,new ignition,new pcm
Checked for continuity between green amd purple wires on pin 29 and 30. Have scanner and live tables.Have seen the vss signal twice fornabout 2 seconds. Checked for voltage from pcm d on purple black wire. Found none. Checked my fuses all look good. Had about 7 codes. Now mainly getting 2 or 3 p1860 p1840 and another tcc low voltsge one. Really dony know where to go from here any suggestions anyone?wont shift into 1st. Only jave 2nd and 3rd. And getting no vss signal.have tried 3 dofferent ignitions and vss,and replaced multifunction switch unrelated.

I checked voltage coming out of pin purple and black wire and green input on pin 29 and 30. I compared to a working blazer. His was showing .6 to .3 it would fluctuate. Mine showed a -.3 with the multimeter which i think indicates reverse polarity, it never moved no matter the condition. Any help please?

Both pin 29 and pin 30 had continuity alll way too vss sensor

 

Not sure about the issue, but someone will say something soon.

 

Getting TCC solenoid low voltage together with a missing VSS signal could be the power supply problem.

 

Do you know where i would check the tcc voltage,where does it it?and if the tcc splenoidnhad low voltage would that make vss not read?

 

I checked the ohms and its showing 0, on pin 29 and 30,with vss disconnected, so am i right in thinking the 2 wires are touching in the harness?

 

2000 blazer 4x4. Got it for 350,previous owner had new transmossion installed,afterwhich he had no speedo,and limp mode,abs light on and about 10 codes. Since then ive replaced ignition and vss. I checked all fuses and there all good. I determined the vss wires were pinched or touching somehwere with mulimeter.I ran new wires from c1 blue pin 29 and 30,to the vss. I now have a perfectly functioning speedo. Still starts out in 2nd. And will not shift on its own. It now only throws 3 codes. I need the wiring diagram for the transmission harness to the pcm.I have a feeling other wires are pinched and i want to rewire the harnes to pcm. Also does anyone have any tricks for removing transmission harnes plug,im having trouble getting it off.

 

Send up the bat signal for Transman!

I'm sure he'll help you out once he shows up

 

Now that you've posted the codes:

P0740 - Torque Converter Clutch Circuit
P0753 - Shift Solenoid A Electrical
P0785 - Shift Timing Solenoid
P1860 - TCC PWM Solenoid Circuit

In each of the diagnostic charts, it lists these specific codes as all of these codes could be caused by a blown CLSTR fuse.which is located in the IP (instrument panel) fuse box accessible with the driver door open by removing the cover on the end of the dash. I know you mentioned checking the fuses, but the IP fuse box is often overlooked. If that fuse is good, then you need to test for power at the appropriate pin at the transmission.

Before you say "but why is my VSS out", one problem at a time and the bulk of your problems very well could be related to one simple to fix cause. Once we get through those codes listed, we'll tackle anything else remaining.

 

Yeah like i said checked all fuses,have power to all them. The wires were smashed from previous owners transmission install. Im assuming the brown tcc solenoid control wire has been smased as well.I found the schematic amd plan to make new harness amd rewire tomorrow.

 

Here are a few of the schematics I could find in the time I had to look:

Connector Pinout for the plug on the Transmission

4L60E Valve Controls Schematic

4L60E Pressure Switch & PNP Switch Inputs

They are spread all over the place in the FSM (same for AllDataDIY). You may just want to get yourself an AllDataDIY account & subscription to your vehicle if you intend on keeping it for any length of time.