More stuff on swapping a 4L60e for a 4L80e

[Shannen Durphey]

Doug Bazarnic wrote:

> 
> Ahh, I see.   My manual is for my '95 truck, 


Also, there are two different design pressure solenoids.  Calibrations
must match solenoid type.  Again, break year is 94.
> 
> So to be absolutely certain, beyond any doubt, that you
> >have a pcm which will work with both transmissions, get the #16197427
> >part.
> 
>   Where do
> you find this info?   

Ummm... I have connections.  If you can get a copy of the Snap-on Prom
reference guide, it has some of this info.  Also, a good working
relationship with a GM parts man will help immensely.

>So, what is the proper calibration code for the 3/4
> ton 5.7L w/4L80e & 3.73 rear gears?
BXSJ/4933 GM part no 16244933

> >
> >Can you use the 2 "extra" wires to connect the "extra" trans speed
> >sensor?
> 
> Here are the differences that i see according to the pinout tables in my
> service manual:
> 
> Pin             4l60e                   4l80e
> B10     Cruise Signal                  NOT USED    ** see note
> E2      3-2 cntrl solenoid             NOT USED
> E10     TCC solenoid cntrl             Idle speed actuator control 
                                         (7.4 Liter only)
> F2      NOT USED                       Input Speed High
> F3      NOT USED                       Input Speed Low
> 
> Okay, here's some details:  the service manual lists, for these two
> (actually 3, as one is diesel) computers, one is labeled 4.3L, 5.0L, 5.7L
> (C/K) 4L60E and the other is listed as 4.3L, 5.7L 7.4L (C/K) 4L80E.
> 
> ** note:  In the table of pinouts of the PCM, the 4L80E table shows B10 as
> not being used, however, the wiring diagram does indeed show it going to:
> Cruise Control  Switch <- 396 Lt Blu / Blk
> 
Does that manual have section 8A, electrical diagrams?  Those are the
most accurate, and any others can be out and out wrong.  

> It looks like I could yank E2 and move it to F2, and move E10 to F3 and I
> wont have to run any extra wires at all.
> 
> The connectors on the tranny are as follows:
>
Is this the way the chart should appear?  It didn't come through
correctly. If so, looks good.  Unused terminals can be removed or
sealed with silicone.
 
> Pin        4L60E                            4L80E
> A         1-2 Shift                       1-2 Shift
> B         2-3 Shift                       2-3 Shift
> C         Pressure Solen. High            Pressure Solen. High
> D         Pressure Solen. Low             Pressure Solen. Low
> E     Both Shift Slnd, TCC, and 3-2 high    +12 volt ( ign. crank on)
> L         Fluid Temp High                 Fluid Temp High
> M         Fluid Temp Low                  Fluid Temp Low
> N         Range signal A                  Range signal A
> P         Range signal C                  Range signal C
> R         Range signal B                  Range signal B
> S         3-2 Cntrl Solenoid Low          TCC PWM Solenoid
> T         TCC Solenoid (low)
> U         TCC PWM Solenoid
> 
> It looks like pin E is the same for both looking at the wiring diagram, as
> it's the +12 side on all the solenoids in both cases.
> 
> It looks like U goes to S and the old S & T wires will become my Input
> speed low & high wires.

Where I fall short is knowing things like speed signal lines should be
shielded, especially for sensors that are sensitive to electrical
noise.  Thanks Pete Hipson.

> Depending on what the 4L80e will cost me, I may purchase a lower gear set
> for the tranny.    Then again, I don't know if it's really necessary, as I
> can leave tracks from here to wazoo... :)   I have a video of me leaving
> tracks over 85' long -- I can turn it into an .avi if you wanna see.
> 
There's an internet burnout page at
http://uts.cc.utexas.edu/~mwilgus/burn.html .

> One other concern:  Where / how is the vehicle speed stored?   I have 3.73
> rear gears and I don't know if they figure vehicle speed via the ECM or
> gears in the tranny or what?
Good question.  Speed used to be calibrated in the DRAC, a small white
box under the dash, and  the signal sent to the ECM was 2000
pulses/mi.  I've noticed that 93+ vehicles with the PCM have the
DRAC's divide ratio set to one, that is one pulse out for one in. 
Calibration factors must now be stored in the prom.  
Shannen
>  Thanks for all your help,

>