This post is so chock full of information it is offerred unedited and in its entirety.
4L60E REMOVAL / SWAP
Subject: Re: Transmission removal/swap *IMPORTANT NOTES*
From: "Mitch Posner" <Grace_Industries@email.msn.com>
Date: Sat, 26 Oct 2002 00:16:44 -0400
X-Message-Number: 1
Peter Cordes informed the list the '95/'96 4L60E transmissions are
different that the '94 transmissions. There is a slight difference, but
an important one. It has nothing to do with having an OBDI or OBDII
system. Specifically, it has to do with the TCC PWM solenoid. The '94
transmissions are the only ones that don't have them. However, if you
choose to install a '94 transmission a '95/'96 Impala, you will receive
a check-engine light because the pcm is looking for that solenoid which
is missing in a '94 transmission. You really won't notice any
difference, but having that solenoid is supposed affect/help the torque
converter somewhat. To add the solenoid, it requires the '95/'96 style
internal transmission harness (quick swap, plug and play) to
interconnect everything back together. I personally cannot tell any
difference with the solenoid, however here are the steps necessary to
install a '94 4L60E into a '95-96 9C1/Impala SS:
1) Install a '95/'96 design transmission wiring harness
2) Install a new TCC PWM solonoid (since the '94 transmission lacks one)
3) Understanding Peter's post, the reprogramming he suggested should not
really be necessary since the '95/'96 pcm is already preprogrammed for
the TCC PWM solenoid.
Here are some alternate methods I propose:
1) There seems to be two ways to accomplish the above case install. One
is to install a new wiring harness as well as a new TCC PWM solonoid.
(No reprogramming should be necessary since the '95/'96 pcm is already
pre-programmed to look for a TCC PWM solonoid with its correctly matched
wiring harness).
2) The other is not to install a new wiring harness nor ever installing
the TCC PWM solonoid. Instead, simply reprogram the pcm and program out
the code for that solenoid (this is exactly the '94 OEM setup and will
match the '94 transmission install).
These "choices" then become confusing because Peter Cordes proposed:
1) Install a '95/'96 design transmission wiring harness.
2) Install a new TCC PWM solonoid (since the '94 transmission lacks
one).
3) Reprogram the pcm (for what(?), I don't understand).
1) Since the '95 pcm already contains the program function for the TCC
PWM solonoid, why reprogram the ('95) pcm for the '94 transmission after
performing a transmission wiring upgrade for it?
2) Why not just program out the TCC PWM code out of the ('95) pcm to
avoid the MIL/CEL light? Wouldn't it then be fundamentally mated for a
'94 transmission? This would not require a wiring harness upgrade in
this case
and the net effect would then resemble a '94 vehicle.
I welcome your comments
Mitch Posner
'96 383 BBB
'95 9C1