Going from 4L60E to 4L80E and keep 4L60E segment, relays mod, any help?

I been searching alot about this but havent found clear information.. does any one can share or would like to help? if it posible with some kind of diagram or explanation of how to do it..

Why i would like to do this?? I just want to know how to do it in case i need it... maybe in a car that has been tuned already and it doesnt has a matching OS for 4L80E swap.. i will save time and will do it simpler

thanks really apreciate it.

Adrian

Quote:

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Originally Posted by 400ss

I been searching alot about this but havent found clear information.. does any one can share or would like to help? if it posible with some kind of diagram or explanation of how to do it..

Why i would like to do this?? I just want to know how to do it in case i need it... maybe in a car that has been tuned already and it doesnt has a matching OS for 4L80E swap.. i will save time and will do it simpler

thanks really apreciate it.

Adrian

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I'll locate a link for this for you...

Basically:
- use relay to invert 2-3 solenod signal,
- drive TCC PWM from either TCC ON/OFF or from TCC PWM gated thru a relay controlled by TCC ON/OFF (i.e. do not drive TCC PWM directly from TCC PWM),
- remove/ignore 3-2 control signal.

The reason you may want to drive a 4L80E from a 4L60E segment is that the car segment keeps the TCC locked on zero throttle, this gives a manual trans feel.

Quote:

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Originally Posted by joecar

I'll locate a link for this for you...

Basically:
- use relay to invert 2-3 solenod signal,
- drive TCC PWM from either TCC ON/OFF or from TCC PWM gated thru a relay controlled by TCC OB/OFF (i.e. do not drive TCC PWM directly from TCC PWM),
- remove/ignore 3-2 control signal.

The reason you may want to drive a 4L80E from a 4L60E segment is that the car segment keeps the TCC locked on zero throttle, this gives a manual trans feel.

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On the 2-3 solenoid signal... what signal do i invert? the PCM output signal from this wire? 2-3 solenoid?? what signal does it outputs? ground? or positive voltagE?

about the TCC i cant understand it 100%, maybe with a simple diagram

thanks a lot

If you can use a factory 4L80 calibration that is your best option, but that can be tricky to find a match back from a T42 that will be happy to run with whatever ECM OS you are running.

Quote:

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Originally Posted by 400ss

On the 2-3 solenoid signal... what signal do i invert? the PCM output signal from this wire? 2-3 solenoid?? what signal does it outputs? ground? or positive voltagE?

about the TCC i cant understand it 100%, maybe with a simple diagram

thanks a lot

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The PCM turns on the 2-3 solenoid by grounding it, see attached wiring diagram from 2001/2002 F-car.

If you compare the 4L80E and 4L60E shift solenoid truth tables, you will see that the 2-3 shift solenoid signal is inverted, see posts #1 of these threads to compare:
4L60E-Reference-Material
4L80E-Reference-Material

From post #12 in the second of those threads:

Quote:

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Originally Posted by joecar

To drive a 4L80E transmission from a 4L60E segment:
- discard the 3-2 control solenoid signal.
- drive the 4L80E 2-3 shift solenoid by using a relay to invert the 4L60E 2-3 shift solenoid signal;
- drive the 4L80E TCC PWM solenoid from the 4L60E TCC ON/OFF signal (discard the 4L60E TCC PWM signal), or see Alternative below;

Alternative (see posts #27 and #29 here, thanks GNXClone/Mike):
use the 4L60E TCC ON/OFF signal to control a relay which gates the 4L60E TCC PWM signal to the 4L80E TCC PWM solenoid:

http://forum.efilive.com/attachment....530998&thumb=1


TCC PWM warning:
the 4L60E may on occasion park the TCC PWM signal at 90% while the TCC is off,
this is the reason you don't want to drive the 4L80E TCC PWM solenoid solenoid directly from the 4L60E TCC PWM signal signal
(i.e. use a relay as Alternative says, or use the ON/OFF signal).

Note:
The F-car 4L60E segments keep the TCC locked on closed throttle decel (until vss goes below the unlock curve).
The Truck 4L80E segments (there are no 4L80E car segments) unlock the TCC on closed throttle.

To invert the 2-3 shift signal:
relay is connected as follows:
- the relay control coil is connected between 12V and the 2-3 shift solenoid signal from the PCM,
- the NC (off) relay contact goes to GND,
- the NO (on) relay contact goes to 12V,
- the swinging/gated contact goes to the 2-3 shift solenoid signal in the trans,

i.e. so when the PCM has the signal off (12V) the relay turns it on (GND), and vice-versa.


Also:
need to provide wiring to input 4L80E ISS signal into PCM.

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The important point here is that the car 4L60E trans segments keep the TCC locked when throttle is released (until VSS drops below the TCC Release curve)...

this gives a very pleasing manual trans feel and causes engine to make very nice exhaust rumble, and makes engine braking more intense.

does this method works on LS1B ECM and T42 ECM?? through the range of years?

Yes, these harness mods work for LS1A, LS1B and T43.