47re imputs for 97 ECU- to get it running

AsTroSS

AsTroSS

problems start @80 psi
What input sinals from engine,tranny and rear axle is needed for 96-97 ECU to get the 47RE fully functional

I am thinking

1. from engine : speed and TPS signal or potentiometer trick

2. all signals from tranny itself

3. do it need vechicle speed signal ?

what else?
 
Why No reply?

It can be for 2 reasons:

1. people do not knew
2. people do no want to chare the information
 
pretty sure your gonna need vss from the speed sensor in the rear axle and your also gonna need output shaft speed from trans as well as the lever position switch (these are not part of the round valve body plug)
 
Do they really need two similar signal : vechicle speed signal and output shaft speed?
 
Definitely need the output shaft speed sensor, believe that is what the PCM uses to determine how much governor pressure that is needed.
 
Last edited:
tractorguyacb said:
well mine wont shift right if either sensor is unplugged so id imagine so
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Is your truck '98 , vvs from rear axle, not from transfercase?

My friend Wagoneer made the test, he disconnect the vechicle speed sensor and run the truck ( '97 Ram 2500)

Result : speedo not functional , but tranny will change the gears and lockup is functional - > decition this sensor not needed
 
So the minimum list will be :

1. all 47RE internal sensors and solenoids
2. battery voltage
3. TPS
4. engine rpm

:poke:
 
zstroken said:
Well it might need the Tcase output speed sensor, I forget if I pulled that.
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.. but up to 98 transfercase output speed sensor is vechicle speed sensor

From 98 no transfercase output speed sensor , speed is calculated from rear diff ABS sensor (tone ring)
 
AsTroSS said:
.. but up to 98 transfercase output speed sensor is vechicle speed sensor

From 98 no transfercase output speed sensor , speed is calculated from rear diff ABS sensor (tone ring)
Click to expand...


Correct, however the 97 and 98 PCM's are different.

So each PCM might actually need to know vehicle speed to provide the correct governor signal.

Matter of fact somewhere along the lines I remember the PCM has 4 governor algorithms.

WOT
4low
COLD
Normal

this is all from memory.
What the PCM does without the vehicle speed signal is a mystery to me.
 
Yes I read aswell the governor have 4 maps.

But do not forget, the ECU (PCM) have transmission output signal, this way it should knew how fast truck is going, the VSS or tone ring info just doubles it or triples


Maybe ths VSS signal is needed to detect 4wd low?

I do not see any other way to identify 4wdlow. If the transmission output speed and Vechicle speed is different the PCM detects it as 4wd low?
 
WOT and Normal - can identify by TPS signal


COLD- from transmission temp sensor


4WD low is still mystery
 
AsTroSS said:
WOT and Normal - can identify by TPS signal


COLD- from transmission temp sensor


4WD low is still mystery
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4WD would be like you said, difference from transmission output speed sensor, and either the VSS in the tcase on the 97 and older or the vss in the rear axle on 98+
 
AsTroSS said:
But in 2wd application VSS is not needed?
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I believe I saw on the older 47RE there was a VSS sensor on the OD section. I could be wrong. Look in the service manual it should show you a wiring diagram and call out if it is different for 2wd or not.

2wd VSS would never see the slower speed so the PCM could be programmed but would never need it.
 
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