Engine/Transmission (1994 - 1998) 47RE Electronic Failure

[TBora]

I'm looking for a 12 valve to use mainly for offroad exploring/camping. My trips will take me 50-100 miles off the beaten path. I want super reliablity (or at least something I can fix in the field).



What happens to a 47RE if the "computer" fails? I want to know what happens if the electrical portion of the trans completely quits; is the truck immobile or can I limp back to base? Can a spare "computer" be installed in the field?



I have my eye on a 1996 and an early 1998, but there is one 95 that may also work (RH).



Thanks All

 

[Allnew2Me]

My understanding is that if there is an electronic fault, such as when my governor solenoid and transducer went out, the trans goes into "limp mode". On mine it started in second gear all the time. It did upshift but with other malfunctions it may just stay there. These parts are in the valve body which can be field serviced as well as the output shaft speed sensor which is on the outside. The transmission is controlled by the PCM which is located under the hood at the firewall on the passenger side. If the PCM were to fail I think you might have other problems besides just the transmission. It also could be replaced as it is easily accessed. Valve body issues are fairly common but I don't remember reading about many PCM problems, someone else may have more info on that.

 

[Missouri Mule]

I haven't heard much about PCM giving any trouble but the torque converter and TPS ( throttle postion sensor) are the main problem areas, there are things you can do before they cause problems. Sometimes the bands come out of adjustment.

 

[McLaughlin]

From what I understand, and I could be incorrect, the electronics control of the pre-24 valve Cummins is pretty limited. The engine functions are not electronic controlled for the 97 and earlier(not sure about the 98s) so losing a "computer" should have no impact on engine operations. Regarding the transmission, I'm sure the computer controls the torque converter lockup but am less sure of the rest of the transmission operation. A quick review of the 97 service manual indicates the "computer" controls a governor solenoid which is involved with 3-4 shifting and 2-3 shifting through a series of valves so there is at least a potential (I don't know how great it is) that if the "computer" starts acting flaky you could have some problems with 1st, 2nd, 3rd , and overdrive shifting.

 

[San Felipe Bob]

100 miles?

If the electronics had me worried (which they don't)

I'd save myself the extra grey hairs and go for a manual trans.

If you have a manual transmission you can manually wire the fuel solenoid open and push start the truck without any need for battery power.

If a manual trans starts going out you can limp alot longer than with an Auto. .



Just my 2 cents



SFB

 

[ScottLewis]

I had a wire pull slightly out from the PCM connector on my '98 that caused the 47RE not to shift out of first. I replaced the PCM and had it reflashed without fixing the problem. Because everything I read indiated that it was a speed sensor problem I then spent about 3 1/2 hours tracing the wiring until I found the loose wire.



Bottom line, the PCM controls a number of functions of the 47RE.



Dan

 

[TBora]

SFB:



Yep, I want the manual trans, but my wife has me over-ruled!!!