47RE Torque Converter Lockup Adjustment

[Tim5.9]

I added a tc lock on 47re caused my throttle to be cut to about 2k rpm and i lost speedo. Had good ground and tapped correct wire. If engaged in 2 or 3 it wouldnt lug at all. 

[dieseled]

On ‎3‎/‎16‎/‎2018 at 8:19 AM, Dynamic said:

It is my understanding that Chrysler received the engine assemblies from Cummins complete with electronics (APPS, ECM, etc.), and ready to drop in as a pre-configured unit. The ECM simply outputs a 0-5V TPS signal (based off of the APPS signal the ECM sees) and crank sensor signal (to reference engine RPM) to the PCM for use in controlling the transmission

 

On ‎3‎/‎16‎/‎2018 at 8:19 AM, Dynamic said:

 

There are a myriad of different - let's call them "anomalies"...to be polite - that I would find "work-arounds" to if I was a smarter guy. This is definitely one of them. I have, on one truck that I built a transmission for, played around with some fixed resistors on the TPS signal line to delay the shift into OD, which did work, but that truck was a 12 valve with a 47RH, so I was just manipulating OD and TCC lockup. I would surmise that the same could be accomplished on a 47RE with some ingenuity

On ‎3‎/‎14‎/‎2018 at 8:15 PM, kzimmer said:

Below is a screenshot of the factory service manual. Not shown in this screenshot is the APPS, which is wired to the ECM. It looks like, for some reason, the APPS (TPS) signal is repeated by the ECM and retransmitted, hard wired, to the PCM. I have no idea why they chose to do it this way instead of sending it over the data bus. I also don't know how it's scaled. Assuming 0-5 VDC, just like the ECM. Can anyone verify? I'll measure if need be.

 

 

I did this to" fix" some "anomalies" that my truck experienced at specific apps - throttle positions relating to shift points and lock up points about 15 years ago , fixed them

As I understand the ecm may be changing the apps signal just enough for the pcm to cause the problem  , tying the apps to the pcm before the ecm is a purer signal

 

Also wondering if maybe if you haven't recalibrated your speed  tire size ,maybe that could cause shift - lockup issues   

4th Gear Hunt Fix (1998-2002) v1.0 (1).pdf

Edited March 6, 2019 by dieseled
misspelling

[kzimmer]

This was almost a year ago. I broke the truck shortly after this post was started and haven't fixed it yet. Haven't done any work with the lockup. Very interesting article though, I haven't seen that one around, thank you for the info.

 

As someone that works in the electrical controls industry, it is not standard practice to run one analog device to two separate analog inputs on two separate measurement devices. Will it work? Probably. Is it a good idea? Likely not. I think there is probably a reason the ECM repeats the signal to the PCM, instead of paralleling the two inputs to the one sensor.

 

I was able to watch the throttle position % on IQuad and recreate the problem every time. I'm confident a dirty signal didn't cause my problems. 3.54 gears, 35" tires, and a non adjustable PCM caused my problems. Fixing any one of those 3 things would help my situation. I'd prefer #3 but as far as I know it's impossible.

 

My truck is also calibrated for tire size. I could move the lockup and 4TH gear shift if I lied to the truck about tire size. But then my speedo would be off.

To add:

I just saw the part where they say to tie the apps signal return wire to ground. Ugh! No! Wtf ATS?