Mercedes OM617 diesel to AW4 Cherokee automatic trans
 

Just got an AW4 transmission to make OM617 Mercedes diesel conversion some guys have been asking for. Got bellhousing to engine adapter back from shop today. The crankshaft adapter is the same as one we made for the wrangler automatic. Here is a progress so far.

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Hope to test fit to engine this weekend. :humm:

The AW4 is an electronically controlled tranny. In a Jeep it relies on inputs from the TPS and (I believe) the CPS to determine its shift points. So how are you going to provide or mimic those inputs?

we still have CPS in original location, hope to keep intact. If not we are looking at the RADesigns shift controller.

Doesn't it use the TPS as well? You going to try to adapt that somehow?

if it does we will adapt to TPS, the one we are worried about is if it reads RPM from distributor? If it does we will be forced into RADesign shifter.:humm:

IIRC it reads RPM from the CPS. It reads how far you put your foot in it from the TPS.
Thats really the only two things it needs to determine when to shift - how fast the engine's turning and how much throttle you're giving it...

Looking good! I'm glad to see progress on this! Keep it up! I look forward to hearing from you when mine's done! (First one of course!) Yes, this is Dean, the guy that called you monday and lit a fire under your...:moon:

As far as the transmission control, I can look up the wiring schematics on Mitchell On-Demand at work on monday. I told you about the little box with toggle switches I built for our Jeepspeed a few years ago, but talking with my wife, she prefers to maintain the fully automatic feature as well. So, I will be looking that up for my project anyway. Having manual control over the torque converter lock up may prove to be handy even with the TCM though...

So I did some research this morning, to keep the TCM happy all we need to do is mount the TPS. The TCM does not receive any signal from the CPS. The TCM has it's own speed signal coming from the transmission's output shaft. We couldn't ask for that to be much easier.:tu:

What year tranny & TCU are you using? I'm pretty sure that varies by year...

IIRC the 90 and earlier (ReNix) system uses the CPS for tach signal, because they have no VSS - the speedo is a mechanical drive off the tail housing of the tranny. The 91-96 ((HO) uses the VSS on the tranny tail housing, and I'm not sure what the 97-01 models use, but unless I'm mistaken they don't have a separate TCU - its functions are incorporated into the main ECU.

I looked it up for my '88. I can check the latter years tomorrow, I didn't even think to check them. There is an output shaft speed sensor in the aw4 specifically for the tcm. It has nothing to do with the speedometer. I didn't remember it was in there, if I were to have guessed I would have thought it needed the cps.