Hey guys,

The jeep is at it again. On Monday I started having transmission problems, get ready to go to work and the TCM is in limp mode. Pull a code and its P0605 (Internal Control Module Read Only Memory) on the TCM. I grabbed a TCU from the local pick n pull from a 2003 Jeep grand Cherokee that had what i believe to be a 545RFE and its no longer in limp mode but its behaving exactly the same. I have access to a SnapOn Solus Pro and got to looking at the TCM Data and see a handful of oddities. I can talk to the TCM, but it has no idea where the PRND21 shift lever is, all 5 pressure switches are "closed", fluid temp is 1024, and line pressure is 0. I just ran through the harness and everything is nice and loose, does not appear to be rubbing anywhere. Does the TCM really just die like this? I just Ebayed a new one so hopefully it'll be here next week.

When i have the 03 grand cherokee TCM hooked up it shows all 5 pressure switches as "open", but engine RPMs at idle is 0, line pressure 0, Temperature is 1024, and doo doo lever is all ??? as well. Let me know your experiences

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05 CRD Sport - GDE EcoTune - Samcos - EGR Delete & Elbow kit - ARP Studs - Airtex E7181M

Yes, they do fail like that:

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I don't recall anyone using a TCM from a Grand Cherokee. Chrysler did introduce the 545RFE early in it's life cycle into some vehicles and continued to call it a 45RFE by limited it to 4 gears through the TCM. This could cause some funky incompatibilities when it tries to talk to the ECM of a 5 speed vehicle. Not sure if the GC was one of these.

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1 used TCM and its back on the road. I should have just listened to what it was trying to tell me.

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05 CRD Sport - GDE EcoTune - Samcos - EGR Delete & Elbow kit - ARP Studs - Airtex E7181M

Did it have to be programmed by the dealer?

I don't think it requires any programming.
The TCM will go through a learning process for the first couple drives.

I put a used 2005 Ram 5.7 Hemi TCM in mine. No programming necessary. Although it does have different shift points which required me to reprogram my right foot.

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U.S. Army Retired

For a used module generally not, but if there's a significant difference in wear on the donor vehicle it may have a period of adaptation during which time it may feel a bit strange. When mine failed I got lucky and managed to pick one up locally from a vehicle with similar mileage. The difference was very subtle.

Not sure if the same applies for a dealer supplied refurb.