45rfe to 545rfe Through Tuning

Printable View

03-20-2020
Evo8john

45rfe to 545rfe Through Tuning

Is there any way to enable the "5th" gear in the 45RFE trans through HP Tuners? Perhaps a segment swap with one of the 2001 vehicles? This is for a 2000 Jeep Grand Cherokee, and I would like to enable it for the slightly lower ratio for hopefully better highway fuel milage.

Thanks!
03-23-2020
Fast4.7

Quote:

Originally Posted by Evo8john

Is there any way to enable the "5th" gear in the 45RFE trans through HP Tuners? Perhaps a segment swap with one of the 2001 vehicles? This is for a 2000 Jeep Grand Cherokee, and I would like to enable it for the slightly lower ratio for hopefully better highway fuel milage.

Thanks!

As far as I know you will need to swap to a 01+ TCU.
03-23-2020
Evo8john

Interesting... Well I'm not going to take it that far for the wife's daily driver. Thanks!
04-21-2020
HemiX2

I am not sure if the HPT supports the 42RFE. I know it doesn't support my 06 545RFE. They started supporting the 545RFE in 2007. I also just found out that (at least) the 08 545RFE can be made into a 6 speed using the HPT. I am entertaining the idea of trying to install an 08 PCM/TCM in my 06 and see if it'll support it then. If the HPT goes by VIN number, I don't think it'll be possible. If it goes by the PCM/TCM that is installed then maybe.
04-23-2020
deltona1

Have a 2000 GC and been also looking for this.Does anyone know when and if HPTUNERS will implement this tcm protocols to be available ?Been also looking at ecu itself to see if there was any flash but didn't see only BGA processor inside.
04-24-2020
m_wakefield

It all goes by vin number. I'm currently have some major trams issues since the update on a 2008 ram that originally had the 545rfe. They change a bunch of stuff from 4.4 update and on that has made it almost impossible to do a trans swap and have anything work correctly.
08-11-2020
derek502

In the 2000-2002 Dakotas with the 4.7 we swap the TCM from a 02 Jeep GC and get the extra gear. I have one if you want to try it.
08-22-2020
HemiX2

Quote:

Originally Posted by m_wakefield

It all goes by vin number. I'm currently have some major trams issues since the update on a 2008 ram that originally had the 545rfe. They change a bunch of stuff from 4.4 update and on that has made it almost impossible to do a trans swap and have anything work correctly.

I am sure all of the factory stuff goes by VIN number but, the HP Tuner stuff, at least the PCM/TCM for the 545RFE, goes by the PCM/TCM that is installed. I've successfully installed a later model, used NGC4 PCM/TCM into my 06 Jeep with the 545RFE and now can access and modify all of the transmission settings with the HP Tuner. The VIN number and vehicle mileage need to be entered into the "new" PCM/TCM and a few other settings need to be changed with the HP Tuner. I've put nearly 1000 miles on mine since the changeover and am still trying to make the shift firmness a little softer. I already have the up and down shift schedules set the way I want them so all I need to do if figure out how to soften the shifts a bit.