Allison reprogram review in Seneca

[SpeedyPete]

Hello Old Smokey, Can you share the process you went thru for adding this switch? I have a 2015 37FS. I have the OD button already but it sounds like this does not activate the performence mode in the tranny. I appreciate the help here!

[Old Smokey]

Yes. I installed a control wire in pin location 42, ran the wire through the firewall into the cab, connected it to a single throw, single pole toggle switch, and connected a control switch to a signal source. Pin 42 is vacant and filled with a plastic dummy plug like many of the unused pin locations in the TCM connector.

You are correct. The O/D lock out connects to pin 61 and is independent of the mode selection function. I also have O/D lockout which was installed by Freightliner.

The Allison TCM is mounted on the drivers side firewall at the top, just under the hood. It’s very easy to access.

[SpeedyPete]

Old Smokey do you happen to have a picture of the TCM with this wire pointed out? Just want to be armed with all the info when I get home this eve to look at mine. Maybe a pic of your switch as well if possible. I really appreciate the incite here mister!

[Lost and Found 2022]

I have a 2015 HJ and had the transmission reprogrammed by Allison. I also had Cummins do the uprate. Huge difference! We will be traveling primarily in the mountains so no need for eco mode. Best $600 I ever spent. My thanks to Robbyr for the guidance. Glad yours worked our as well. Totally different machine after the changes.

[Old Smokey]

Added a label to my switch.

[SpeedyPete]

Would it be possible to see the TCM wiring?

[SpeedyPete]

Old Smokey, Is the control wire a simple keyed 12v power wire?

Thanks

Pete