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THEFERMANATOR
September 23rd, 2009, 05:46 AM
What are others doing as far as tow/haul mode on engine swaps? I know GM hooked the switch to the BCM and then transmits it over the class 2 data bus to the ECM or TCM to engage it it. Has anybody found a way to engage it without the BCM? Is there a simulator or something out there that will act as the BCM? I have everything worked out on my DURAMAX/allison swap except for this roadblock and I am trying to get past it.

THEFERMANATOR
October 8th, 2009, 02:09 PM
Does anybody know of any companies out there that can make a box that can simulate a class 2 data bus signal to mimic what the BCM would send to engage tow/haul? I've found one, but it is pretty pricey and I don't know if it would interface with my ECM and FICM.

THEFERMANATOR
October 20th, 2009, 11:53 AM
I finally got it to work, and was able to get an indicator as well. After some fiddling I got the BCM wired correctyly and it engages tow/haul just fine.

joecar
October 20th, 2009, 02:00 PM
Good job... :cheers: ...I was following along, but I didn't know any answers.

dbunyip
January 14th, 2010, 05:21 PM
Do you have any info on how you got this to work?

THEFERMANATOR
January 29th, 2010, 08:35 AM
I ended up wiring in the BCM and it's power and ground circuits. Hooked in a momentary switch to ground and installed a resistor in the PASSLOCK side. I also took my old cluster and cut the logic module out of it and hooked it up to an LED to have an indicator for tow/haul mode.

Cougar281
January 29th, 2010, 09:17 AM
If you where to run a 01-02 TCM OS, you could run a momentary contact button to the TCM and a LED, and do without the TCM....

THEFERMANATOR
February 3rd, 2010, 06:43 PM
On an 01 you use the momentary to the TCM for overdrive lockout, but you still need the BCM for tow/haul mode no matter what year ALLISON your working with.