jimmyblue

iTrader: (11)

Looking for a way to access the "performance mode"
shift tables on an F-body. I think this is a leftover
from other vehicles that offer a select switch. The
Helm manuals for my car have a lot of "Not Used"
pins on the PCM and no pin clearly named to be a
"Performance" or whatever. Does anyone know how the
"Tow/Haul" select gets fed to the truck PCM? Like is it
a switched +12 or Gnd straight to the PCM, or is it fed
over the serial bus from the BCM, etc.? If there was
a PCM connector pin assigned I would like to try the
same one on my car (if it's a "Not Used" or something
with a name I don't recognize) just to see if it does
what I want (two separate transmission profiles for
casual and aggressive driving). Conn/Pin # and the
electrical info would be great if it's a straight wire job.

Hit Man X

Are you asking how to add a "Performance Mode" to your F-bod?

jimmyblue

iTrader: (11)

That's the goal; just hate to see those extra shift
tables sitting there doing nothing. There was a couple
of years (in the LT1s) where there was this switch.
But nothing in the LS1 FBodies (at least, nothing
documented). So if I can find out what the trucks do,
maybe it will uncover something (or not).

For example I might like to have a few hundred RPM
higher shiftpoints and higher pressures for the track
than I'd want to beat on the car with full time, and a
switch is nicer than a laptop session....

Blown Yellow

I am not sure if I miss read what you were saying but there is an option on some 4l60e Ls1's that has a performance shift mode. Unless I am completely losing it I test drove a 98 convertable ram air T/A that I totaly remember playing with the peformance shift button on. It was located on the drivers side center consol beside to shifter.

I can not tell you if the output is there on a non factory equipted car but I myself do use the tow haul in my silverado as a "race mode switch" to increase shift points and firmness when activated. It really is a great way to smooth out the shifts in a daily driven hotrod, and it is something that is often overlooked by tuners.

Chingon

iTrader: (1)

Could the tow/haul button somehow be set up in such a way that you could have different timing profiles?
The Nelson tune has the dual octane option, and I've been wondering if you could, for example, have it start up on 87 octane table, then when you hit the tow/haul button, it turns on the 93 (or 91 for Californians ) octane table if you so choose.
Or perhaps make this your nitrous activation switch??
If there has been a thread about this I must've missed it

deezel

Nope. The timing tables are the same. Dual octane tuning just means that the low octane table is set low enough to be safe for 87 octane, and the hi octane table is more aggresive for 93...
Tow/haul affects shift points, shift firmness, upshift torque reduction, and TCC lockup points.

I recall one thread where someone mentioned disconnecting the tow/haul button wires from the factory harness and converting it to a nitrous activation button.

L-EATER

iTrader: (2)

To answer the original question, yes those signals travel thru the bcm over the serial data wires. I am pretty sure there is no easy way to do it. I briefly looked at hooking up the tow/haul on my work truck, but I don't even have a bcm so i just gave up.

mudz5.3

I did ask this question awhile ago about disconnecting it and using it for a purge button, but I didn't get an answer. So I am wanting to find out, kinda the same, well the wire out of the pcm atleast.

jimmyblue

iTrader: (11)

OK, in that case I guess I'll be interested in the
BCM connection too. Just in case one of the 5
or so "Not Used" terminals on that puppy end up
to be qualified but unemployed....

deezel

Ok, I checked my service manual for 2000 truck.
The tow/haul switch does go to the BCM. The BCM then sends info to the PCM over the data bus. The PCM pins that go to the BCM (data bus link) are 58 and 59 on the blue connector. I can check later tonight about which pins are used on the BCM connectors...