LB7 Kodiak Exhaust Brake Wiring

Bdsankey

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I am attempting to activate the OEM exhaust brake feature like on a Kodiak with my LB7. From what I gather on the GM Upfitter's information I need J1-72 for the switch (I don't know if I ground this or apply power) and I need pin J2-7 for the relay which I believe is +12V out.


Does anyone have any experience with this request? I've attached a screen grab of the GM Upfitter's page as well.


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2004LB7

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Looks like it to me.

Look at pages D53 and D209. Switch is grounded. And the output powers a solenoid to ground on page D52
 

fl0w3n

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I'm interested in what you come up with... but also confused, how does factory exhaust braking work without a VGT turbo?

Edit: just realized you said exhaust brake and not turbo brake, so I'm assuming you're adding an aftermarket brake but looking for it to be controlled through the ECM?
 

Bdsankey

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I'm interested in what you come up with... but also confused, how does factory exhaust braking work without a VGT turbo?

Edit: just realized you said exhaust brake and not turbo brake, so I'm assuming you're adding an aftermarket brake but looking for it to be controlled through the ECM?
The LB7 Kodiak trucks had an option for an actual exhaust brake which was armed with a switch and then provides an output signal to be ran to the exhaust brake’s activation solenoid.

That said, I called my tuner and talked over what I wanted to do. The issue he believes that will arise is my truck is a 2002, the Kodiak was LB7 powered in 2003 meaning I’d have to swap to a different OS. The issue he believes there is that I’ll not only lose the ability to be DSP5 but also believes it’ll cause issues with HVAC control so that’s going to be a no-go. I’ll run it off a switch and if I want to get crazy I’ll write some coding for a RaspberryPI board to activate it as set rpm/speed/tps etc or just be normal and toggle it on/off.
 

fl0w3n

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That’s pretty cool, didn’t know that about the Kodiak.

Were you/are you going to use a factory brake or use an aftermarket one?

bummer about the OS, I figured you were intending this for your black 02 build
 

Bdsankey

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That’s pretty cool, didn’t know that about the Kodiak.

Were you/are you going to use a factory brake or use an aftermarket one?

bummer about the OS, I figured you were intending this for your black 02 build
I was planning on running a PacBrake 4”. I don’t know who the OEM brake was for the LB7 Kodiak trucks is but the ecm output triggers any common brake activation solenoid.
 

Chevy1925

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You will for sure loose a/c compressor control and DSP if you run an 03-04 OS. Tried that many years ago.

If he can segment out the exhaust brake control area and patch it into the 02 OS, it should work, provided nothing is on those pins currently.
 

Bdsankey

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You will for sure loose a/c compressor control and DSP if you run an 03-04 OS. Tried that many years ago.

If he can segment out the exhaust brake control area and patch it into the 02 OS, it should work, provided nothing is on those pins currently.
10-4, I don’t know much about patching in the exhaust brake. The pins on a pickup are unused according to Mitchell1 and AllData.

Worst case scenario I end up using the pac-brake controller and spending more money.


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