Exhaust brake

[CoyleJR]

Does anyone know if it is possible to retro fit my 2006 LBZ with with variable-geometry turbocharger exhaust braking? Below is a GM press release from Aug 2005 posted here on the DP that describes the new improved 2006, LBZ, Duramax 6600. It gives the impression that all of the 2006 LBZ engines had the capability for turbo exhaust braking. Could someone like John Kennedy modify the engine controller program and install an activation switch in the cab of the older model trucks to gain turbo exhaust braking? (Hint hint Kennedy Diesel)

PRESS RELEASE
("Another new feature of the Duramax 6600's turbo system is the capability of the variable-geometry turbocharger to provide exhaust braking. This function is available on some medium-duty truck models and can replace add-on exhaust brake hardware. With the new system, braking is controlled by a signal from the engine controller and can be activated by the driver.")

[Kennedy]

Yes I have done this with decent success. I prefer to do this as a switchable option so that the user can select it on or off. Typically I just do 2 versions of the same tune on a DSP2 switch with one having the brake function. There are those who claim that turbo brake programming only works in TH mode, but that is incorrect. It is not selective. The vanes need to be swung closed tight in coast or 0 fuel rate and at moderate RPM. The Tow/Haul mode does make it much more effective as maintains TCC lockup at lower speeds and increases RPM by using a lower gear at any given ground speed.

That said there is not a huge drawback to having a single tune with Turbo Braking, BUT you may lose some fuel economy due to decreased coasting when driving relatively normal.

[richp]

Hi John,

Could you provide a little more detail about what this would involve, as to both cost and complexity of the conversion?

Thanks.

[Kennedy]

This is available as part of my Kennedy Custom ECM Programming either done up front when purchased or after the fact as an update.

[handirifle]

This is available as part of my Kennedy Custom ECM Programming either done up front when purchased or after the fact as an update.

First post after doing a net search on this topic, thanks ahead for any assistance you can offer.

I know this is an old thread, but I would like to try and figure out this issue on my truck.

I have a 2006 GMC 2500HD, 8th digit VIN code 2, (LBZ engine with MD tune, truck build Sept 2005), 6spd Allison tranny. As per the instructions found on another GM diesel web forum, I installed a switch that pins directly to the ECM plug, and thus the ECM. The switch runs one circuit to ground to activate the turbo brake (TB) and the other to illuminate the "telltale" light.

So far all attempts, including using a V2 to flash another KNOWN working LBZ tune into my truck, and still no avail.

Is there something mechanical that could prevent this? I am getting no check engine codes, and have tested numerous times meeting the necessary criteria, speed above 15mph, TC locked, engine at normal operating temps (200), switch on (ECM pin grounded), RPM above 1100, coasting or throttle at zero %, and TH mode on, just in case. No telltale light. The turbine does sound a little louder, but am not sure that is the braking, or just because TH mode keeps RPM's higher.

Anything else you can think of to look for?