Help with 5 position mystery switch

[meanpeace]

I just got a 05 LLY Duramax (6.6) with a 5 position switch. I am assuming its efi live. How can I tell? There was no Autocal unit that came with the truck. The dealer is clueless about it as I am. The switch does work, however I dont know what position does what. What would you do in this scenario? Will I eventually need a Autcal? Will getting one work on this? Help a brutha out!

[Move'n Up]

Other then data logging and running it on a dyno for each position on the switch there is no way to tell. DSP5 tunes can not be read out of the ECM. Generally speaking position 1 is stock, or at least close to it, 2 is tow or sometimes economy and 3, 4, and 5 are progressively hotter tunes. 5 being a race tune. The HP & Trq increase is all dependent on what other modifications the truck has and if the transmission is built and to what degree.

[meanpeace]

I greatly thank you for your response and knowledge! Flipping through the positions Yes it seems like #1 (all the way counter clock) is stock position. #4 and #5 Slings me back in the seat and the tires about squeel :-)
Dont recall if its #2 or #3 position that has a unigue double baffle idle (best I can describe, im new to this stuff)
I am happy with what it does. Im just concerned with adjusting etc if the need be in the future. I was advised by a friend to get a cts insight to monitor/adjust the efi. Either way I want to stay ahead of the game. Again thank you for your wisdom and quick response!

[Move'n Up]

Your welcome. You'll probably find that position 3 or 4 are your best daily drive settings.

A good set of gauges or a CTS is advised. Monitoring EGT's is very important if you tow or run the hot tunes. Trans temp is also good to keep an eye on if you tow much.

[meanpeace]

Yes I plan on getting a cts. I definately want to monitor stuff. Im not sure if I will have to do away with dsp however. From what I gather the cts cant change dsp settings unless its switched to serial. But I will need an autocal inorder to do that? And if I get ecm flashed I will lose dsp? Im still trying to weigh out best option and feel like im screwed by not having the original autocal. If I want to add monitoring I might have to consider my exsisting dsp a loss? I do not tow much but I want the option to monitor all possible. If this was your truck what would you do?

[Move'n Up]

Other then monitor there is nothing else that you can do with the CTS. I believe with the Duramax a DSP5 tune has to be built specifically to work with the CTS for tune switching. Your 5 position switch is all you need to switch tunes. As far as modifying your tunes you have a tough road ahead of you. The original tune file and or the actual tuner shop must be located, depending on weather or not it was an AutoCal tune or someone tuned it with a V2. You might get lucky by calling every tuner to see if you get a VIN # match that they tuned but that's a long shot!

If it were me and I was satisfied with the way the truck runs then I would just install an EGT and Trans gauge and possibly boost gauge and be done with it.

[meanpeace]

I can still monitor via the obd2 correct? If so, I am happy with the tuner and would be happy just monitoring what I already have. My primary concern is keeping an eye on injector ballance rates, fuel pressure, and what you mentioned.

[Move'n Up]

Yes you can monitor most items via the OBDII port but you will need a pyrometer tied to a gauge or CTS in order to monitor EGT's. I'm not sure if your year and model can monitor Trans temp. Someone else will hopefully chime in on that item.