Tunes won't load

[Grinchanderson]

I have an 03 lb7 and when we load the tunes they won't work with the dsp5 switch. Although we did a
test and the switch does work its just tunes wont work. If we load just one tune at a time it works. Been
struggling for a few days please help.

[Dmaxink]

Have you used the scan tool to Confirm when you switch it that the voltages change to match the desired voltages in your tune?

[Grinchanderson]

Yes and it's showing no values whether the truck is on or off. It's not logging the truck for some reason. If you load a
single tune it works great. Soon as you load the dsp5 it doesn't work. It feels like it has 50 horse and no boost.

[Dmaxink]

So when you move the switch from position 1-2-3-4-5..what voltage values are you seeing?

[Grinchanderson]

No values. They stay blank. We put a lope tune on number 5 and it works but when
You go to race on 1 it's in like a limp mode.

[Dmaxink]

If it is a tune you guys built i wouldnt mind looking over it for you..however, it is another tuners tune i wont as to respect their property...

[Grinchanderson]

We have tried twenty tunes now. Four sets of five and
Still does not work. I don't know what else to check.
The tunes are good on another truck the dsp 5 works on
Number 5 with a lope but it's in a limp kinda mode
On the other four tunes. Any advice appreciated.

[ScarabEpic22]

What are the voltages you have set in the tunes, and do you see the voltage value in the scan tool PID change when you move the switch? If not, recheck your pins.

[GMC-2002-Dmax]

Did you install the switch pins and make sure they were seated all the way ?

[Grinchanderson]

Turns out the problem was the mass air flow sensor. It's fixed and runs good