DSP5 Voltages

[ruralgas]

Hi Folks:
Just installed my DSP5 switch and it works fine except on one setting. On my setting #1, I only can get 58mv for a reading??
I have my switch set up as follows:
Switch setting #1 is my stock tune and the voltage is 58mv. (???)
Switch setting #2 is an econ tune and the voltage is 3.53 volts.
Switch setting #3 is a 60hp tune and the voltage is 2.36 volts.
Switch setting #4 is a 70hp tune with turbo brake and the voltage is 1.45 volts.
Switch setting #5 is an "anti-theft" tune and the voltage is 0.49 volts.
All the settings work as they should except for #1??
The truck runs in settings 2, 3 and 4. It shuts off and or won't start in setting 5 as it should. But it also shuts off and or won't start in setting 1 because of the low voltage. I believe I should be seeing about 4 to 4.5 volts?
These are readings off my DVM and the my computer with EFI.
I've checked my resistors, switch and wiring and all is good.
Could there be a problem with my DSP5 tune?
I am puzzled and getting frustrated with this DSP stuff.
If someone could please help me out that would be very much appreciated.
I'll give it another try as I think I am close.
Please accept my thanks in advance for your help.
Garry

[GMPX]

I would expect somewhere over 4V for position #1.
Speak to the person you got the switch from, if the switch is reading 58mV on a multimeter in position #1 it's nothing to do with the ECM or the tune.

[ruralgas]

Hi GMPX:
I put the switch together myself. I used the resistor values that are in the EFI tutorial.
When I checked my DSP wires from the ECM, without the switch, I got 5.05 volts. When I connected the 27k resistor that's when I get 58mv. All the other resistors gave me the correct voltages.
I tried some other resistors from my "old" stock and found that a 12k resistor gave me 4.45 volts.
Put that in and my DSP voltages are good and the switch works like it should.
Checked it with my computer and it changes tunes like it's suppose to.
Just a question on that 27k resistor. Isn't that to "big" of resistor?
Is that maybe just a miss print in the tutorial? It sure throws a "curve ball" at a person when you go to make a switch.
I just wanted to share my experience with you folks.
Thanks.
Garry

[GMPX]

It's not a mis-print, the higher the resistance the higher measured the voltage.

[Ira]

Just remove the 27K resistor and bin it, it's not needed. it sounds like it's closer to 27 ohms.

Ira