VSS 4k to 2k pulse? Newbie question
11-28-2006, 01:23 PM
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Engine: 5.7 vortec crate w/TPI
Transmission: 2004r
Axle/Gears: 3.42
VSS 4k to 2k pulse? Newbie question
Alright, I searched for it, but didn't see anything conclusive, and just wanted to make sure.
My transmission (2004r) comes with a 2k pulse VSS with a cable drive for the speedometer. However, since I'm using SD, the computer is assuming that I have a 4k pulse VSS. Are there flags/constants that I can set to tell the computer to use the 2k signal, and if so, what are they?
I'd prefer not to have to buy a brand new VSS if possible.
My transmission (2004r) comes with a 2k pulse VSS with a cable drive for the speedometer. However, since I'm using SD, the computer is assuming that I have a 4k pulse VSS. Are there flags/constants that I can set to tell the computer to use the 2k signal, and if so, what are they?
I'd prefer not to have to buy a brand new VSS if possible.
11-28-2006, 04:14 PM
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Car: 80 GMC K35
Engine: TPI 355
Transmission: NV4500
Axle/Gears: 4.10
Yep, change 0x00000018 from D4 to 94 if you're editing the straight code.
If you are using Tunerpro RT or something, it should mention something about a magnetic speed sensor being installed installed, which you do not, so you need to flag it as not set. You'll then need to run the 2000 pulse per mile signal wire to pin C6 of the 7730.
If you are using Tunerpro RT or something, it should mention something about a magnetic speed sensor being installed installed, which you do not, so you need to flag it as not set. You'll then need to run the 2000 pulse per mile signal wire to pin C6 of the 7730.
Last edited by 80Sierra; 11-28-2006 at 04:21 PM.
01-02-2007, 01:17 PM
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Engine: 5.7 vortec crate w/TPI
Transmission: 2004r
Axle/Gears: 3.42
So I just had a thought: If I do this, will all the other calculations done by the ECM work properly?
01-03-2007, 11:05 AM
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Car: 1988 Monte Carlo SS
Engine: 5.7L TPI
Transmission: T5
Axle/Gears: 3.73
Yes, just flip the bit and feed the 2000 ppm signal into the optical VSS input of the 730 ECM. The ECM will take care of the rest for you.
01-03-2007, 11:26 AM
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Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)
Engine: 406 Hyd Roller 236/242
Transmission: 700R4 HomeBrew, 2.4K stall
Axle/Gears: 3:73 Posi, 7.5 Soon to break
He's been known to frequent that board too! 
Good to see another SS that thinks its a thirdgen TPI.
Good to see another SS that thinks its a thirdgen TPI.
01-03-2007, 11:36 AM
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Engine: 5.7 vortec crate w/TPI
Transmission: 2004r
Axle/Gears: 3.42
Yup, my car's going through some "Thirdgen-envy" right now
And I don't know if you remember, but thanks for the wiring diagrams awhile back. They've been a huge help so far.
And I don't know if you remember, but thanks for the wiring diagrams awhile back. They've been a huge help so far.
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05-07-2007, 08:36 AM
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Engine: 5.7 vortec crate w/TPI
Transmission: 2004r
Axle/Gears: 3.42
Re: VSS 4k to 2k pulse? Newbie question
Bump, since I'm actually trying to wire this up now.
Sorry if this is a really basic question, but can anyone explain how to wire up the 2000 pulse VSS buffer box to the 730 ECM? Is it just one wire going to pin C6 of the ECM?
To make sure we're on the same page, it looks like it would connect to the cruise control wiring, which is expecting a 2000 pulse input (Pin C6?), and flipping the flag previously mentioned would "tell" the RCM to get its VSS input from there?
Any help would be much appreciated! I've almost got this sucker wired up!
Sorry if this is a really basic question, but can anyone explain how to wire up the 2000 pulse VSS buffer box to the 730 ECM? Is it just one wire going to pin C6 of the ECM?
To make sure we're on the same page, it looks like it would connect to the cruise control wiring, which is expecting a 2000 pulse input (Pin C6?), and flipping the flag previously mentioned would "tell" the RCM to get its VSS input from there?
Any help would be much appreciated! I've almost got this sucker wired up!
05-07-2007, 10:01 PM
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Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)
Engine: 406 Hyd Roller 236/242
Transmission: 700R4 HomeBrew, 2.4K stall
Axle/Gears: 3:73 Posi, 7.5 Soon to break
Re: VSS 4k to 2k pulse? Newbie question
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