95 4l60E speedometer calibration...

marty79

marty79

Well-Known Member
Joined
Dec 2, 2015
Location
Newton, NC
I see there the VSSB calibration on the little module behind the glove box but I also see you can buy different speedo gear that goes on the T-Case to correct the speed. It's time to correct my speedo with my new gears and tires. (reading 90 at 68 lol). I went from 3:42 to 4:10, currently on 255/70 16s. Any help in right direction would be great.
 
a_kelley said:
New speedometer gear or get a calibration box (modifies the output of the speed sensor electrically)
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That doesn't work on 91-95 otherwise I would have
 
1001101.. is my calculation setup... according to post, 1 means "jumped" and 0 means "open"??? I don't understand what this means.
Then it says 7 numbers on left have to be opposite of ones on right ...right side being where you input the "jumpers"...so if a slot on the right is "jumped" than that corresponding side is open?? Thank you
 
marty79 said:
Ive read through those guys but seems out of my league..or I'm overthinking it?? Was wondering if anyone has done it and could simplify it lol. I'm not tech savvy with reading comprehension. Thanks (might be lost cause)
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Look at the page I linked, which has the jumper settings and their corresponding input ratio, and also the gear ratios for the available RPO codes. It also has a speedo calculator that calculates the input ratio.

You put your tire size in the calculator fields, and the gear ratio, and it calculates the input ratio. Then you find the closest input ration value in the list of jumper settings, and that's your jumper setting. Then you grab your trusty soldering iron (or find someone to do it for you) and move the jumpers inside the VSSB to the proper (new) locations.
 
marty79 said:
1001101.. is my calculation setup... according to post, 1 means "jumped" and 0 means "open"??? I don't understand what this means.
Then it says 7 numbers on left have to be opposite of ones on right ...right side being where you input the "jumpers"...so if a slot on the right is "jumped" than that corresponding side is open?? Thank you
Click to expand...

At the top of the table, it says
1 = JUMPER CONNECTED OR SWITCH ON
0 = JUMPER NOT CONNECTED OR SWITCH OFF

Look at the pictures at the top, the jumpers connect from one row of holes to the other row. If you don't feel comfortable moving the jumpers because you aren't experienced with a soldering iron, ask for help.

I'm honestly not sure what's going on with the "inverse" jumpers, and why they are different than the other set.
 
Fabrik8 said:
Look at the page I linked, which has the jumper settings and their corresponding input ratio, and also the gear ratios for the available RPO codes. It also has a speedo calculator that calculates the input ratio.

You put your tire size in the calculator fields, and the gear ratio, and it calculates the input ratio. Then you find the closest input ration value in the list of jumper settings, and that's your jumper setting. Then you grab your trusty soldering iron (or find someone to do it for you) and move the jumpers inside the VSSB to the proper (new) locations.
Click to expand...
I can't solder if my life depended on it lol, last time I tried it was as epic as my control arms used to be :lol:. So I'll have to take it to someone once I can guide them of what to do...plus knowing my luck I'd fry the board with static electricity lol.
 
Fabrik8 said:
If you don't feel comfortable moving the jumpers because you aren't experienced with a soldering iron, ask for help
Click to expand...
Yeah I'm definitely going to have to go somewhere. Just can't look like a total idiot and gotta tell em what to do.
 
marty79 said:
Then it says 7 numbers on left have to be opposite of ones on right ...right side being where you input the "jumpers"...so if a slot on the right is "jumped" than that corresponding side is open?? Thank you
Click to expand...

Yes, you're right. The positions are inverted, so if #6 on the right is open, #6 on the left needs to have a jumper placed there.
 
VSSB.jpg

So in slot on the right, my numbers are 1001101. So I put a "jumper" in slot 1, not 2 or 3 put one in 4 and 5 not 6 and one in 7?? Is that right
 
Fabrik8 said:
Do you need the VSSB (is it from your daily driver) or could you do without it for a little while?
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It's our only vehicle currently but can it be driven without it..just no speedo working??
 
Fabrik8 said:
Do you need the VSSB (is it from your daily driver) or could you do without it for a little while?
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My neighbor is giving me his car all next week to use if needed...that could be my time to get this done
 
Well thank you for all your help @Fabrik8 very much, any idea of what I can expect to pay for this to be done at electronic shop?
 
I may happen to be a former electronics technician (and circuit board designer), but I am not able to help you out for about a week. Will be gone for a few days for a family emergency. :(

You're also not exactly next door (about an hour away), so would need to ship it.

I can, however, install DIP switches if you want so you can change jumper settings anytime you need (including if the calculation was wrong, or you change tires, or whatever).

I've never modified one of these before, but it looks reaaaaally easy. I've modified hundreds of ECUs back in the day (side business for the Honda guys), so this is not any different.
 
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Well got this module done and sweet now I'm 3mph off woohoo. Funny though cause my RPMs read different and transmission shifts much better and smoothly.. pretty cool.
 
marty79 said:
Well got this module done and sweet now I'm 3mph off woohoo. Funny though cause my RPMs read different and transmission shifts much better and smoothly.. pretty cool.
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That seems to be the big reason to use dip switches instead of jumpers, because you can tweak to your hearts content and try the next closest setting if the mph is still a little off, etc.
 
Fabrik8 said:
That seems to be the big reason to use dip switches instead of jumpers, because you can tweak to your hearts content and try the next closest setting if the mph is still a little off, etc.
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I can live with 3 lol. It was 18 off before LMBO
 
If you need something soldered then just bring it over. I got certifications n shit.
 
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