Tired of Edge Problem, any help?
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Tired of Edge Problem, any help?
I have had my edge evo cs for about a month and a half now. I love the performance of the towing tune, and the gauges are sweet. However, I am tired of not having my speedometer calibrated. And yes I know that the edge unit will read a little off of the ford speedometer, both are off. when going 75 via gps speed, my edge reads 68 mph. It is about as far off as it was before I got the edge. I have programmed and reprogrammed tons of times, changing the tire size, but it is always off. I called edge, and they walked me through the steps, still off. Then they had me plug my unit in to Fusion, and they took files off of it to look at, and then later called and took even more off. Their verdict was that the engineers told them the Revolutions per mile were changing with the programming of 35's, and nothing was wrong. There is definately something wrong, anyone know what the problem could be? Any help at all will be appreciated.
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Is the gear ratio correct?
What is the tire ratio? If the tire is really 35" (diameter), I would try 3% squish (35 x .97 = 33.95 diameter/height) and then adjust from there.
What is the tire ratio? If the tire is really 35" (diameter), I would try 3% squish (35 x .97 = 33.95 diameter/height) and then adjust from there.
Last edited by shotgunz; Dec 7, 2010 at 06:15 PM.
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From: College Station
I have a gps, and no matter what I do to the tire size numbers, the speed readout it the same amount off
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I have been using the custom option way. However, when I first got it I think I used the on screen menu way
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From: In the fast lane from LA to Tokyo...
You might want to check your tire size in the on screen menu way.....
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From: Among javelinas and scorpions in Zoniestan
What size tires and gears do you have in your truck? Please let me know these values and I MAY be able to help. (My speed reading and odometer readings are correct, but I can't simply use the Tire Size in the "Options" menu. I have to adjust it in the "Custom Options" menu.)
- Jack
- Jack
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From: College Station
What size tires and gears do you have in your truck? Please let me know these values and I MAY be able to help. (My speed reading and odometer readings are correct, but I can't simply use the Tire Size in the "Options" menu. I have to adjust it in the "Custom Options" menu.)
- Jack
- Jack
EDIT: I have 3:73 gears
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From: NC
Unloaded (no squish) diameter/height: 35.098"
3% squish diameter/height: 34.05"
4% squish diameter/height: 33.69"
5% squish diameter/height: 33.34"
Unloaded (no squish) circumference: 2800.7mm
3% squish circumference: 2717
4% squish circumference: 2689
5% squish circumference: 2661
Again, I would start with 3% squish and adjust using a GPS or known distance (10 or more miles; see the formula below).
Obviously it's critical that the GR be correct in the custom options.
3% squish diameter/height: 34.05"
4% squish diameter/height: 33.69"
5% squish diameter/height: 33.34"
Unloaded (no squish) circumference: 2800.7mm
3% squish circumference: 2717
4% squish circumference: 2689
5% squish circumference: 2661
Again, I would start with 3% squish and adjust using a GPS or known distance (10 or more miles; see the formula below).
Obviously it's critical that the GR be correct in the custom options.
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From: Among javelinas and scorpions in Zoniestan
OK, everyone is here ahead of me (shows what happens if you decide you need to sleep).
In your original post, you said the Edge reads 68 when the GPS shows 75. We'll assume the GPS is correct (but it WILL have some "lag", and the Edge won't). Speed readings are best made on a straight, level stretch of highway with the cruise control set and over about a 10 second interval.
Anyway, your PCM thinks your tires are smaller than they really are if your Edge (the PCM) reads low and your Gear Ratio (GR) is set properly. So, please verify that you really do have a 3.73 GR set in the "Custom Options" menu (as shotgunz advised).
Now, I don't have any faith at all in the Tire Size (TS) value that is set in the "Options" menu, so even though my tire specs are entered there, I always make sure an "adjusted" diameter is set in the "Custom Options" menu. Here, on the CS/CTS platform, I've found it's easiest to use inches, and you can enter a value that is correct to the nearest tenth of an inch.
When I check Nitto's chart, it tells me 585 revs/mile for your tires and that corresponds to a "loaded" diameter of 34.5". That's what I'd start with. Then if the Edge still reads too slow, increase the value. If too fast, decrease the value. Remember, the PCM must be reprogrammed with this new value, or it will have no effect.
If you need to correct, you can use shotgunz' formula too, substituting speeds for odometer readings, i.e.:
- Jack
In your original post, you said the Edge reads 68 when the GPS shows 75. We'll assume the GPS is correct (but it WILL have some "lag", and the Edge won't). Speed readings are best made on a straight, level stretch of highway with the cruise control set and over about a 10 second interval.
Anyway, your PCM thinks your tires are smaller than they really are if your Edge (the PCM) reads low and your Gear Ratio (GR) is set properly. So, please verify that you really do have a 3.73 GR set in the "Custom Options" menu (as shotgunz advised).
Now, I don't have any faith at all in the Tire Size (TS) value that is set in the "Options" menu, so even though my tire specs are entered there, I always make sure an "adjusted" diameter is set in the "Custom Options" menu. Here, on the CS/CTS platform, I've found it's easiest to use inches, and you can enter a value that is correct to the nearest tenth of an inch.
When I check Nitto's chart, it tells me 585 revs/mile for your tires and that corresponds to a "loaded" diameter of 34.5". That's what I'd start with. Then if the Edge still reads too slow, increase the value. If too fast, decrease the value. Remember, the PCM must be reprogrammed with this new value, or it will have no effect.
If you need to correct, you can use shotgunz' formula too, substituting speeds for odometer readings, i.e.:
(GPS speed/Edge Speed) x Old Tire Diameter = New Tire Diameter
Let us know what happens, please.- Jack
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OK, everyone is here ahead of me (shows what happens if you decide you need to sleep).
In your original post, you said the Edge reads 68 when the GPS shows 75. We'll assume the GPS is correct (but it WILL have some "lag", and the Edge won't). Speed readings are best made on a straight, level stretch of highway with the cruise control set and over about a 10 second interval.
Anyway, your PCM thinks your tires are smaller than they really are if your Edge (the PCM) reads low and your Gear Ratio (GR) is set properly. So, please verify that you really do have a 3.73 GR set in the "Custom Options" menu (as shotgunz advised).
Now, I don't have any faith at all in the Tire Size (TS) value that is set in the "Options" menu, so even though my tire specs are entered there, I always make sure an "adjusted" diameter is set in the "Custom Options" menu. Here, on the CS/CTS platform, I've found it's easiest to use inches, and you can enter a value that is correct to the nearest tenth of an inch.
When I check Nitto's chart, it tells me 585 revs/mile for your tires and that corresponds to a "loaded" diameter of 34.5". That's what I'd start with. Then if the Edge still reads too slow, increase the value. If too fast, decrease the value. Remember, the PCM must be reprogrammed with this new value, or it will have no effect.
If you need to correct, you can use shotgunz' formula too, substituting speeds for odometer readings, i.e.:
- Jack
In your original post, you said the Edge reads 68 when the GPS shows 75. We'll assume the GPS is correct (but it WILL have some "lag", and the Edge won't). Speed readings are best made on a straight, level stretch of highway with the cruise control set and over about a 10 second interval.
Anyway, your PCM thinks your tires are smaller than they really are if your Edge (the PCM) reads low and your Gear Ratio (GR) is set properly. So, please verify that you really do have a 3.73 GR set in the "Custom Options" menu (as shotgunz advised).
Now, I don't have any faith at all in the Tire Size (TS) value that is set in the "Options" menu, so even though my tire specs are entered there, I always make sure an "adjusted" diameter is set in the "Custom Options" menu. Here, on the CS/CTS platform, I've found it's easiest to use inches, and you can enter a value that is correct to the nearest tenth of an inch.
When I check Nitto's chart, it tells me 585 revs/mile for your tires and that corresponds to a "loaded" diameter of 34.5". That's what I'd start with. Then if the Edge still reads too slow, increase the value. If too fast, decrease the value. Remember, the PCM must be reprogrammed with this new value, or it will have no effect.
If you need to correct, you can use shotgunz' formula too, substituting speeds for odometer readings, i.e.:
(GPS speed/Edge Speed) x Old Tire Diameter = New Tire Diameter
Let us know what happens, please.- Jack
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From: Durham,NC
Im having the same problem but the kicker is my tires/gr are stock........my speedometer is reading 75 and the cs is reading 68,with my wife right next to me in her bone stock 08 tahoe she said we were running 70? Any ideas for me? Highjacking not intended,by the way!
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From: College Station
okay, hopefully this will help someone who is good at this stuff. So i went to the read trouble codes function on my edge cs and I have p1602 which i looked up and it means -Immobilizer module-(PCM) communication fault. would this have anything to do with my tire size not changing my speed?
