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Discussion Starter · #1 · (Edited)
UPDATED: Speed wire for GPS

Anyone know where this wire can be found in a 2002 durango? I have a head unit w/GPS that needs to be hooked up to the speed wire. Any help is greatly appreciated!
Thanks,
dogthenine
 

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What does it need the speedo wire for? Just about any GPS device can measure speed from the info its sent from the satellite.
 

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Yeah, why do you need the speed sensor input for a GPS head unit? If it can't tell actual speed from the GPS satellites, then you may want to look for a better GPS head unit.
 

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The speed sense wire works with gyroscopes inside the unit to allow the GPS to continue providing real-time data whenever signals are lost, such as passing through tunnels and under overpasses. Your best bet is at pin #27 on the #2 connector of the PCM. That way, if you change your tire size the unit will still read properly as long as you get the ABS controller programmed with the proper size. If you connect to the sense wire from the sensor on the axle you'd have to reprogram the GPS as well after changing tire size.
 

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The speed sense wire works with gyroscopes inside the unit to allow the GPS to continue providing real-time data whenever signals are lost, such as passing through tunnels and under overpasses. Your best bet is at pin #27 on the #2 connector of the PCM. That way, if you change your tire size the unit will still read properly as long as you get the ABS controller programmed with the proper size. If you connect to the sense wire from the sensor on the axle you'd have to reprogram the GPS as well after changing tire size.
Exactly.. It's called "Dead Reckoning". Most factory installed GPS units have it, but it is not a feature that gets a lot of press. It comes in handy when you're in tunnel "systems" such as those in Boston and Baltimore, where the tunnels split into exits. Standard GPS is useless in this situation because it stops working as soon as you enter the tunnel. Even skyscraper-lined streets can block out the satellite signal when you're driving through big cities. I had problems with mine in NYC all the time.
 

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That's interesting. Never heard of it. Of course living in the midwest, it's not really a problem. I have my GPS antenna mounted inside my dash and it works fine. The Magellen unit in my car is installed in the sunglass holder and picks up a good signal through the car roof, so never really though it would be much of a problem.
 

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Discussion Starter · #9 ·
The speed sense wire works with gyroscopes inside the unit to allow the GPS to continue providing real-time data whenever signals are lost, such as passing through tunnels and under overpasses. Your best bet is at pin #27 on the #2 connector of the PCM. That way, if you change your tire size the unit will still read properly as long as you get the ABS controller programmed with the proper size. If you connect to the sense wire from the sensor on the axle you'd have to reprogram the GPS as well after changing tire size.
Do you happen to know what color the wire is?
 

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Discussion Starter · #12 ·
SPEED SENSE white/orange or blue conn. 2, pin 27 @ PCM *6

UPDATE: This wire does not work, does not send speed info to unit. Wouldn't this wire just be relaying the number of times the drive shaft is turning, so the PCM can convert it to MPH? Wouldn't I need a wire coming out of the PCM that has the converted info? Is there a wire that feeds the speedo in the dash?
 

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Discussion Starter · #13 ·
Well, I finally found out that that wire is the right one. The pin in the radio harness was damaged, fix it and everything works.
 
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