Speed pulse indicator??

[bhw33191]

So i installed a "new" radio today. Its a 2006 Pioneer Avic N3. Its one of those fancy ones with the flip out screen and gps, etc. But anyway, theres a wire called "speed pulse indicator" it basically does just that and helps the GPS keep track of where the car is. Now, being an 83 caprice, is there even a place to hook this up in older cars? I couldn't seem to find an answer in the directions. I got this radio for free and already had a GPS before this so its no loss if i can't get it to work, but it'd be nice if i could of course.

[j cAT]

Originally Posted by bhw33191

So i installed a "new" radio today. Its a 2006 Pioneer Avic N3. Its one of those fancy ones with the flip out screen and gps, etc. But anyway, theres a wire called "speed pulse indicator" it basically does just that and helps the GPS keep track of where the car is. Now, being an 83 caprice, is there even a place to hook this up in older cars? I couldn't seem to find an answer in the directions. I got this radio for free and already had a GPS before this so its no loss if i can't get it to work, but it'd be nice if i could of course.

you have a tranny cable to the odometer ,,,,no pulsing sensor for speed ....

[bhw33191]

Originally Posted by j cAT

you have a tranny cable to the odometer ,,,,no pulsing sensor for speed ....

Yeah just did another search and found out that cars with ABS have a speed pulse sensor. And obviously mine has no ABS so i guess i'm outa luck

[silicon212]

Originally Posted by bhw33191

Yeah just did another search and found out that cars with ABS have a speed pulse sensor. And obviously mine has no ABS so i guess i'm outa luck

If it has true GPS, there's no need for the speed pulse sensor. Any GPS unit worth "its salt" will tell you how fast you're going regardless, it's a part of GPS.

Heck, MS Streets and Trips with a cheapo GPS mouse tells me how fast I am going when I have the Toughbook in the car. It's amazingly accurate.

[bhw33191]

Originally Posted by silicon212

If it has true GPS, there's no need for the speed pulse sensor. Any GPS unit worth "its salt" will tell you how fast you're going regardless, it's a part of GPS.

Heck, MS Streets and Trips with a cheapo GPS mouse tells me how fast I am going when I have the Toughbook in the car. It's amazingly accurate.

Yeah the unit actually has a set of "virtual" gauges which are really nice. I tested it out yesterday and it showed my speed and was quite accurate also. So its kind of confusing why the GPS has trouble calibrating itself..especially since it cost $1200 back in 06

[caffeineaholic]

When I read "speed pulse indicator" it makes me think of the Vehicle Speed Sensor (VSS), which I believe is for the cruise control module rather than the ECM. However I wouldn't necessarily recommend hooking it up to that if your car has one...

[silicon212]

The VSS is indeed for the ECM.

[Blue Bowtie]

There is a reasonable chance that the 1984 has a VSS. If there is no vacuum line to the distributor and there is an ESC unit mounted to the firewall, there is very likely a VSS behind the speedometer. Even though the speedo is cable driven there might be an optical VSS. If so, there should also be a yellow plastic VSS buffer box mounted under the dash near the ECM (in the RH kick panel). This buffer conditions the VSS signal (creating a clean square wave output) and splits it for the ECM and cruise control servo on some models. Canadian models didn't get this until later years. Even some domestic models may have had a split speedo cable with one half routed to the cruise servo. The ECM would have used the VSS input for TCC control and ignition retard on decel.

If this is the case you may be able to split the VSS signal after the buffer and feed it to the head unit. It is possible that the VSS is used for the GPS as well as speed controlled volume functions like the factory did.

[caffeineaholic]

Originally Posted by Blue Bowtie

There is a reasonable chance that the 1984 has a VSS. If there is no vacuum line to the distributor and there is an ESC unit mounted to the firewall, there is very likely a VSS behind the speedometer. Even though the speedo is cable driven there might be an optical VSS. If so, there should also be a yellow plastic VSS buffer box mounted under the dash near the ECM (in the RH kick panel). This buffer conditions the VSS signal (creating a clean square wave output) and splits it for the ECM and cruise control servo on some models. Canadian models didn't get this until later years. Even some domestic models may have had a split speedo cable with one half routed to the cruise servo. The ECM would have used the VSS input for TCC control and ignition retard on decel.

If this is the case you may be able to split the VSS signal after the buffer and feed it to the head unit. It is possible that the VSS is used for the GPS as well as speed controlled volume functions like the factory did.

The only thing I'd be a little worried about is if it will adversely affect the ECM or buffer box. I'm not an expert at electronics but I'd be worried that the ECM or buffer box could be damaged. Perhaps the signal could also be affected giving false readings to the buffer box or ECM? Just my