vechicle speed sensor
- Thread starter 67efivert
- Start date
67efivert said:ok guys im converting my convertable to mass air do i really need a vss hooked up for it to run right id think it wouldnt affect much if any with the straight drive thanks
Vehicle Speed Sensor (VSS) is an electronic sender mounted on the speedo pickup gear on the trans. It works the cruse control for both 5 speed and auto trans cars. On auto trans cars, it tells the computer to speed up the idle slightly as you slow down to a stop to keep the engine from stalling. Check to see if the electrical connector is plugged into it. Cost is under $30 and it is easy to replace.
ok guys this is in my 67 convert i built the harness myself runs fine havent drove it yet though no cruise or anything like that t5 trans will it affect the running any at all im just curious finding a cable to work with my autometer speedo and a vss might be a problem right now the stock cable works perfectally wiring it up isnt a prob just need to know if for some dumb reason if it might affect closed loop or timing curve thanks
Michael Yount
Mustang Master
If the VSS on the T-5 is connected to the pigtail/electrical connection that hangs out of the driver's side, front of the tranny, mine has been disconnected from the computer for the whole 8 years that the engine/tranny have been in the car with no apparent side effects.
I would like to understand more about it however. JRichker -- is that electrical plug hanging out of the front of the tranny connected to an internal vss device? My tranny was purchased new from Ford Racing about 4 years ago - it's a World Class T-5Z. I have an A9L computer, and I've wondered if there's any benefit to hooking up that plug into the computer inputs. Do you know which pins on the ecu plug the wires are supposed to hook to? Also, how does the vss work? Are there magnets and a pickup internal to the tranny? Lots of questions - do you know what type of signal it generates? My after market cruise unit has pin-selection switches that allow for different types of speed signals - square wave, etc.
I would like to understand more about it however. JRichker -- is that electrical plug hanging out of the front of the tranny connected to an internal vss device? My tranny was purchased new from Ford Racing about 4 years ago - it's a World Class T-5Z. I have an A9L computer, and I've wondered if there's any benefit to hooking up that plug into the computer inputs. Do you know which pins on the ecu plug the wires are supposed to hook to? Also, how does the vss work? Are there magnets and a pickup internal to the tranny? Lots of questions - do you know what type of signal it generates? My after market cruise unit has pin-selection switches that allow for different types of speed signals - square wave, etc.
Michael Yount
Mustang Master
67efivert said - "the vechicle speed sensor is only on the speedo cable on a t5 trans"
Can you be more specific? I don't understand your statment. My tranny has a speedo cable which drives my speedometer. Are you saying the VSS is part of the speedo cable set up? Mine just has a plastic gear on the cable that's driven from the plastic gear on the output shaft. If the electronic plug/wires connected to the front of the tranny aren't from a VSS, do you know what they are from?
Can you be more specific? I don't understand your statment. My tranny has a speedo cable which drives my speedometer. Are you saying the VSS is part of the speedo cable set up? Mine just has a plastic gear on the cable that's driven from the plastic gear on the output shaft. If the electronic plug/wires connected to the front of the tranny aren't from a VSS, do you know what they are from?
Michael Yount
Mustang Master
That helps - thanks. Reverse switch is just a little screw in sensor - I used that for my back up light activation. What I'm referring to has an electrical connector much like the ones that plug into the tps sensor or the ACT sensor; it must be a neutral safety switch connection - I'll leave it alone.
Ranchero5.0
The Voice of Reason
67 the vss also speeds up the idle on a 5 speed car as a dashpot device to keep the engine from stalling after an engine brake decel. Without it you may have some surgies when you push the clutch pedal in after decellerating. If the car is prone to surging it may help the puter work out the problems a little, but don't expect the world from it alone. On the MAF conversions I hooked it up on 5 speed cars, but left it off of a AOD car and didn't see any issues.
Michael, the Nuetral safety is on the front of the top plate on the T5.
Michael, the Nuetral safety is on the front of the top plate on the T5.
Michael Yount
Mustang Master
What exactly is it that is on the top plate? Mine has an electrical connector (just like the tps or ACT sensor) that connects to two wires. The two wires run into the top of the tranny. The electrical connector hangs down on the driver's side of the tranny very close to the bell housing/clutch cable port.
67 - no drivability/surging issues realated to lack of a vss.
67 - no drivability/surging issues realated to lack of a vss.
86T-Top
Founding Member
Michael,
The wires that you are talking about, coming from the top plate of the t-5 trans and hangs down the driver side near the bellhousing is for the neutral saftey switch. The VSS is inline on the speedo cable, if you have one, you would have your speedo gear, than the vss, than the speedo cable witch would then go up to the speedometer. The VSS has two wires that plug into the EEC, they plug into pins 3 and 6 in the EEC. The VSS has two purposes, one for cruise control, the other to raise or control the idle when coming to a stop. Just as Jamie said it acts like a dashpot on a Carb. I have heard of plenty of people not running one when they convert their 60's mustang to EFI and not have any surging.
Mario
The wires that you are talking about, coming from the top plate of the t-5 trans and hangs down the driver side near the bellhousing is for the neutral saftey switch. The VSS is inline on the speedo cable, if you have one, you would have your speedo gear, than the vss, than the speedo cable witch would then go up to the speedometer. The VSS has two wires that plug into the EEC, they plug into pins 3 and 6 in the EEC. The VSS has two purposes, one for cruise control, the other to raise or control the idle when coming to a stop. Just as Jamie said it acts like a dashpot on a Carb. I have heard of plenty of people not running one when they convert their 60's mustang to EFI and not have any surging.
Mario
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