Vehicle speed sensor wire?

[techspy]

Anyone know where I can tap into the vehicle speed sensor? I need to connect the new Nav system to it. Does anyone know which pin on the ECM is this wire? Or any other location to connect to it?

Thanks, John
94 S4
http://hometown.aol.com/oneshotcop/myhomepage/profile.html

[JK1]

John,

Not sure where it is at the ecm but you can always access it under the binnacle at the speedo.

Jim

[cnh1990]

I know someone who has the answer. I emailed you his address.

Calvin

[mikelr]

VSS
ECM plug J3- pin c2 (Yellow/Slate) and J3- pin c8 (Purple/Yellow).

Good Luck,
Mike Reed

[techspy]

Thanks Calvin, I just sent him an email.

Jim, being that the speedo is mechanical, would there also be an electronic signal there?

Mike, I found that in my manual, but didn't try to locate them on the ECM because I wouldn't know which one to use. From my past experience, the speed sensor wire should be only one wire and not two.

John
94 S4
http://hometown.aol.com/oneshotcop/myhomepage/profile.html

[JK1]

John,

Sorry, you are correct. Your S4 has a mechanical speedo, my S4s is electronic.

You can still access the wheel speed sensor harness under the front bonnet on the bulkhead. The location of which depends on whether you have an early wiring harness or "revised wiring harness" car which was changed during the production year on the S4.

Jim

[techspy]

Thanks for all the help guys. I connected to the J3- pin c8 location on the ecm. There wasn't a wire or pin in it, so I put one in and connected to the Nav VSS wire. Everything seems to be working correctly.

Thanks again
John
94 S4
http://hometown.aol.com/oneshotcop/myhomepage/profile.html

[JK1]

Very cool, so now do you know where you are going?

[Dr.Hess]

Does my '89-Non-SE have a VSS somewhere as well? That would make putting in an electronic speedo easier and about $30 cheaper, not to mention more reliable.

Dr.Hess

[bojangles]

does that mean you have a source for speedos?
i am searching for a metric one for my S4S

[Dr.Hess]

Oh yeah, I have a source for speedos. Electronic. I'm sure they will do MPH or KPH and may do both in the same unit. They also give you a 0-60 time. www.dakotadigital.com/
Takes a 3-3/8" hole. The hole in our dashes is just a tad over 3-1/8", so it will take a little fileing to get it in, but not much. Only feeds are +/-12v and a pulse for speed. Any pulse, doesn't matter. You set the calibration by pushing a button when you go past a mile marker, then push it again when you get to the next mile marker and that's it, your calibrated. About $250 delivered if you need the pulse generator, $30 less if you can come up with your own pulse.

Dr.Hess

[bojangles]

they are cool, id prefer an analog one...

[Dr.Hess]

Well, I just ordered the Dakota Digital guage, pulse generator and "the adapter nut." Damn odometer went out again and I just don't feel like spending $150 to fix something that is a POS to start with. I suppose the VDO guages are better than the Smiths, and I guess they were trying to improve their QC, but they just didn't get it.

Total delivered was $236.90.

Dr.Hess

[Mark91SE]

Hehe... boy am I late on this one! Hi Jim, glad that worked for you. Calvin thanks for sending him my way.

The ECU 'does' output the VSS (Vehicle Speed Sensor) signal on the
red connector at J2-B8. It outputs 8 pulses per tire revolution.

[pic] www.voicecrystal.com/Esprit/Gauges/ECU_Speedo_Output.jpg [/pic]

I found a connector from my electronics parts bins. This one goes into a larger type "D" connector.

[pic] www.voicecrystal.com/Esprit/Gauges/ECU_Connector_Pin.jpg
[/pic]

I tested the pulses using a multimeter with a beep signal indicator, with one end tied to battery negative and the other to the VSS output. It is an inverted signal, meaning when it is low (grounded) the magnet (or sensor wheel notch) is over the sensor, thus the meter beeps. Then I rotated the tire and counted the beeps.

Mark91SE

[Dr.Hess]

I found the VSS on the ECM in my manual, but I decided to go with a mechanical switch on the speedo cable instead. Simplifies the wiring. If the cable ever goes on me, I'll hook it up to the ECM then. I physically installed my new speedo last night. About an hour to Dremel/Air Die out the hole about 1/8". I'll hook up the electrical stuff tonight. Most of the electrical connections I can pull from the clock plug, which didn't work anyway.

Dr.Hess

[Squelch]

All of the Delco injected Esprits have a VSS. it is in the right rear wheel hub. The Delco ECM wants to get this signal.

The ECM aslo has the output as mentioned earlier, however, the actual output pulses from the ECM are different with different versions of the program code, specifically when Lotus changed to the electronic speedo.

Keep this in mind if using the signal from the ECM and changing the mem-cal.

[JK1]

Squelch said:

All of the Delco injected Esprits have a VSS. it is in the right rear wheel hub. The Delco ECM wants to get this signal. The ECM aslo has the output as mentioned earlier, however, the actual output pulses from the ECM are different with different versions of the program code, specifically when Lotus changed to the electronic speedo. Keep this in mind if using the signal from the ECM and changing the mem-cal.

John,

How can you tell what the actual pulse/mile output is from the ECM to the speedo? As I understand it you can count the teeth on the hub to determine how many pulses/wheel revolution and then convert that to pulses/mile. Is this correct. I realize this would be the signal going into the ECM but what about coming out?

Any help is appreciated.

Thanks,
Jim