5.3 into Jeep VSS Question
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5.3 into Jeep VSS Question In the middle of a '06 5.3 swap into a 92 Jeep Wrangler rockcrawler. I am using a manual transmission and jeep transercases. The only location for a VSS is in the rear output shaft. I would like to use the Jeep VSS but not sure if it will work, have gotten mixed answers.
The Jeep VSS is a three wire unit: signal, ground & 5 volt reference and outputs 8000 ppm.
1. Can I feed the Jeep VSS a 5 volt reference and have the ECM read this signal through pins: C2, 20 & 21?
2. I have heard that scaling back the VSS input down this low (8000ppm) does not work that well as the ECM really likes a higher resolution. Can anyone confirm or deny this?
3. Or any other suggestions on how to make this work. The transfer case has a standard mechanical speedocable output but all the VSS I have found that can bolt up have 4000 ppm or less so I am back to question 2.
Thanks
The Jeep VSS is a three wire unit: signal, ground & 5 volt reference and outputs 8000 ppm.
1. Can I feed the Jeep VSS a 5 volt reference and have the ECM read this signal through pins: C2, 20 & 21?
2. I have heard that scaling back the VSS input down this low (8000ppm) does not work that well as the ECM really likes a higher resolution. Can anyone confirm or deny this?
3. Or any other suggestions on how to make this work. The transfer case has a standard mechanical speedocable output but all the VSS I have found that can bolt up have 4000 ppm or less so I am back to question 2.
Thanks
The vortec pcm is looking for an A/C SINE wave speed sensor signal, to my knowledge, the Chrysler products use a 3 wire hall effect type sensor, that outputs a SQUARE WAVE DC signal.
I am currently using a 8000 pulse/mile sensor (Dakota Digital) on my TH400 behind my 2005 5.3L with drive by wire. I have set the pulse input to about 3.8 pulse/drive shaft revolution, which makes the scan tool speed reading about accurate. I have noticed a little bit of roughness to cruise control, kind of searching for the correct speed at times...however it could be the old speedo cable in the 89 caprice.
I am currently using a 8000 pulse/mile sensor (Dakota Digital) on my TH400 behind my 2005 5.3L with drive by wire. I have set the pulse input to about 3.8 pulse/drive shaft revolution, which makes the scan tool speed reading about accurate. I have noticed a little bit of roughness to cruise control, kind of searching for the correct speed at times...however it could be the old speedo cable in the 89 caprice.
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Looks like the Dakota Digital sender will work for the VSS signal.
Now only need to figure out how to get the factory speedo to fire off the ECM output. Do you think this pull-up resistor mod will work for the speedo?
https://ls1tech.com/forums/conversio...s-learned.html
I have read that it might.
Now only need to figure out how to get the factory speedo to fire off the ECM output. Do you think this pull-up resistor mod will work for the speedo?
https://ls1tech.com/forums/conversio...s-learned.html
I have read that it might.
Best one Ive found. It uses the correct signal, with the correct 40 tooth reluctor ring and can be mounted anywhere along the driveshaft/axles
http://www.jagsthatrun.com/Pages/Par...ctor-Diff.html
http://www.jagsthatrun.com/Pages/Par...ctor-Diff.html
Looks like the Dakota Digital sender will work for the VSS signal.
Now only need to figure out how to get the factory speedo to fire off the ECM output. Do you think this pull-up resistor mod will work for the speedo?
https://ls1tech.com/forums/conversio...s-learned.html
I have read that it might.
Now only need to figure out how to get the factory speedo to fire off the ECM output. Do you think this pull-up resistor mod will work for the speedo?
https://ls1tech.com/forums/conversio...s-learned.html
I have read that it might.
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I think I have it figured out:
- The Jeep uses a 3 wire hall effect VSS that outputs a square wave @ 8000ppm. Since the Jeep speedo is spliced into the VSS signal wire the speedo must need a square wave @ 8000 ppm.
- The GM ECM has a square wave speedo output ,with software can be adjusted to 8000 ppm output.
I think if I use the Dakota Digital VSS to send a sine wave to run the ECM, then program the ECM for correct output to drive the speedo.
Sounds good to me in theory, will report back in a few weeks when I get it done.
- The Jeep uses a 3 wire hall effect VSS that outputs a square wave @ 8000ppm. Since the Jeep speedo is spliced into the VSS signal wire the speedo must need a square wave @ 8000 ppm.
- The GM ECM has a square wave speedo output ,with software can be adjusted to 8000 ppm output.
I think if I use the Dakota Digital VSS to send a sine wave to run the ECM, then program the ECM for correct output to drive the speedo.
Sounds good to me in theory, will report back in a few weeks when I get it done.
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UPDATE:
The speedometer works, so to recap for any Jeep Conversions this is what worked for my 92 YJ:
Dakota Digital 8 pulse speed sensor, running into the 06 PCM, PCM speedo output set to 8000 ppm. Runs the speedometer just fine, does not need a resistor pull up circuit.
The speedometer works, so to recap for any Jeep Conversions this is what worked for my 92 YJ:
Dakota Digital 8 pulse speed sensor, running into the 06 PCM, PCM speedo output set to 8000 ppm. Runs the speedometer just fine, does not need a resistor pull up circuit.
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So... I have a similar problem. I am using a Stak T-case in the FJ I have been working on, and it uses a Jeep Rubicon style Speed sensor. It is a hall effect Square Wave too. Unfortunately, the stak CANNOT support any type of gear driven speed sensor, so it has to use the one I have (the hall effect). I did purchase the Dakota Digital SGI-5 universal speed signal interface module since it is what Stak recommended. I pretty much have the speed sensor side figured out. It needs a 5 V power wire, a ground, and then the last wire is the signal out which goes to the interface module. However, I am a little confused... Is there a wire in the Chevy harness I can tap into to get the 5 V power I need for the sensor??? For those that don't know, the engine is an LQ4 6.0 from a 2003 Chevy truck. Also, in all data, it just lists a VSS low signal on pin 20 and a high signal on pin 21, both in the C2 connector (which just goes to the VSS plug at the transmission). I know that I need a Sine Wave signal, so thats why I got the interface, so that I could convert it from the square wave. However, I do not know if I need a 4000 PPM or 8000 PPM AC (sine wave) signal??? The interface module will do either. However, the tuner can help me with that part.
However, I do need to know which wire to use to inform the computer of the speed signal, the low signal wire? or the high signal wire? And also, as mentioned above, is there a 5 V wire that will be sufficient for powering the VSS, and which wire is it?
Guys, you don't know how much help you have been, I really appreciate it a lot!
However, I do need to know which wire to use to inform the computer of the speed signal, the low signal wire? or the high signal wire? And also, as mentioned above, is there a 5 V wire that will be sufficient for powering the VSS, and which wire is it?
Guys, you don't know how much help you have been, I really appreciate it a lot!
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So... I have a similar problem. I am using a Stak T-case in the FJ I have been working on, and it uses a Jeep Rubicon style Speed sensor. It is a hall effect Square Wave too. Unfortunately, the stak CANNOT support any type of gear driven speed sensor, so it has to use the one I have (the hall effect). I did purchase the Dakota Digital SGI-5 universal speed signal interface module since it is what Stak recommended. I pretty much have the speed sensor side figured out. It needs a 5 V power wire, a ground, and then the last wire is the signal out which goes to the interface module. However, I am a little confused... Is there a wire in the Chevy harness I can tap into to get the 5 V power I need for the sensor??? For those that don't know, the engine is an LQ4 6.0 from a 2003 Chevy truck. Also, in all data, it just lists a VSS low signal on pin 20 and a high signal on pin 21, both in the C2 connector (which just goes to the VSS plug at the transmission). I know that I need a Sine Wave signal, so thats why I got the interface, so that I could convert it from the square wave. However, I do not know if I need a 4000 PPM or 8000 PPM AC (sine wave) signal??? The interface module will do either. However, the tuner can help me with that part.
However, I do need to know which wire to use to inform the computer of the speed signal, the low signal wire? or the high signal wire? And also, as mentioned above, is there a 5 V wire that will be sufficient for powering the VSS, and which wire is it?
Guys, you don't know how much help you have been, I really appreciate it a lot!
However, I do need to know which wire to use to inform the computer of the speed signal, the low signal wire? or the high signal wire? And also, as mentioned above, is there a 5 V wire that will be sufficient for powering the VSS, and which wire is it?
Guys, you don't know how much help you have been, I really appreciate it a lot!
Options for using hall effect sensor:
-I think (but am not sure) you can send 12V to the hall effect sensor, the only problem I can see might be it having too much output voltage and burning up the Dakota Digital box.
-There are 5v reference sources on your PCM, look at the pin outs for an unused 5v output. Some sensors like oil pressure, map, tps, etc all use 5v reference, I don't see why you could not use one of these. For example, C1 pin 45 is 5v reference for the AC system you probably are not using.
-Another option for 5v would be to find an electronics voltage regulator that can regulate to 5v, I haven't looked but I bet this would be fairly easy to find.
Wiring the dakota digital box to you pcm via the 'high' wire, as the low is basically a ground. I am sure if you called Dakota they could verify this for you.
The pcm needs to know how many pulses per driveshaft revolution the vss outputs. This is determined by the tone ring in the transfercase. The ppm (pulse per mile) is calculated in the pcm based on tire/gear ratio. The pcm uses this calculation for the speedo output.
Good luck, let us know how it turns out.
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Gah, I love you guys! lol.
No A/C, so C1 connector Pin 45. Got it. I will use that to power the VSS. Also, it sends 3 pulses per driveshaft revolution, I verified that on the Stak4x4 website. And since Im here, do I need to hook up the "High" wire to the 4000 ppm location on the module of the 8000 ppm location? It would be great if I could get this wiring done tomorrow, it's going to the tuner on Wednesday morning!
No A/C, so C1 connector Pin 45. Got it. I will use that to power the VSS. Also, it sends 3 pulses per driveshaft revolution, I verified that on the Stak4x4 website. And since Im here, do I need to hook up the "High" wire to the 4000 ppm location on the module of the 8000 ppm location? It would be great if I could get this wiring done tomorrow, it's going to the tuner on Wednesday morning!
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do I need to hook up the "High" wire to the 4000 ppm location on the module of the 8000 ppm location?
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Well, I was able to get it all wired up. I took it to the tuner today and everything was as it should be. He made ~6 pulls on the dyno and was able to squeeze out ~400 HP at the crank. No bad for an engine with 100% stock internals.
I am planning on running a 5.3/turbo 350/ atlas in my jeep Commando and have been looking at the various vss options. Does the Dakota Digital 8k pulse generator for chrysler products fit an atlas transfer case which supposedly uses jeep 1987 and up speedometer gears? If so, I think I could just have the PCM program altered to work with this lower number of pulses, is this correct?
The other thing that is a little confusing is whether or not it will cause any issues when the transfer case is in low range. Some people say that the vss needs to be before the transfer case reduction while others say it doesn't matter if you are not using an electronic transmission. I believe the factory setup for four wheel drive locates the vss in the transfer case but uses a low range switch to let the PCM know when the transfer case is in low range.
If this setup would work should I have the PCM programmed to account for the 5:1 low range in the Atlas and use a switch so it knows when it is in low range, or if it wouldn't matter just don't worry about it. I don't need a speedometer, so as long as the engine would function correctly and not stall when I was in low range that would be ok.
Thanks for any suggestions or input.
The other thing that is a little confusing is whether or not it will cause any issues when the transfer case is in low range. Some people say that the vss needs to be before the transfer case reduction while others say it doesn't matter if you are not using an electronic transmission. I believe the factory setup for four wheel drive locates the vss in the transfer case but uses a low range switch to let the PCM know when the transfer case is in low range.
If this setup would work should I have the PCM programmed to account for the 5:1 low range in the Atlas and use a switch so it knows when it is in low range, or if it wouldn't matter just don't worry about it. I don't need a speedometer, so as long as the engine would function correctly and not stall when I was in low range that would be ok.
Thanks for any suggestions or input.
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Hi,
here a pic from my Homemade VSS on a 2002,LQ4,with aTH400 and a Dana 300 behind...runs perfect.
http://i547.photobucket.com/albums/h...00220_3193.jpg
Hardy
here a pic from my Homemade VSS on a 2002,LQ4,with aTH400 and a Dana 300 behind...runs perfect.
http://i547.photobucket.com/albums/h...00220_3193.jpg
Hardy
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hardy350,
that is one bad *** VSS. I was thinking of the same type of thing but could not find a cheap enough tone ring to use. What did you make your tone ring from and how did you attach it to your yoke?
that is one bad *** VSS. I was thinking of the same type of thing but could not find a cheap enough tone ring to use. What did you make your tone ring from and how did you attach it to your yoke?
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The other thing that is a little confusing is whether or not it will cause any issues when the transfer case is in low range. Some people say that the vss needs to be before the transfer case reduction while others say it doesn't matter if you are not using an electronic transmission. I believe the factory setup for four wheel drive locates the vss in the transfer case but uses a low range switch to let the PCM know when the transfer case is in low range.
If the atlas uses the 87 up Jeep speedo gears then the chevy vss should work. The gear housing and gears are intercahngable between a d300 and np231, the 87 up jeep vss just screws onto the speedo gear housing just like a cable.
You don't need to worry about the tranfercase low range because you are using a th350. The computer only needs to know the trans output speed on a computer controlled trans. VSS on the transfercase output will work just fine if you set computer to the proper pulse per revolution.
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I will make a Cover in the future for better looking...
Regards from Germany
Hardy
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Team ******,
I'm trying to hook up to the VSS in a Stak - can you tell me what color wires on the VSS go to what?
Thanks.
Stewart
I'm trying to hook up to the VSS in a Stak - can you tell me what color wires on the VSS go to what?
Thanks.
Stewart
So the computer wants an 8000 PPM signal, correct? And the computer outputs 4000 PPM to the factory GM speedo, correct?
If this is true, A Dakota Digital VSS will work, and an Autometer gauge will work.
Please, correct me if I am wrong. I have not called Dakota Digital or Autometer yet to verify this, was hoping one of you has some real world experience.
If this is true, A Dakota Digital VSS will work, and an Autometer gauge will work.
Please, correct me if I am wrong. I have not called Dakota Digital or Autometer yet to verify this, was hoping one of you has some real world experience.