Autometer Speedo Doesnt operate?
And when you call them to tell them its messing up your trans shifting they will tell you to try several different resistors. I did that and it worked better, but still wasn't right.
When you calibrate it, does the odometer count off pulses? Mine wouldn't move when I switched it either, but after driving it and calibrating it to 4000 pulses it worked.
When you calibrate it, does the odometer count off pulses? Mine wouldn't move when I switched it either, but after driving it and calibrating it to 4000 pulses it worked.
Now I need to figure out WTF on the TACH. V8 mode is too low, V4 is too high, V6 still seems off, but closer.
I installed my autometer ultra lite speedo off the ecm yesterday and it works perfectly as well.
Edit: Noticed you got yours working.
Did you set your tach to 4 cylinder? That did the trick for mine.
Edit: Noticed you got yours working.
Did you set your tach to 4 cylinder? That did the trick for mine.
I put it in 6 cylinder mode and the idle RPM is correct, but throughout the range is not.
Teching In
Joined: Dec 2012
Posts: 1
Likes: 0
Great information in this thread, but I still have some questions. Engine and PCM are 2004 LQ4 with a 4L80E transmission; Speedometer is an Autometer Sport Comp Programmable unit.
Q1: When Autometer says to connect directly to the VSS signal, what does that mean for a two-wire (VSS low signal wire and VSS high signal wire) sine-wave signal coming off the tranny or transfer case?
Q2: If one uses the "VSS Out 4k/mile" (PCM Green Pin 50) signal as suggested, how do you calibrate the speedometer to "4000 pulses". Does that mean instead of driving for 2 miles per Autometer instructions, you drive until the odometer reads 8000 pulses?
Q3: What is the PCM output on Pin 49 of the Green connector (VSS Out 129k/mile) used for?
Thanks in advance
Q1: When Autometer says to connect directly to the VSS signal, what does that mean for a two-wire (VSS low signal wire and VSS high signal wire) sine-wave signal coming off the tranny or transfer case?
Q2: If one uses the "VSS Out 4k/mile" (PCM Green Pin 50) signal as suggested, how do you calibrate the speedometer to "4000 pulses". Does that mean instead of driving for 2 miles per Autometer instructions, you drive until the odometer reads 8000 pulses?
Q3: What is the PCM output on Pin 49 of the Green connector (VSS Out 129k/mile) used for?
Thanks in advance
Last edited by Medusa; Mar 10, 2013 at 08:20 PM.
To answer your questions, Q2. It means tap directly into the high side wire of the VSS, I wouldn't recommend it, as it can cause problems. Q2, when in calibration mode, you would drive until it reads 4000 pulses in the odometer. Q3 Its for tABS, don't use it for a.speedo.
I think this thread may have solved my issue, my speedo is tapped straight into the VSS and I have all kinds of funky shifting issues making me think the tranny was bad.
Going to re-wire it directly into the PCM output tonight and see how she runs.
Going to re-wire it directly into the PCM output tonight and see how she runs.
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I have another twist to the speedometer issue and hopefully you experts can help. For various reasons, which are irrelevant, I want to run the speedo off the ABS sensor that is in my C6 hubs. I have ATS spindles on my GTO and they hubs have a built in sensor already in place. There are two wires coming off that sensor, and after doing some looking around I found the the reluctor wheel inside the hub has 48 teeth.
I have the GMPP harness and according to the wiring diagram it can use the VSS, but it is optional. Indeed, I have been running for a few years now without the VSS input into the ECU and it runs fine, but on occasion, it will want to die when I come to a stop. I think adding the VSS signal will help this.
According to stock Corvette wiring, it doesn't make any difference which wire off the ABS sensor is "Hi" or "Low."
So what do you guys think, can I run the two wires off the ABS sensor to the ECU VSS plug? Can I tap the "Hi" side and run that to my AutoMeter speedo? I am not worried about messing up shifting because I have a manual trans (Richmond).
Any input is welcome.
Andrew
I have the GMPP harness and according to the wiring diagram it can use the VSS, but it is optional. Indeed, I have been running for a few years now without the VSS input into the ECU and it runs fine, but on occasion, it will want to die when I come to a stop. I think adding the VSS signal will help this.
According to stock Corvette wiring, it doesn't make any difference which wire off the ABS sensor is "Hi" or "Low."
So what do you guys think, can I run the two wires off the ABS sensor to the ECU VSS plug? Can I tap the "Hi" side and run that to my AutoMeter speedo? I am not worried about messing up shifting because I have a manual trans (Richmond).
Any input is welcome.
Andrew
Interesting idea. I would imagine it could be made to work, but would think you would have to verify that you could change the VSS input into the PCM to be able to read it right. ABS uses a lot more pulses per mile and if you just hook it to the PCM its going to think you're going 300mph at around 70mph. 
Then you would have to make sure the Autometer speedo could be calibrated tor that many PPM. I think they can be programmed for a lot more so that may not be a problem. If you try it, keep us informed, I'd kind of like to know if it would work too since the newer PCMs don't have a normal speedo output on them, it could be an alternative. I have heard of at least one person who used an 8.8 Ford rear end with the speed sensor on the housing wired up to run a speeso.
Then you would have to make sure the Autometer speedo could be calibrated tor that many PPM. I think they can be programmed for a lot more so that may not be a problem. If you try it, keep us informed, I'd kind of like to know if it would work too since the newer PCMs don't have a normal speedo output on them, it could be an alternative. I have heard of at least one person who used an 8.8 Ford rear end with the speed sensor on the housing wired up to run a speeso. 
Well, for anyone that is interested. I got it wired up with one side of the ABS sensor going to ground and the other sending a signal to the speedo. I wired it up temporarily, just to see if it was working. I set my Autometer speedo into calibration mode and moved the car forward about 4 feet, hoping that I could see the pulses being counted on the odometer readout. Unfortunately, this didn't happen.
I called Autometer tech support and was told that this should work, but he indicated that the car might have to move a little bit for the sensor to start generating a signal. I will try this again, and will jack up that wheel and see if I can get a signal by spinning the wheel by hand.
Andrew
I called Autometer tech support and was told that this should work, but he indicated that the car might have to move a little bit for the sensor to start generating a signal. I will try this again, and will jack up that wheel and see if I can get a signal by spinning the wheel by hand.
Andrew
For anyone that cares, this works like a charm.
Dorman sells the ABS jumper harness that fits the C5/6 ABS sensor: PN 970-007.
One of the leads needs to be grounded, while the other lead is the signal wire. It doesn't matter which is which. Run the signal wire to the Autometer gauge and recalibrate. The ABS sensor will start sending pulses after 2-3 turns of the wheel.
The C5/6 hubs have a 48 tooth reluctor wheel. I am running 255/40-18 tires in the front, which according to TireRack, are 801 turns per mile, so for the two mile calibration period, they will turn 1602 times.
1602 x 48 = 76,896 pulses per 2 miles. Having that information, you don't even need to measure out an accurate 2 mile stretch of road. I started my calibration and when the counter on the speedo got to 76,000 I stopped it. I compared the speedo reading to the GPS reading on my phone and the speedo was slow by about 2 mph. I assumed that the GPS is accurate. So I repeated the calibration and stopped it when the counter got to 74,000 and now the speedo reads exactly the same as the GPS.
Andrew
Dorman sells the ABS jumper harness that fits the C5/6 ABS sensor: PN 970-007.
One of the leads needs to be grounded, while the other lead is the signal wire. It doesn't matter which is which. Run the signal wire to the Autometer gauge and recalibrate. The ABS sensor will start sending pulses after 2-3 turns of the wheel.
The C5/6 hubs have a 48 tooth reluctor wheel. I am running 255/40-18 tires in the front, which according to TireRack, are 801 turns per mile, so for the two mile calibration period, they will turn 1602 times.
1602 x 48 = 76,896 pulses per 2 miles. Having that information, you don't even need to measure out an accurate 2 mile stretch of road. I started my calibration and when the counter on the speedo got to 76,000 I stopped it. I compared the speedo reading to the GPS reading on my phone and the speedo was slow by about 2 mph. I assumed that the GPS is accurate. So I repeated the calibration and stopped it when the counter got to 74,000 and now the speedo reads exactly the same as the GPS.
Andrew
Teching In
Joined: Feb 2012
Posts: 3
Likes: 0
From: Texas
For anyone that cares, this works like a charm.
Dorman sells the ABS jumper harness that fits the C5/6 ABS sensor: PN 970-007.
One of the leads needs to be grounded, while the other lead is the signal wire. It doesn't matter which is which. Run the signal wire to the Autometer gauge and recalibrate. The ABS sensor will start sending pulses after 2-3 turns of the wheel.
The C5/6 hubs have a 48 tooth reluctor wheel. I am running 255/40-18 tires in the front, which according to TireRack, are 801 turns per mile, so for the two mile calibration period, they will turn 1602 times.
1602 x 48 = 76,896 pulses per 2 miles. Having that information, you don't even need to measure out an accurate 2 mile stretch of road. I started my calibration and when the counter on the speedo got to 76,000 I stopped it. I compared the speedo reading to the GPS reading on my phone and the speedo was slow by about 2 mph. I assumed that the GPS is accurate. So I repeated the calibration and stopped it when the counter got to 74,000 and now the speedo reads exactly the same as the GPS.
Andrew
Dorman sells the ABS jumper harness that fits the C5/6 ABS sensor: PN 970-007.
One of the leads needs to be grounded, while the other lead is the signal wire. It doesn't matter which is which. Run the signal wire to the Autometer gauge and recalibrate. The ABS sensor will start sending pulses after 2-3 turns of the wheel.
The C5/6 hubs have a 48 tooth reluctor wheel. I am running 255/40-18 tires in the front, which according to TireRack, are 801 turns per mile, so for the two mile calibration period, they will turn 1602 times.
1602 x 48 = 76,896 pulses per 2 miles. Having that information, you don't even need to measure out an accurate 2 mile stretch of road. I started my calibration and when the counter on the speedo got to 76,000 I stopped it. I compared the speedo reading to the GPS reading on my phone and the speedo was slow by about 2 mph. I assumed that the GPS is accurate. So I repeated the calibration and stopped it when the counter got to 74,000 and now the speedo reads exactly the same as the GPS.
Andrew
Just wanted to say Thank you for the info on this Project GotTagO.
Hey ! This really does work ! I had been saving this thread on my desktop for a year and now I finally got to try it out. I have an 86 corvette and I am using the factory abs wheel sensor. I have not actually calibrated the speedometer yet because the car does not run but I did get the needle to move with a quick temporary calibration and spinning the wheel by hand with it off the ground. I feel sure it will calibrate fine when I can drive the car.
Just wanted to say Thank you for the info on this Project GotTagO.
Just wanted to say Thank you for the info on this Project GotTagO.
Andrew
