LS factory cruise control hook up

[valis4nu]

I am in the process of designing and building a tester module for this model of cruise control module (CCM) as I have replaced it twice on my 92 Buick Roadmaster without success. The only thing I am not sure about is how to simulate the input from the PCM (VSS) that goes into Terminal K (green wire) of the CCM. I know that it is a 5-volt signal, but that is all.

I found a GM video on YouTube regarding this CCM on a 91-93 Buick Roadmaster. It stated that the Speed Sensor Module (SSM) on the driveshaft produces an AC voltage of anywhere from 2-100 VAC. This signal is fed into the Vehicle Speed Sensor (VSS) which in turn feeds Terminal K on the CCM. But the video confused me on one point in that it stated that the voltage of that wire is actually a ratio of 1.1 volts per 1 mph.

Here is the link to that video:
https://www.youtube.com/watch?v=Q5SEy9GwQIw

Advice and suggestions are most welcomed. Thanks!

[y5mgisi]

How's aboot an actual speed sensor from jags that run? You could hook it up to a drill motor or something to spin it.

[y5mgisi]

Here is there info page.

http://www.jagsthatrun.com/Pages/Spe...eedometer.html

[valis4nu]

Originally Posted by y5mgisi

How's aboot an actual speed sensor from jags that run? You could hook it up to a drill motor or something to spin it.

That actually sounds like it would be more complex than just rigging up some kind of a signal simulator. If you look at the VSS speed sensor module, there are all kinds of wires running in and out of it. I don't know that one could easily jury-rig up a circuit through it and get it to work properly. All I need is something that will provide a valid speed signal to terminal K so that I can press the Set button and engage the cruise control module. Then I can vary the speed signal up and down to see that the stepper motor is indeed trying to make adjustments.
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[ls1nova71]

I dont think either way is going to work. These things are very sensitive so just wiring it up and not being on a vehicle, it will likely not do anything. You cant even get one to work on a car that is on jack stands because as soon as it sets, its already going faster than the set speed and will instantly kick back off. As easy as these things are to put on a car, that's going to be your best tester.

[y5mgisi]

Just to be clear, im talking about a sensor like this.



Then, if you needed to, it would be super easy to wire it to a gm DRAC module and the module would put out the proper VSS signal.

[valis4nu]

Originally Posted by y5mgisi

Just to be clear, im talking about a sensor like this.

Then, if you needed to, it would be super easy to wire it to a gm DRAC module and the module would put out the proper VSS signal.

I'm not sure what a DRAC module is. In any case, I'm thinking that this may be more trouble than what it's worth. I would like to know what the signal is that goes to Terminal K, though. If it is simply a matter of an on/off pulse current of 5V, then I can rig up a small motor to do that.
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[valis4nu]

Could you please explain to me what the DRAC module is and just how you would wire it so as to provide the proper signal to Terminal K on the CCM? Thanks!

[YOUSTB2WD]

My cruise quit working because I have no speedo signal coming out of the PCM. I tested my signal generator and it worked fine and the wires to the PCM have continuity. Is there anyway to test the output signal from the PCM?

[Hart_Rod]

Originally Posted by YOUSTB2WD

My cruise quit working because I have no speedo signal coming out of the PCM. I tested my signal generator and it worked fine and the wires to the PCM have continuity. Is there anyway to test the output signal from the PCM?

You would need an oscilloscope to check the output signal from the computer.

[y5mgisi]

The drac module is an original piece of gm equipment. I think it was used on all tbi motors. But it's what accepts the vss signal on the tbi motors and sends out information to the cruise, speedo, and ecm on those tbi systems.

[y5mgisi]

You can also break into them and change stuff around to account for different gear ratios and tires diameters.

[y5mgisi]

Here's some more info on them. They are super simple, plentiful, and cheap and I think they could easily be made to work for cruise and speed sensor input for the guys still running cable speedos. And I think this would even make it easy to add the newer style cruise control module to an older carbed vehicle.

http://614streets.com/drac.html

[YOUSTB2WD]

I have a 200R4 behind an LT1 ,there is no signal being generated by the transmission, I have a Dakota Digital signal generator hooked up to the speedo output on the transmission. I know the signal is being delivered to PCM.

[Hart_Rod]

Originally Posted by XwalkerX

I NOW HAVE WORKING CRUISE CONTROL IN MY 44 YEAR OLD TRUCK!



thank you for all the help along the way LS1NOVA!!!!!!

What was the fix?

[ls1nova71]

Originally Posted by Hart_Rod

What was the fix?

IIRC he ended up having LED brake lights installed by the previous owner. What's your issue, I see you've posted on several cruise threads?

[Hart_Rod]

Originally Posted by ls1nova71

IIRC he ended up having LED brake lights installed by the previous owner. What's your issue, I see you've posted on several cruise threads?

I can't get cruise lockout to toggle to "NO". Everything else checks good. I think its because of my LED tail lights. Will check it out tomorrow.

[Hart_Rod]

I was able to wire a regular bulb into my 3rd brake light system to verify that the LED tail lights were causing the problem, the CC works perfect now. I'm going to try one of the LED flashers and see it that will work before I wire in another relay, I already have a enough relays as it is under the dash.......

[Deron5]

Thanks to all the great info here I now have working cruise control

[solidaxel]

Welcome from So Arizona!
Where is Bear de?
I hope you find what you are looking for in this site, a lot of helpful folks on here

[Deron5]

Originally Posted by solidaxel

Welcome from So Arizona!
Where is Bear de?
I hope you find what you are looking for in this site, a lot of helpful folks on here

Thanks
Delaware east coast

[reaper71]

LS1NOVA71 do you still have the smooth switch for sale?

Mark

[bdjptm]

Do you have a bigger picture? Looks like Pin "G" is 12V until the pedal is pressed - Normally closed, Pin D is 12V when the brake pedal is pressed - normally open. Am I right on this?

[ls1nova71]

Originally Posted by bdjptm

Do you have a bigger picture? Looks like Pin "G" is 12V until the pedal is pressed - Normally closed, Pin D is 12V when the brake pedal is pressed - normally open. Am I right on this?

Just the opposite, G is 12v when the pedal IS depressed, and D Is 12v when the pedal is NOT depressed.

[ls1nova71]

Originally Posted by reaper71

LS1NOVA71 do you still have the smooth switch for sale?

Mark

Sorry but I have not been able to find any parts to put any together latley. The supply of 30 plus year old vehicles in the junk yards is drying up.