Does torque converter lock up with no speed sensor input?

[GNWRXRon]

I just read the Kirban Performance news letter that contained the following
information.

"Rick, a customer of mine who had a GNX styled dash
installed noticed that on the highway
his transmission temp. would be around 230 degrees.
He contacted his local transmission shop and they told him
it should be under 200 degrees. It turns out his VSS-Vehicle
Speed Sensor was not hooked up. This sensor relays the cars
speed to the ECM. Without this sensor the computer
would not lock up the torque converter with the TCC
Solenoid. Your torque converter should lock up around
45 mph. A transmission shop would be able to
explain it better if its something you are not sure
of. If you have the GNX style dash you can contact
Rick who gave me this info for the fix."

Well, my car also has the GNX aftermarket dash. My transmission does not tend to overheat. However, there is a very large aftermarket transmission cooler installed on my car. When I installed a new cruise control switch stalk recently my cruise control still did not work. The shop that installed my switch said that their scan indicated that there was no speed sensor input. My miledge is in the low to mid teens and other owners have told me they are in the 20s. I am thinking that my torque converter may very well not be locking up at any speed.

What is the fix?

 

[cottonpicker14]

Not sure if this is what you mean about a fix, but my speed sensor was disconnected and I was told that I could manually engage the torque converter by jumping two of the ALDL ports. What I did was put a wire in the top left and top right with a toggle switch in between. When I reached around 50 mph, I put the toggle switch in the up position and the converter would lock up. When I slowed down, I just put the toggle to the down position to unlock it.
It worked because when I put the toggle up, the rpms dropped about 400 rpms. It took about 20 minutes to hook it up.
Hope this helps

 

[GNWRXRon]

Thanks COttonpicker

That makes sense but I would like my cruise control to work as well. I am thinking more of a aftermarket speed sensor that will work with the GNX dash.

 

[pacecarta]

check your speedo cable where the upper and the lower meets by the wiper motor , do you have a VSS speed sender there ?

when you replace the stock gauges with the gnx style you loose the factory vss optical pickup point which is in the speedo head

for lockup to occur you need to have the vss sender installed and best place for it is where lower cable comes up onto the fenderwell underthe hood

VDO and others sell vss senders that will replace the optical portion of the factory unit and you just cut the optical cable from the factory unit and splice in the vdo sender . on the gnx dash i have the VSS included the upper cable needed to connect to the VDO speedo
on the cyberdyne i pulled the stock speedo apart and removed the pointer ,odometer and face section and retained the optic portion so the vss signal wouldnt be lost

if you dont have an operating VSS you wont have lockup unless you manually engage it by grounding pin F of the aldl connector .
i guess it could heat up your tranny fluid driving at lower rpms if the converter is inefficent and relys on the lockup to get close to a 1:1 match of the flywheel to input to the trans . theres lots non lockup converters running in buicks , but an external tranny cooler is always a good idea

 

[Ormand]

The stock TC is pretty inefficient down around 2000 rpm. Unfortunately, that is often a good cruising rpm, so you will heat the trans fluid if the TCC doesn't lock up for cruising. With an aftermarket TC, it will depend on the way the TC was set up, and it may be better or it may be worse. I would have thought that the stock transmission cooler would handle the heat from cruising, but maybe not..

 

[GNut]

The Fix

The fix is using the correct VSS for a GNX dash setup. DO NOT buy just any VSS from VDO, Autometer, etc... THEY WILL NOT WORK!! The GN/TR ECM requires a VSS that produces 2000 pulses per mile. At 60mph, the speedo cable is spinning at 1000 rpm (on a stock GN setup of course, 3:42 rear gear, 26" tall tire, 200R4 trans). You MUST use a 2 pulse VSS!!! (1000 rpm x 2 pulses per revolution = 2000 pulses) Most after market VSS's are either an 8 or 16 pulse per revolution 3 wire Hall effect transducer. John Spina at Casper's makes an adapter that these hall effect VSS's will work with or you can get a 2 pulse from me. I have them made and use them for EVERY GNX style dash I build. I've been building panels that WORK for over 10 years now and fixing other builders mistakes for almost as long. Who am I?

Tom Houser
Performance Instruments
www.gnxdash.com