Autotrans lock up

[bertha66]

First question; I have a 93 SHO 3.2 with the ATX, does it have a torque converter lock up and second question; if it does what controls it?

 

[Fordlover96]

It most certainly does have torque converter lockup! The parts that controls is it is the PCM, i believe. It tells the torque converter lockup clutch and solenoid based on speed and engine load.

 

[bertha66]

It most certainly does have torque converter lockup! The parts that controls is it is the PCM, i believe. It tells the torque converter lockup clutch and solenoid based on speed and engine load.

Thank you, so where is the solenoid at? Is it assessable from the out side of the trans?

 

[Dirk37]

The second generation SHO's have the AX4S transmissions which do have a TC lockup.

Someone will have to confirm this but I believe it has the same control as an AX4N. To control the AX4N, there is a small harness that goes into the top of the transmission. There are wires for power, the shift solenoids, and the TC Lockup. The TC lockup usually has 14 volts (or whatever the alternator is putting out) going to it when it's unlocked, but when it's locked it drops down to around 12 volts.

What I'd do is splice into that wire, then connect a volt meter and go for a cruise watching the voltage move between two values. Then to control it, you could hook up a relay that switches the input through a voltage divider to drop the voltage.

I'd recommend reading up on how the transmission works internally if you want to control it. I know all of this from building a little circuit with LED's that shows what gear the car is in and if the TC is locked or not, I never tried to actually control the transmission for fear of damaging it.

 

[bertha66]

Thank you guys, I will check that.

 

[Dirk37]

Here's the wiring diagram for the connector, if I remember correctly it's on top of the trans under the throttlebody.

Here's a great article on how the TC lockup works, the reason why the voltage is reduced rather than just on or off is because there are various stages of lockup. I have no idea what voltage corresponds to which stage though.

http://www.sonnax.com/system/pdfs/111/original/TS5-GN-098-099.pdf

 

[rubydist]

The place to start is by pulling codes from the pcm - that will tell you if it is complaining about anything including tc lockup. if it is trying to lock and not being successful, there will be a corresponding code.

what are the codes?

 

[msteiny]

Have you done anything to the cooling lines from the transmission? Like remove the thermostat and plumb the lines directly to the cooler. If the transmission does not get warmed up the torque converter will not lock up.