Torque Converter Lock disengages constantly

[THE NEW GUY]

Hello there, I've noticed that my TC lock disengages constantly and more frequently then before, when I use the cruise control. Out of the cruise control, it works normally: it engages and keep engaged untill I floor the gas pedal or lower the speed bellow 65kmph.
If my throttle position sensor were wrong, woudn't it turn the CEL on?
thanks.

[Hocrest]

No, a TPS can be out of adjustment without throwing a code. Also, if your ATF is getting cooled too much it will unlock the TC.

[THE NEW GUY]

Originally Posted by Hocrest

No, a TPS can be out of adjustment without throwing a code. Also, if your ATF is getting cooled too much it will unlock the TC.

but it only happens when the cruise control takes control of the speed.
I had an external ATF cooler before, but I took it away when this problem started, (in july, at 40C here in Montreal) but still disengages. When it happen, I continue driving and after some minutes is engaged again, but only to restart the cicle once again...

[dcarrb]

Does it do this at any cruising speed, or within a narrow throttle range? If the latter, I second the TPS.

dcb

[BackWoodsBob]

Originally Posted by Hocrest

No, a TPS can be out of adjustment without throwing a code. Also, if your ATF is getting cooled too much it will unlock the TC.

Interesting. I have a 6 or 8 pass trans cooler and my TC would constantly go from lock to unlock. I wonder if this was the issue.
I installed a button that bypasses the TCU so I can lock it up manually .

[THE NEW GUY]

Originally Posted by BackWoodsBob

Interesting. I have a 6 or 8 pass trans cooler and my TC would constantly go from lock to unlock. I wonder if this was the issue.
I installed a button that bypasses the TCU so I can lock it up manually .

That's exactly what I was going to do, but then stops me the fact that I'll forget to disconect it whn slowing down the car... In adition, I like to find the WHY of the things...

[THE NEW GUY]

Originally Posted by dcarrb

Does it do this at any cruising speed, or within a narrow throttle range? If the latter, I second the TPS.

dcb

I'll confirm you this... Anyways, I find curious that always happen when in cruise control, not in normal.... If the TPS where the cause, why it does keep engaged in normal?
It is kind of hard to meassure the TPS resistance without removing it, and I do not want to remove it because it's a nigthmare to put it back at the good position. I connected two capacitors (2uF each) in series and the central point to the TPS cable that goes to the ECU. (carefull with the polarity). This arrangement was in parallel with the TPS and would smooth any disturbance on the signal due to a bad portion of the TPS. The result: still cycling disengage of the TC lock while in cruise control. I would discard the TPS failure... what do you think?

[Hocrest]

Follow the write up to test the TPS voltage. I think across has the link in his signature. If not, there's one in the how to docs. You want to check voltage across 2 of the wires with the car on.

[dcarrb]

Originally Posted by THE NEW GUY

I find curious that always happen when in cruise control, not in normal.... If the TPS where the cause, why it does keep engaged in normal?

First time I set the cruise on my silver SVX it immediately started "gear-hunting" like crazy. Subsequently I found that keeping the throttle out of a narrow band of travel (no problem unless stuck behind traffic moving at the offending speed) would make it behave. I never experimented with setting the cruise at a higher speed. A new TPS solved the problem.

dcb

[BackWoodsBob]

Originally Posted by THE NEW GUY

That's exactly what I was going to do, but then stops me the fact that I'll forget to disconect it whn slowing down the car... In adition, I like to find the WHY of the things...

I've only done that 1x. The torque of the EG just spun the lockup clutch and chugged like crazy, but didn't stall.

So far, trans fluid is still good and doesn't smell burnt. I placed the button next to my shifter so I rest my hand there for easy access.

[longassname]

Anybody that has a laptop with Windows can get the select monitor adapter from http://www.ecutune.com/ECUtuner.htm and an ftdi ttl-232r-5v usb cable from http://www.ftdichip.com/Products/Cab...BTTLSerial.htm and use the free ECUtuner software to propertly diagnose this kind of thing instead of playing guessing games for months.

You would be able to monitor whether the tcu is telling the torque converter to unlock or not and immediately know if there is a mechanical problem or not.

You would be able to monitor the sensor readings that would cause the tcu to tell the torque converter to unlock and quickly see exactly what sensor is the culprit.

That of course includes the tps so you wouldn't have to be at all competent with electrical diagnosis to check your tps. You could watch the exact readings the tcu gets as you press your accelerator and see if there are any bad spots or intermittent bad spots. Then if you had to replace your tps you could quickly adjust it exactly right--again seeing exactly what the tcu sees.

If you have a laptop it's crazy not to have the ECUtuner software and select monitor interface.

[icingdeath88]

Originally Posted by longassname

Anybody that has a laptop with Windows can get the select monitor adapter from http://www.ecutune.com/ECUtuner.htm and an ftdi ttl-232r-5v usb cable from http://www.ftdichip.com/Products/Cab...BTTLSerial.htm and use the free ECUtuner software to propertly diagnose this kind of thing instead of playing guessing games for months.

You would be able to monitor whether the tcu is telling the torque converter to unlock or not and immediately know if there is a mechanical problem or not.

You would be able to monitor the sensor readings that would cause the tcu to tell the torque converter to unlock and quickly see exactly what sensor is the culprit.

That of course includes the tps so you wouldn't have to be at all competent with electrical diagnosis to check your tps. You could watch the exact readings the tcu gets as you press your accelerator and see if there are any bad spots or intermittent bad spots. Then if you had to replace your tps you could quickly adjust it exactly right--again seeing exactly what the tcu sees.

If you have a laptop it's crazy not to have the ECUtuner software and select monitor interface.

It can do logging right?

[THE NEW GUY]

Originally Posted by longassname

Anybody that has a laptop with Windows can get the select monitor adapter from http://www.ecutune.com/ECUtuner.htm and an ftdi ttl-232r-5v usb cable from http://www.ftdichip.com/Products/Cab...BTTLSerial.htm and use the free ECUtuner software to propertly diagnose this kind of thing instead of playing guessing games for months.

You would be able to monitor whether the tcu is telling the torque converter to unlock or not and immediately know if there is a mechanical problem or not.

You would be able to monitor the sensor readings that would cause the tcu to tell the torque converter to unlock and quickly see exactly what sensor is the culprit.

That of course includes the tps so you wouldn't have to be at all competent with electrical diagnosis to check your tps. You could watch the exact readings the tcu gets as you press your accelerator and see if there are any bad spots or intermittent bad spots. Then if you had to replace your tps you could quickly adjust it exactly right--again seeing exactly what the tcu sees.

If you have a laptop it's crazy not to have the ECUtuner software and select monitor interface.

Mike, let me get it straigth, The select monitor adapter is RS232 and I'll need the RS232 to USB port adapter also. rigth?

[dragoontwo]

The cable has a built in RS-232 to USB converter. The non USB end should plug directly into the ECUTuner

[BackWoodsBob]

Originally Posted by longassname

Anybody that has a laptop with Windows can get the select monitor adapter from http://www.ecutune.com/ECUtuner.htm and an ftdi ttl-232r-5v usb cable from http://www.ftdichip.com/Products/Cab...BTTLSerial.htm and use the free ECUtuner software to propertly diagnose this kind of thing instead of playing guessing games for months.

You would be able to monitor whether the tcu is telling the torque converter to unlock or not and immediately know if there is a mechanical problem or not.

You would be able to monitor the sensor readings that would cause the tcu to tell the torque converter to unlock and quickly see exactly what sensor is the culprit.

That of course includes the tps so you wouldn't have to be at all competent with electrical diagnosis to check your tps. You could watch the exact readings the tcu gets as you press your accelerator and see if there are any bad spots or intermittent bad spots. Then if you had to replace your tps you could quickly adjust it exactly right--again seeing exactly what the tcu sees.

If you have a laptop it's crazy not to have the ECUtuner software and select monitor interface.

I would love to run a select monitor app and monitor my engine.
Sadly the guy that thinned my harness for the swap cut the select monitor off. I have no idea which 2 wires go where with your adapter