1998 Mercury Villager service engine soon light

code that shows is P0744

Hi prp2298, Thank you for the donation. Here is a description of the problem and diagnostic procedures. DTC P0744/1107: TCC SOLENOID VALVE Circuit Description DTC is set when improper shifting to 4th gear position or improper torque converter clutch operation is detected. Problem is NOT caused by electrical failure of A/T circuits but by mechanical failure. Control valve sticking, improper solenoid valve operation, malfunctioning oil pump or torque converter clutch etc.

All of this has been done. Trans. had a full rebuild, including solenoid and valve bedy, the solenoids and valve body were replaced again, same problem every time. Light was coming on in same fashion, ie driving conditions before trans rebuild. Any other ideas?

Were you able to erase the DTC prior to testing?

In your 1st post,

" Light comes on when driven at highway speeds for a short time , 15 to 20 minutes, then slow down. Light comes on when you go to speed up again. "

Does the above mean the light went off and came back ON?

Something could have been missed out during the rebuild.
Were the oil pump and torque converter clutch checked?

Were the line pressure tested?

Light comes on after driving at highway speeds then slowing down and speeding up again. It does not go out and come back on. Converter clutch was replaced, line pressure all shows normal. Any way this can be a faulty sensor? I am $2800.00 in to this, would like to fugure it out.

Should also mention that when light comes on no difference in drivability is noticed. Shifts through all gears, including overdrive crisply and with no hesitation. Have noticed that when shifting from park overdrive off light comes on untill tapping button on end of shift lever.

A faulty sensor would cause other codes to appear and since you are not gettiing any other codes, that should not be the cause. The OD light coming on when shifting out of P could mean a fault in the OD circuit or switch. Maybe you can try a manual code retrieval to see if there are any codes stored. I am not able to upload the codes charts now as there seems to be some problem with my connections and will do so later.

No codes stored. No drivability issues, suggestions? open to anything.

You mentioned SES light showing and no codes stored?

No driveability issues?

Shows P0744, no others. When light comes on, stays on, there are none changes whatsoever in drivability. Tranny shifts fine through all gears. P0744 is Torque Converter Clutch Circuit Intermittent on list. Clutch was replaced in rebuild.

I seem to be running out of options.

From the data available to me, P0744 does not necessarily mean the torque converter clutch alone. It mentioned improper shifting to 4th or improper clutch operations.

As you do not have shifting issues, the torque converter clutch should be the cause as it involves only very minimal shifting and might not be noticeable.

Were those parts replaced new or used?
There could be the possibility of a faulty torque converter.

replaced new. Maybe just a faulty part.

I would be doing additional research on this and would try to get back to you asap.

Meanwhile I will post it in the moderators forum to get additional technicians involved to try to solve this problem for you.

Thank you, anything will be greatly appreciated.

Hi
Been follow your posts got an idea what might be going on . Need to know if you did the TCM selfdiagnoses test and did long pulse occure in flash #7?
Let me know

seems there was long pulse, any ideas?

Which of the following conditions described the pulse that you are getting?

overdrive off light is not flashing. sometimes comes on when shifting into gear, goea off with tap to button on end of shifter. Overdrive off function works well at all times, even when service soon light is on.

You need to go into TCM diagnostic modes to get the OD light to flash.

Refer to previous replies I made.

You did the test and there was a long flash on seventh pulse. If yes then there is a hard part failure in trans ie convertor,solenoid, oil pump, ring seals on input shaft damaged during rebuild. Hope you got a warrenty because it needs to come back out and problem found.

Thanks,
Will check out the warranty as it is back in the shop this am.
A chance to see how good my warranty really is.

Thanks for all the help, it is appreciated.

Good luck lets us know what they come up with.Will advise if it seems right.

Just got call from shop. They said internal split shaft with three oil seals had center seal bad which is causing problem. They are in the process of replacing it now. Say it takes a total teardown of tranny again.
Sound like this could be it?

Yes indeed check post May 13,2:31 see I mentioned the oil seals That is what they found.

Good Call, sounds like you were right on the money. Where are you located? You said check the 2:31 answer, but it got to me here in Wa. state at 10:31.
Thanks again.

FLORIDA