This TX has solenoids for Overdrive and for the Lock up torque converter.
They Look like this:
OD will usually engage over 27MPH under light throttle, and it still does this when cold.
Once warm at a steady 35MPH it will drop back into third, then back into OD, in out, in out until I press the OD OFF button. Then Speed up to 40mph and it either will not go into OD, or it will and act normally, until speed drops to 35mph at which point the IN/out in/out resumes/continues.
Usually it would only drop out of OD on Decel at 26MPH. The factory service manual confirms this behavior as normal and expected.
So far what I have done is ensure the wiring harness from back to engine to the Tx, and those two connectors, are not the issue.
I have not dropped the pan.
Last June was the last TX service. The ATF+4 was still pink and sweet smelling, the filter was not grey, there was only a little ferrous fuzz on the magnets. I removed a weeping magnefine filter and installed a Derale remount mount spin on filter with XG16 plumbed after the additional cooler. It has about 80K miles on it since it was rebuilt, and perhaps 3 to 3.5 K miles since last June when I dropped the pan, changed in pan filter, and magnets cleaned and installed new steel cooler lines and the remote mount filter.
There are no computer codes related to the transmission. Only a code 12, 33, 53 and an end of codes 55, though 53 is an internal engine computer fault detected. Code 53 has been there for 12 years. 33 is related to the AC relay, which is unplugged as I have No AC anymore.
I do not really know how to proceed, whether the issue is the solenoids or the wiring between them and the engine computer, or the drivers for them in the engine computer, or perhaps something more dire, like the Overdrive piston selection thrust plate.
Any Ideas?
The factory service manual states that engine computer checks the engine Coolant temp sensor for 60F+, the engine speed sensor, vehicle speed sensor, throttle position sensor, and MAP sensor, to activate overdrive.
I am getting no codes related to any of these sensors, and the engine has been running well.
Any Ideas on how to proceed with Diagnosis?
They Look like this:
OD will usually engage over 27MPH under light throttle, and it still does this when cold.
Once warm at a steady 35MPH it will drop back into third, then back into OD, in out, in out until I press the OD OFF button. Then Speed up to 40mph and it either will not go into OD, or it will and act normally, until speed drops to 35mph at which point the IN/out in/out resumes/continues.
Usually it would only drop out of OD on Decel at 26MPH. The factory service manual confirms this behavior as normal and expected.
So far what I have done is ensure the wiring harness from back to engine to the Tx, and those two connectors, are not the issue.
I have not dropped the pan.
Last June was the last TX service. The ATF+4 was still pink and sweet smelling, the filter was not grey, there was only a little ferrous fuzz on the magnets. I removed a weeping magnefine filter and installed a Derale remount mount spin on filter with XG16 plumbed after the additional cooler. It has about 80K miles on it since it was rebuilt, and perhaps 3 to 3.5 K miles since last June when I dropped the pan, changed in pan filter, and magnets cleaned and installed new steel cooler lines and the remote mount filter.
There are no computer codes related to the transmission. Only a code 12, 33, 53 and an end of codes 55, though 53 is an internal engine computer fault detected. Code 53 has been there for 12 years. 33 is related to the AC relay, which is unplugged as I have No AC anymore.
I do not really know how to proceed, whether the issue is the solenoids or the wiring between them and the engine computer, or the drivers for them in the engine computer, or perhaps something more dire, like the Overdrive piston selection thrust plate.
Any Ideas?
The factory service manual states that engine computer checks the engine Coolant temp sensor for 60F+, the engine speed sensor, vehicle speed sensor, throttle position sensor, and MAP sensor, to activate overdrive.
I am getting no codes related to any of these sensors, and the engine has been running well.
Any Ideas on how to proceed with Diagnosis?
