A442F is picky about going into O/D (1 Viewer)

[ubguessin]

1993 1HD-T 353,000KM
Here's a list of things that have happened and what I have done so far.

1. Lost my gauge cluster and diagnosed a faulty speed sensor. while waiting on the new speed sensor to arrive I drove without it connected, I would get intermittent flashing of my O/D light but overdrive still worked.
2. New speed sensor showed up got everything installed and it was working great, NO O/D light flashing. O/D was working.
3. Outside air temperature dropped to about 7*F and now my O/D is being picky. Sometimes it works great other times i'm stuck in 3rd.
4. Ordered new Solenoid's installed them today. Filled with new fluid and went for a drive. Still no O/D. All other gears shift smooth. Outside air temps were in the 40'sF today. while inspecting the Transmission pan there were a few sparkles in the pan nothing terrible.

At this point I am at a loss.
Would I have another faulty speed sensor that is intermittently reporting the correct speed in order for it to go into O/D?
I do not know how to test the TCM. Does someone have a link to how this is done?
Could i just need to replace a wiring harness?\

All the help is appreciated. This is my daily and I've got travelling to do for the holidays, would love to have it working before the 22nd.

Thanks!

 

[Squash]

Tranny will not shift into hi until it warms up.

 

[ubguessin]

Tranny will not shift into hi until it warms up.

Yes I know this.

 

[Squash]

Tranny Temperature sensor as a wild guess.
I mean wild.

 

[ubguessin]

Tranny Temperature sensor as a wild guess.
I mean wild.

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What's the part # on that sensor?

 

[ubguessin]

Well yesterday and today after not having O/D at all for about 2 weeks the transmission decided yesterday afternoon and today until about 4 oclock that I was able to have O/D. So I am considering that I have either a fault in the valve body or the TCM.

 

[ubguessin]

Well yesterday and today after not having O/D at all for about 2 weeks the transmission decided yesterday afternoon and today until about 4 oclock that I was able to have O/D. So I am considering that I have either a fault in the valve body or the TCM.

Little update on the transmission O/D lockup conundrum. This past weekend I decided to install a transmission oil cooler. (Should have done this years ago) Before I installed the cooler the transmission was shifting to O/D "consistently". Outside air temp has been fluctuating from 19F to 60F. Whereas when it was really cold out it wouldn't lockup.

After installing the cooler the transmission has not shifted into O/D as of yet. I have ordered a Toyota OEM Transmission Temperature Switch 89428-60090. Hoping this may help as it seems OAT and being plumbed through the radiator allowed the transmission to run hotter allowing O/D lockup when OAT was warmer. I also ordered an extreme valve body, temp sensor & converter lockup switch from Australia theirs about 1.5 months before that arrives at my door. Will give another update in a week or so. After temp switch arrives.

 

[ubguessin]

Tranny Temperature sensor as a wild guess.
I mean wild.

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You may be right given my current update on this situation.

 

[ubguessin]

Tranny Temperature sensor as a wild guess.
I mean wild.

View attachment 3792598

View attachment 3792599

Does your book say when/what resistance this temp sensor sends a signal to the ECU? Was thinking of setting up a resistance plug to see if this tricks the ECU to think the transmission is "warm enough to shift to O/D"