Complete Transmission Flush DIY - VIDEO

[Sajan]

I was trying to figure out what this detection mode does..and whether you just need to monitor the ATF temp.

This is how you get into the ATF detection mode for techstream..

(2) Turn the engine switch on (IG) and turn the Techstream on.
(3) Enter the following item: Powertrain / ECT / Active Test / Connect the TC and TE1.
(4) Select the Active Test item: Connect the TC and TE1 / ON.
(5) Select the Data List item: A/T Oil Temperature 1.
(6) Check the ATF temperature.
(8) Start the engine.
(9) Slowly move the shift lever from P to D, then move the shift lever to P. Keep the shift lever in each position for approximately 3 seconds.
(10) While observing the D shift indicator on the combination meter, move the shift lever back and forth between N and D at an interval of less than 1.5 seconds for 6 seconds or more. Do not pause for more than 1.5 seconds. Performing this operation will cause the vehicle to enter automatic transmission fluid temperature detection mode.
(11) Check that the D shift indicator turns off for 2 seconds.
(12) Move the shift lever from N to P.
(13) Release the brake pedal.
(14) Select the Active Test item: Connect the TC and TE1 / OFF.

It's a way to program the vehicle's computer to enter a type of DIAGNOSTIC/MAINTENANCE MODE. Moving the shift lever from N to D rapidly selects FLUID TEMPERATURE DETECTION MODE.

Without first "conneting the TC to TE1," the vehicles's computer will have no way of knowing why you are moving the shift lever rapidly from one position to the other (i.e., Are you just shifing from one gear to another, or are you wanting to perform a special maintenance function.).

As you already know, engine RPMs are not constant during idle, which in turn affect the speed/rotation of the internal components in the transmission.

The main benefit of putting the vehicle in FLUID TEMPERATURE DETECTION MODE is that the vehicle's computer will command the engine RPMs to be at constant. This in turn will cause the internal components in the transmission to also move/rotate at a constant speed.

Having the internal components of the transmission moving at a constant speed allows for the absolute best accuracy when adjusting the ATF fluid level.

NOTICE: Make sure that terminals TC and TE1 are not connected. If the terminals are connected, the automatic transmission fluid level cannot be precisely adjusted due to fluctuations in engine speed. Even after terminals TC and TE1 are disconnected, automatic transmission fluid temperature detection mode will be active until the engine switch is turned off.

 

[Sajan]

want to share my experience with the DIY. thanks @Artie for the helpful tips via DM.

About a 1000 miles ago, I gave 4qts of ATF to a local mechanic (TEQ solutions/jeboost) to have it done "professionally" since I didn't want to screw it up. I also outsourced coolant, brake fluid and AHC fluid. Coolant, brake fluid and AHC was overfilled.
But I had no way of verifying the ATF without doing it myself..I noticed the shifts were a bit more "pronounced" even in normal mode....felt like something was off.

Bought 12 qts of ATF and decided to 3 drain/fills.

drained 3qts, refilled 3..cycled it

drained 3.25, refilled 3.25, cycled it..

drained 3, refilled 3, plus an extra half a quart for fluid adjustment.

fluid adjustment:
connected tech stream, set the TC and TE1 to ON.
turned car on and cycled from P to D
then moved shift from N to P back and quickly till D light turns off.
set the TC and TE1 OFF.

monitored AT temp 1. mine started at 98F because car is in the garage in hell. Once it got to 104 F i opened the plug and let it drain till it got to a trickle/drip drip..
i got scared because a lot came out and i was worried the temp would go over 115...but luckily by 108F it was trickling.

I closed the drain plug and turned the car off

now here's the crazy part, i got one full quart out during the fluid adjustment....huh..that seems like a lot??
was my AT overfilled by the mechanic? my guess is....yes.

Drove the car for a few miles and shifts felt great. Barely noticed them.

 

[Sajan]

here are the torque specs for a 2018 LX 570 that I used.
Oil pan tube, I barely hand tightened it. Doubt anyone even has something that goes to 7inch lbs.
The transmission case cover, it's tough to get a torque wrench on the top 2 bolts so I just snugged them down.

Using a 5 mm hexagon socket wrench, install the transmission oil pan tube to the automatic transmission assembly.
Torque: 7 in·lbf

Using a 5 mm hexagon socket wrench, install a new gasket and the overflow plug to the automatic transmission assembly.
Torque: 12 ft·lbf

Install a new O-ring and the refill plug to the automatic transmission assembly.
Torque: 29 ft·lbf

Install the transmission case cover with the 3 bolts.
Torque: 9 ft·lbf

Install the oil pan protector with the 4 bolts.
Torque: 37 ft·lbf

 

[FrazzledHunter]

So I have a local shop scheduled to do the 3 fill and temp adjust procedure.
I talked to the mechanic about the procedure and he claimed familiarity with the process, the blue snorkel tube, bringing to temperature etc...
He will be using Toyota ATF, gaskets and O rings.
We didn't discuss "temperature detection mode".

From the previous post it says that the engine is maintained at a constant speed and that the fluid height is affected by the movement of the transmission internals.

Question: anyone have an opinion on how critical is this? The main point of the drain at a certain temperature, AFAIK, is to make sure that the fluid is at a temperature where the volume of the fluid will result in correct height for draining with the blue snorkel tube in place.

Question: what is the engine RPM when it's in "temperature detection mode"?

 

[gasman4u]

So I have a local shop scheduled to do the 3 fill and temp adjust procedure.
I talked to the mechanic about the procedure and he claimed familiarity with the process, the blue snorkel tube, bringing to temperature etc...
He will be using Toyota ATF, gaskets and O rings.
We didn't discuss "temperature detection mode".

From the previous post it says that the engine is maintained at a constant speed and that the fluid height is affected by the movement of the transmission internals.

Question: anyone have an opinion on how critical is this? The main point of the drain at a certain temperature, AFAIK, is to make sure that the fluid is at a temperature where the volume of the fluid will result in correct height for draining with the blue snorkel tube in place.

Question: what is the engine RPM when it's in "temperature detection mode"?

I THINK the engine is at idle when all of this is occurring. It doesn’t increase RPM’s to “fast idle” (think winching application) when I’ve done it. Don’t forget the fluid volume expands with increased temperature too, so it’s not all about the fluid coating the plates, etc. I believe the temp aspect is more important here vs the engine RPM’s.

 

[Sajan]

I THINK the engine is at idle when all of this is occurring. It doesn’t increase RPM’s to “fast idle” (think winching application) when I’ve done it. Don’t forget the fluid volume expands with increased temperature too, so it’s not all about the fluid coating the plates, etc. I believe the temp aspect is more important here vs the engine RPM’s.

The RPMs shouldn't fluctuate that much if you don't have any load on it, like AC, lights, audio, fans etc.

But! When I first turned the car on, idle was higher as part of initial start...and when I put it in temp detection mode, it immediately went down to the normal idle rpm (i totally forgot to look at what exact value was...i can go back and see..).
to my ears it sound exactly the same the whole time I was doing the fluid level check. so it does keep it steady. my guess is 650-750.

I saw a video where someone was doing this, the fluid was dripping at a steady rate and suddenly the RPM kicked up and the fluid level stopped...my guess is he forgot to turn off the AC or something.

You don't need tech stream to do this.
You can set jump the OBD2 pins, do the same N to D shift patterns, then use an app to monitor the AT1 temp.

 

[04UZJ100]

So I have a local shop scheduled to do the 3 fill and temp adjust procedure.
I talked to the mechanic about the procedure and he claimed familiarity with the process, the blue snorkel tube, bringing to temperature etc...
He will be using Toyota ATF, gaskets and O rings.
We didn't discuss "temperature detection mode".

From the previous post it says that the engine is maintained at a constant speed and that the fluid height is affected by the movement of the transmission internals.

Question: anyone have an opinion on how critical is this? The main point of the drain at a certain temperature, AFAIK, is to make sure that the fluid is at a temperature where the volume of the fluid will result in correct height for draining with the blue snorkel tube in place.

Question: what is the engine RPM when it's in "temperature detection mode"?

Idle.

 

[paulunm]

I'm confused- I thought you EITHER had to do the temp detection mode (jump OBD pins, moving from N to D) OR you could use an app to determine when you're at the correct temp to pull the fluid level plug?

Is that not correct- and you have to do the OBD pin, N to D procedure AND monitor transmission temp?

 

[Sajan]

I'm confused- I thought you EITHER had to do the temp detection mode (jump OBD pins, moving from N to D) OR you could use an app to determine when you're at the correct temp to pull the fluid level plug?

Is that not correct- and you have to do the OBD pin, N to D procedure AND monitor transmission temp?

I was confused also but this is my understanding of it now.

There are two parts to this.
1. Putting the car into fluid temp mode to keep RPM steady
Prior to doing N to D to N movements..you need to either
a. use techstream to Connect the TC and TE1
b. jump pins on the OBD2 port
one of those is a prereq for you to do the N to D to N movements.
once the D light turns off, you either set TC TE1 to OFF or remove the pin.

2. Monitoring ATF temp.
This is as simple as using an app or techstream to monitor ATF temp. 102-115 F is the range you are looking for.
Monitoring temp does not require step one.

 

[paulunm]

Interesting, anyone else do both?

I monitored trans temp then pulled the overflow- RPM was steady/AC was not cycling. The truck sure shifts great having used that sole method.

 

[GrouchyTech]

If you’re within the temperature range, engine at idle, parked on level ground, the level you set will be OK.

 

[paulunm]

If you’re within the temperature range, engine at idle, parked on level ground, the level you set will be OK.

I was hoping the expert would chime in! I even used a bubble level

Thank you

 

[FrazzledHunter]

If you’re within the temperature range, engine at idle, parked on level ground, the level you set will be OK.

Thanks for this as it is what I concluded after searching for published documentation that says what this "temperature monitoring mode" does.

I'm still paranoid over the process, however.
I think once I get my truck back from the mechanic and cold, add 1/2 quart ATF, start and bring to temperature as measured by my OBDlink and open the bottom drain bolt and see what happens. I have the gaskets and O rings.
With the ATF just changed, the fill & drain bolts will certainly be removable. That is unless they were over tightened and assuming the mechanic actually did ANYTHING.