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.