Testing R-D Delay (Plus P-D Delay)

Im running a test.....

When I start the truck up cold, I slightly rev the engine once (just a little) in neutral, THEN put it in Drive. So far, when using this technique I have not had any delay dropping into drive (which otherwise is a daily occurrence). Next step is to try this out before engaging reverse to see if it eliminates the R-D delay.

Clearly the delay is not caused by low fluid. And I doubt it is electronic (i.e. a transmission "update" isn't going to resolve anything....

So maybe the tranny hydraulic pump doesn't provide enough pressure when cold to engage D quickly. Wonder how they will fix that? Auto-rev? LOL

Post up if it works for you. Everyone is so relieved to have <1 q of fluid topped off, but nobody seems to care that topping off resolves nothing.

 

I see most folks claim it was fixed after topping off with fluid but agree have seen a handful who honestly report no difference. Yes 1 quart of fluid can make a difference and can be harmful to a transmission -- that point has been proven. But why the inconsistency in feedback? I'm thinking those who think it was fixed are experiencing some placebo affect and the actual root cause for erratic transmission behavior is not completely attributed to low fluid.

 

How long is the delay? My old truck (ford) was an automatic and always had a slight delay and clunk sound (even with new ujoints) when shifting from reverse to drive.

Well, then again, that transmission ended up shitting itself at 140k miles. I had to spend the first couple of minutes of cold mornings stuck in 1st gear lol, sure don't miss that.

 

Topping off with fluid made ZERO difference in my truck. I was a qt. low from the factory. I've learned to live with it until Toyota figures out the issue. Has to be electronic.

 

I believe it is not LOW fluid related, only because topping off made no difference in my particular case. Others have claimed topping off resolved the delay (including me initially), but not many. Seems that most have seen no improvement at all, but they are extremely relieved that the pan is now full.

I assumed that increasing fluid pressures could only be accomplished mechanically, or by spinning the pump faster (such as in my test simulation). If programming alone can increase the fluid pressure from the pump, then GREAT! I hope you are right!

 

More speculation on my part, but in the spirit of gathering facts....

On older transmissions, it's pretty easy to hook up a pressure gauge to measure the fluid pressure in each gear. You could even observe a delay in pressure rise (if it exists) to confirm the existence of the issue (though not necessarily the cause). Between all of us, couldn't we determine if the Gen 3 trans has an available pressure port, and if we could use it for any useful purpose? I hate the thought of just "waiting for an update."

TRDinOhio is right....Toyota is not the first manufacturer to have this issue. Look here http://www.bimmerfest.com/forums/archive/index.php/t-490057.html

Those guys got f#cked because BMW decided it was "normal" and not an issue since drivers become accustomed to the delay. Sound familiar?

 

It might be a long shot but after reading a lot of these threads does anyone know if the new transmissions pump fluid while in park?
Some other trucks did not and this sounds like a similar symptom. Converter draining and when initially cranked it doesn't pump up till neutral or drive is engaged.

 

Hey guys .
Yes these transmissions charge the converter with oil in park and Park is where your oil needs to be checked with the engine running .
SYMPTOMS OF LOW ON FLUID
slow to go in gear on cold start ".
slips when turning corners "
slips while going uphill .
falling into neutral
long delay from reverse to drive
shifting vibrations and downshift clunking .
converter chatter
shift busyness from 4th through to 6th gear
Some members are not feeling any symptoms and finding out their fluid is low
Come to a complete stop before selecting forward or reverse . This is driving 101


Next ...after the fluid level has been " CONFIRMED " as full and you continue to feel a delay from Reverse to drive

STILL HAVING DELAYS AFTER PROPER FLUID TOP OFF ( 5/4/2016 )
Some members are taking their trucks to the dealership to have the fluid level topped off properly and are still experiencing a delay from reverse to drive . Toyota uses " SQUAWK " control to prevent that initial lurching feeling when the transmission shifts into forward .
Squawk control selects 2nd gear rather than first gear to remove that lurching feeling . Squawk control is computer controlled and the logic can easily be re-written to improve this. Expect six months to a year for a fix .
Toyota needs documentation of your issue in order to fix this . If they dont get the complaints and a track record of the problem , they are going to say its normal and make you live with it .
It is why I have been begging you guys to call corporate and create a case number when you bring your truck in to the dealer .
Its all in the low fluid poll here https://www.tacomaworld.com/threads...be-low-on-fluid-directly-from-factory.405642/

 

Got my 5k coming up. Although my 0.8 Q low is on the record, I will definitely get the continuing delay on the books before the "checkup."

 

Interesting, that the acceptable delay is 1.2-1.5 seconds even after warmup.

 

Thats about the norm for all automatic transmissions . As transmissions become newer and more sophisticated/complex , the delay can become longer .
We are familiar with older automatics that used mechanical inputs to change directions .
As transmissions become newer , solenoids and computer inputs are utilized such as Toyotas SQUAWK control that make the initial inputs take longer to apply the C1 clutch .
Selecting Neutral bypasses the Squawk control feature and allows for a quicker application .
In Neutral , the computer control is bypassed , therefore when you select forward movement from the neutral position , the transmission immediately selects 1st gear forward rather than the smooth 2nd gear with squawk control .
Hope this makes sense

 

I get the delay whether going from R to D, or from P to D. Both of those combinations pass through N to get there. Interestingly, I NEVER get a delay from P-R, which based on what you are saying, should take longer to receive and act on the inputs.

I'll try a few times shifting into neutral for a few seconds before selecting a forward gear to see if bypasing SQUAWK eliminates the delay.

 

Thats the issue you guys are having problems with . The initial delay from reverse to drive on a cold start .
As mentioned above by other members , we need a truck that has the level of the fluid " confirmed as full " .
We need a pressure gauge connected to verify proper hydraulic pressure .
We need a Techstream scanner connected to monitor parameters as we shift through the gear ranges .
Passing through Neutral will not get you results . You need to select Neutral and idle in the neutral position to bypass Squawk control.
I highly doubt any Toyota dealership will go this far in diagnostics and we have yet to hear from a third party transmission shop as to the actual cause of the delay with a properly filled transmission .
Could it be a pressure issue with the hydraulic system on cold start ..yes
Could it be a drain back problem allowing the torque converter to lose its charge of fluid after a couple hours ....yes
Could it be a computer control issue on cold start up with solenoids ,programming/coding , force motors , pressure transducers ....highly likely .

When your transmission is in Park , it will anticipate your next move by applying a solenoid controlled clutch . This reduces the time it takes to apply 2 individual clutches .
When your transmission is in reverse , it will also anticipate your next move by applying a solenoid controlled clutch .
The two mentioned above are controlled by the computer in your truck .

What we know so far according to the poll . 182 trucks were low on fluid
95% of the 2016 trucks that had a low fluid problem no longer have complaints of delays
5% of the 2016 trucks that had a low fluid problem still have a delay only from reverse to drive .
Of those 5% , it is still unclear that they were properly topped off with trans fluid or were taken to a third party transmission shop to confirm the delay .
Your dealerships are going through a large learning curve as these trucks come into the shop and need fluid .
Many of the dealerships knew little on how to properly fill these transmissions even though they have been out since 2005
Was the adaptive learning completely cleared on all the trucks ? I didnt ask this in the poll .

All I can suggest is to continue testing as you have planned

 

How much would one expect to pay for a full evaluatipn from a transmission shop?

 

The trans shop would need to be completely informed of the issue at hand .
The trans shop would need the latest Toyota software installed on their scanners and up to date repair info installed on their data base . Aftermarket is always 1 year behind in most cases . It cost me $4500 last year in order to update my technical information to 2015 . This is just the information , no training for the technicians .

With this said , we would need a donor truck that had low fluid and was " Corrected ' to full at the dealership .
The transmission is new , the technology is old .
As far as diagnostic time , I would gather about 6 hours .
Of the 6 hours , some of this would be forgiving for third party as it would be experimental .
Things a transmission shop cant do ? Toyota coding .

It is why Toyota needs to fix this at the engineering level rather than the aftermarket

 

Confirming today that tapping the gas prior to shifting out of Park totally eliminates the delay. Makes me hopeful that some kind of simple update can resolve this.

 

Did it idle any differently or sound different when you shifted through neutral?

 

Nope. Just bumped the throttle, then shifted into Drive afterwards. Behaved "normally" (with "normal" meaning like every other car ever produced in the history of mankind, not 3rd Gen Tacoma "normal").

 

This dude knows his stuff!!!! Glad we have guys like this and @TRDinOhio to weigh in on issues. Experienced professionals.