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Automatic Transmission - Toyota

I just purchased a 2012 Toyota Corolla, and am thinking that automatic transmissions have changed since my last car! Do they automatically downshift when going downhill? I notice this especially when I take my foot off the accelerator or press the brake. Also, when driving on level roads, it feels like it doesn’t coast very far when I let off the gas (compared to my old Toyota). Like the engine is pulling back. Any thoughts? Thanks!

Toyotas used to release the torque converter clutch when coasting and now (apparently) they don’t. Why? Don’t know; maybe to reduce wear and tear on that clutch.

The only possible explanation I can think of: does it do this when fully warmed up? Our '07 toyota yaris tends to wind out the gears to higher rpm’s, staying in lower gears even while letting off the gas pedal - but only when cold. Once warmed up it doesnt act this way. It is noted as normal behavior in the owners manual.

The RPMs drop some (not to idle) on my '05 tC when I let my foot off the gas on a descent, and I get some engine braking. It would appear that the torque converter allows a difference between the engine and the drivetrain (which supports insightful’s comment that the TC clutch disengages) and the TC transmits enough of the car’s inertia to allow some engine braking as well. The difference in flywheel and tranny input shaft speeds is I’m sure being converted to heat energy by the torque converter. It doesn’t downshift. I’m thinking that if it did the engine RPMs would jump. Besides, I often downshift that manually and THEN the RPMs jump.

I have no idea what a 2012 Corolla does. Or what it should do.

This is from the U140E AND U241E AUTOMATIC TRANSAXLE part of a 2002 Camry manual but I imagine the newer transmissions have something similar. I know in my moms 2012 Camry you can feel it downshifting as you slow down and at least come out of overdrive if you hit the brakes going downhill. And in my 2002 Camry it will drop out of OD if you hit the brakes going downhill.

Don’t take me wrong but, since this is a new vehicle to you. Do u have the OD canceled by chance? Otherwise, I would have the VSS checked to see it’s correct and shift solenoid checked. VSS staying correct seems to be a problem with older corolla’s. Simple fix.

VSS staying correct seems to be a problem with older corolla's.

2012 is now considered “older” ?

Jeeze, my 2005 must be considered ANCIENT!!!

MAYBE, SOME DO DOWNSHIFT. I can’t say for sure about your Corolla, but my Tacoma definitely does. I initially thought it did only with the cruise control but find it does as I let up on the gas going down hill with out it on as well.
SMB, you mean they made cars back in 2005 ?

LOL, yup! Great ones!

When you let completely off the gas the injectors are shut completely off until you either press the brake or the gas pedal. This is done to increase fuel mileage and reduce emissions.

I think we can safely assume that OP’s transmission is behaving normally . . . ?

Yes it’s normal.

Steve, may I ask where you’re getting this information?

Sounds like Steve might work at a Toyota dealer and really knows his stuff

Db4680 hit the nail on the head, I have worked for Toyota/Lexus since 2002, before that I was with General Motors.

Interesting. I was unaware that the Corolla shut the injectors down and wondered if I should be learning something or questioning something. I’ve learned something.

Thanks for responding. A tip of the hat to you, with the utmost respect.

I think my 2002 Sienna shuts down the injectors going down hill. Going down the 17 mile drop to Orizaba it definitely shuts them off.

I find myself wondering now if my '05 tC shuts its injectors off. Unfortunately, since retiring I no longer have access to Toyota’s technical documents. I don’t miss working, but I really do miss that portal.

mountainbike

You know that you could pay a modest fee to gain access to toyota’s website, for a few days . . . ?

Those fees are actually tax deductible