Transmission hesitant to downshift at low speeds (2019 CX-9)

[TimGinNJ]

Hi Gang-
I've scoured this forum as well as the interwebs, figuring this had to be something someone else has come across, but apparently not...

2019 CX-9 AWD Siggy - 47K miles:

In normal automatic shift mode (not in Sport or Manual mode), when coming to a stoplight or stop sign, I've noticed that if I do not come to a dead stop, then try to accelerate again, instead of downshifting to 1st, my transmission remains in 2nd or sometimes even 3rd gear and just keeps slipping the torque converter until I'm up to speed. Happened tonight when I was coming to an intersection with a red light; I was coasting up to the light when it turned green...I was probably doing maybe 2 MPH...and when I went to accelerate, my transmission remained in 3rd gear and wouldn't downshift automatically.

As a general rule, I realize these transmissions are programmed to keep the RPMs down to help conserve fuel, but after decelerating to 2-3 MPH and having your trans remain in 3rd gear and refuse to downshift unless I either manually drop it into 2nd or put in Sport Mode doesn't sound right to me. (And no, I won't address this issue by putting it in Sport Mode all the time - lol)

The trans shifts flawlessly in all other situations and at all speeds. No noises, vibrations, or other performance issues. This is literally the only complaint I have about this vehicle.

• Anyone else experience this or have any thoughts on what this might be?
• Is it worth having a trans service (fluid + filter) done?
• Is there some other way to wipe the transmission control unit's adaptive settings and let it "re-learn" the shift points based on my driving...like pulling the battery lead for 12 hours, etc.?

TIA,
Tim G.

 

[Silly Wabbit]

Do a drain and refill and also relearn procedure

Mazda Skyactiv AT initial learning mode. #skyactiv #mazda #automatictransmission

This is a quick video to show how to put a Mazda Skyactiv transmission into initialization mode. This clears all the shift adapts and learned clutch values. ...

youtu.be

 

[Z31]

Is this something that happens all the time in day to day traffic? Or is it a specific scenario that you notice? Maybe try more/less throttle input to experiment?

I know the transmission is doing a lot of things at low speeds. Torque Converter clutches start releasing at 5mph, then has to downshift into 1, and also try to reengage when accelerating after 5mph, so maybe you're just catching it in a funny part of a cycle?

I have a four way stop leaving work thats on a slight uphill grade, and if I do a rolling stop it always does a funny clunk when it gets caught in between 2-1 downshift. No where else ever in driving I feel it, but almost every time in this specific scenario.

Overall I find the low-speed transmission tuning to be one of the best cars I've ever had. Near flawless. Previous to this I had an 8spd Toyota, it would constantly get caught in the deadzone on 2-1 downshift, and leave you with a huge pause, then a big transmission clunk. Great on the open road, but around town it was maddening.

 

[TimGinNJ]

Do a drain and refill and also relearn procedure

Mazda Skyactiv AT initial learning mode. #skyactiv #mazda #automatictransmission

This is a quick video to show how to put a Mazda Skyactiv transmission into initialization mode. This clears all the shift adapts and learned clutch values. ...

youtu.be

Thanks SW. The instructions were pretty straight forward, but for some reason, they don't appear to have worked on my car. I went through the process 3 different times and don't feel as though my car ever entered the diagnostic mode depicted in the video.

Not sure if the display and what's shown in the video at each step of the process differs from model to model, but my display never looked anything like the video and at no point did I ever feel the idle increase or the transmission engaging/disengaging pumps before returning to normal.

I did make sure my car was at operating temp, and also noted that someone added comments to the video about needing to press the brake pedal very firmly the entire time (which I did). I'm gonna' to go drive my car now to see if I notice any difference in shifting and/or the transmission re-learning my driving style, but I'm not holding my breath.

Thanks,
TimG

 

[sinistriel@]

I made the linked video, if the idle increase did not happen then it did not enter the relearn mode. The steps are the same for all the Skyactivs and sometimes it just takes multiple times to get it to work. The two keys are transmission fluid temp and holding the brake firmly the whole time.

 

[Silly Wabbit]

I made the linked video, if the idle increase did not happen then it did not enter the relearn mode. The steps are the same for all the Skyactivs and sometimes it just takes multiple times to get it to work. The two keys are transmission fluid temp and holding the brake firmly the whole time.

Thanks for making the video!

I couldn't replicate until my 6th attempt. Make sure you put enough pressure on the brake.

 

[TimGinNJ]

I made the linked video, if the idle increase did not happen then it did not enter the relearn mode. The steps are the same for all the Skyactivs and sometimes it just takes multiple times to get it to work. The two keys are transmission fluid temp and holding the brake firmly the whole time.

Thanks for chiming in. I definitely appreciate you putting the time into making the video.

One thing that might have thrown me off; I'm wondering if my CX-9's gauge cluster might not show the same visual queues as your 3 did. I also saw in the comments section some other folks were a little confused at one particular step in the process whether they should be in Manual (+) or Manual (-) and holding vs not holding. I saw you had added a transcript to the comments, so I've printed that out and will be trying again after work.

Thanks again

 

[TimGinNJ]

I made the linked video, if the idle increase did not happen then it did not enter the relearn mode. The steps are the same for all the Skyactivs and sometimes it just takes multiple times to get it to work. The two keys are transmission fluid temp and holding the brake firmly the whole time.

Hey sinistriel- Well, I finally got my CX9 to enter relearning mode.....after maybe 8 attempts? I know this isn't rocket science but for the life of me, I couldn't figure out why it wasn't working....vehicle temp up to normal, brake pedal absolutely mashed, but nuttin;. The last time I tried it, I allowed for more than 5 seconds where called for...and the only thing I can think of that I did differently was also having the emergency brake engaged. No idea if that made a damn bit of difference....or my car was just being stubborn, but either way....it was obvious when it entered re-learning mode--just as you described it. Have a 50 mile commute to work tomorrow which should allow the adaptive values to be relearned...I just hope my car won't be such a diva the next time I try to do this

Thanks again for producing this....you're as community hero!

Cheers,
Tim

 

[sinistriel@]

Hopefully it makes a difference for you, I know a lot of people have seen good results.

 

[acidbug]

The way the engineers from Mazda tune the throttle pedal soft. Has to do with the EPA, etc. Follow the instructions as listed above to relearn the throttle pedal and also do at least two tanks of 93 and if 93 octane isn’t available go for 91 hopefully this will address the issue