Fixing the Hybrid First 1–2 Shift

[CAMTuning]

One behavior I have continued to work on with the hybrid Tacoma and 4Runner is the hard first 1–2 shift after the vehicle has been sitting.

Owners describe it in different ways: a jolt, thump, surge, or unusually firm shift. The common pattern is that it happens on the first drive of the day, then the transmission shifts normally afterward.

I have been working on this for a while with several customers, testing different approaches and comparing their feedback with the calibration data.

After a lot of testing, I was able to isolate what was causing the behavior and make a targeted correction without changing the way the transmission behaves the rest of the time.

The result is a much smoother first 1–2 shift.

This is one of the reasons I continue developing these calibrations long after the initial tune is released.

As I learn more about how these vehicles behave in different situations, I continue refining what my customers receive.

A big part of that is made possible by customers who are willing to test changes, report back honestly, and help me isolate behaviors that are difficult to reproduce on one vehicle alone. That real-world feedback is extremely valuable and directly improves the calibration for everyone.

Any existing CAMTuning customer with a hybrid Tacoma or 4Runner who experiences the hard first 1–2 shift can reach out for a free updated calibration.

This change is also being incorporated into all future hybrid calibrations.

Sponsored

 

[MikeD]

One behavior I have continued to work on with the hybrid Tacoma and 4Runner is the hard first 1–2 shift after the vehicle has been sitting.

After a lot of testing, I was able to isolate what was causing the behavior and make a targeted correction without changing the way the transmission behaves the rest of the time.

The result is a much smoother first 1–2 shift.

So… can you explain “what was causing the behavior”?

 

[CAMTuning]

So… can you explain “what was causing the behavior”?

I can, but not without revealing enough to give other tuners what they need to duplicate it. It is primarily torque converter behavior though.
Is your 4Runner one that suffers from it?

 

[TheMountain74]

Mine suffers from it too. So is it not every hybrid vehicle? I just started realizing it's during my first drive, I thought i was stepping on the gas incorrectly, causing it to jolt.

 

[CAMTuning]

Mine suffers from it too. So is it not every hybrid vehicle? I just started realizing it's during my first drive, I thought i was stepping on the gas incorrectly, causing it to jolt.

It may be all of them, but maybe not everyone is bothered by it enough to mention it. I’ve read countless accounts of it on the forums and social media.

 

[pmedicj]

It is the first shift of the day after sitting.
So it’s software issue then? Also, is it damaging anything the way it is and or is there a purpose for Toyota programming it this way or just an oversight on their part?

 

[MikeD]

I can, but not without revealing enough to give other tuners what they need to duplicate it. It is primarily torque converter behavior though.
Is your 4Runner one that suffers from it?

Fair enough, Cam.

I guess I've noticed the issue but its very subtle on my TRD ORP hybrid and it never bothered me.
I had the OTT tune done about a year ago and also find the improvement to be somewhat subtle (as compared to others who rave). I'm not sure if it had any impact on the very subtle clunk in low gear transitions. I guess my "butt dyno" is just not as sensitive as some. I've always been more than happy with the performance of the vehicle.

I thought I'd ask about the cause because I have found your posts on tuning to be very enlightening and educational (I'm a curious engineer but not one with any background in automotive or any kind of engine/transmission engineering.) Your answer, though brief, is still helpful.

Keep the education coming.

Thanks

 

[TheMountain74]

It may be all of them, but maybe not everyone is bothered by it enough to mention it. I’ve read countless accounts of it on the forums and social media.

Thanks, I noticed it the first time, but thought I just accelerated unproperly, but then caught it a few other times after that, and started to think it was weird. Glad to know it's a known thing. Of course I try and warm my car up 95% of the time. But sometimes I just need to start and go.

 

[CAMTuning]

It is the first shift of the day after sitting.
So it’s software issue then? Also, is it damaging anything the way it is and or is there a purpose for Toyota programming it this way or just an oversight on their part?

It does appear to be calibration related. Toyota handles some things differently immediately after startup, and I’ve identified a change that so far seems to improve that first-shift of the day (or long sit) behavior.

I can’t say whether Toyota had a specific reason for programming it that way or if it’s simply an unintended drivability characteristic. I also haven’t seen anything suggesting it’s causing damage.

The benefits of tuning don’t always have to be about adding power. If I can identify things like this and improve the way the truck behaves in everyday driving, that’s added value for my customers too.

 

[MTN Dew]

So I am experiencing this hard shift, how do I get this calibration?

 

[CAMTuning]

Fair enough, Cam.

I guess I've noticed the issue but its very subtle on my TRD ORP hybrid and it never bothered me.
I had the OTT tune done about a year ago and also find the improvement to be somewhat subtle (as compared to others who rave). I'm not sure if it had any impact on the very subtle clunk in low gear transitions. I guess my "butt dyno" is just not as sensitive as some. I've always been more than happy with the performance of the vehicle.

I thought I'd ask about the cause because I have found your posts on tuning to be very enlightening and educational (I'm a curious engineer but not one with any background in automotive or any kind of engine/transmission engineering.) Your answer, though brief, is still helpful.

Keep the education coming.

Thanks

I appreciate that. I’m really just a curious mechanical engineer who got into tuning almost by accident about 20 years ago, and somehow that turned into this. A lot of what I enjoy about it is exactly what you’re describing—trying to understand why something behaves the way it does, then figuring out whether it can be improved.

I can appreciate a skeptical butt dyno. If something is genuinely better, you shouldn’t have to talk yourself into feeling it.

If you ever get curious enough to compare approaches, I’d be happy to tune it on the COBB platform and let you judge the difference for yourself. Then you can decide whether your butt dyno is really that insensitive, or whether what you’ve been feeling so far has just been subtle.

 

[CAMTuning]

So I am experiencing this hard shift, how do I get this calibration?

You’d need the COBB Accessport and one of my tuning options here:

Accessport + Tune at CAMTuning

I'm currently matching Cobb's 10% off on their Accessports, and the discount is reflected in the cart.
If you already own an Accessport, I have options for that.

For a stock or lightly modified hybrid, the Reflash is perfectly fine for this. It uses my developed calibration for your vehicle and will include the first-shift changes I’ve been testing successfully.
The Reflash also includes an in-depth datalog review after installation so I can verify that the vehicle is operating as expected on the calibration.

The Custom Tune takes that a step further with individual revisions based on your vehicle and its data, so that’s the better choice if you have more modifications or want the calibration refined specifically around your setup.

But you do not need to go Custom just to address this issue. The Reflash will include the updated first-shift calibration, along with the datalog review to make sure everything is behaving the way it should.

 

[ThatSickRIp]

The gassers do it too, not just the hybrids.

Also, the LCs do the same thing as well.

 

[CAMTuning]

The gassers do it too, not just the hybrids.

Also, the LCs do the same thing as well.

I’ve had 2 of my non hybrid customers reach out today saying the same thing. I am testing similar logic on their tunes now.

 

[ThatSickRIp]

I’ve had 2 of my non hybrid customers reach out today saying the same thing. I am testing similar logic on their tunes now.

Nice
Are you working with the LCs too? Or just 4Rs and Tacomas?

Sponsored