One behavior that has come up repeatedly on the hybrid Tacoma and 4Runner is a firm or harsh 1–2 shift on the first drive of the day.
Owners describe it in a few different ways. Some call it a jolt or thump. Others describe a surge or lunge forward. The defining characteristic is usually the same: it happens during the first 1–2 shift after the vehicle has been sitting, then the transmission behaves normally afterward.
This has been something I have been actively working on with several CAMTuning customers.
Identifying the Cause
The challenge with this behavior is that it is very specific to that first drive after the vehicle has been sitting.
That makes it harder to reproduce consistently and harder to isolate than a shift issue that occurs all the time.
Through continued testing, datalog review, and customer feedback, I was able to narrow the issue down and make a targeted calibration change specifically for this operating condition.
The result is a much smoother first 1–2 shift without changing the normal transmission behavior once the vehicle is underway.
Why Continued Development Matters
This is a good example of why I continue developing calibrations even after a platform has been supported for some time.
The more vehicles I tune, the more unusual operating conditions and edge cases I get to see.
Some behaviors are easy to reproduce on my own development vehicles. Others may only show up under a very specific set of conditions.
That is where customer feedback becomes incredibly valuable.
I have several customers who have been willing to test experimental changes, drive them in the exact conditions where the problem occurs, and report back with detailed feedback.
That allows me to isolate a problem, verify the result, and then incorporate what I learn into the calibration for everyone else.
My customers are a major part of why these calibrations continue to improve.
Existing Hybrid Customers
Any existing CAMTuning customer with a hybrid Tacoma or 4Runner who experiences the hard first 1–2 shift can contact me for a free updated calibration.
This correction is also being added to all future CAMTuning hybrid calibrations.
Development does not stop when a tune is released. As I continue learning more about these platforms, those improvements continue making their way back to the people already running my calibrations.