It’s common for the Lexus transmissions to ‘hang’ unto the third gear when cold during normal driving conditions. For many inexperienced users, this appears to be a malfunction. It’s not and today, I explain why.
Remember the cold, chilly mornings when you crank your vehicle and hit the freeway only to be met with a reluctant tranny that won’t simply engage past the third gear no matter how much gas you give the accelerator?
It turns out this is perfectly normal and isn’t something you need to worry about. That is how modern transmissions are designed.
But, do not take my word for it: here’s the explanation:
Table of Contents
Why Your Auto Transmission Doesn’t Shift Past Third Gear When Cold
The reasons for the sluggish shifting of a tranny when cold are numerous and varied. However, here are the most notorious.
1. Fluid Viscosity
Transmission fluid is meant to lubricate and provide ‘hydraulic value’ to the numerous subsystems of modern auto transmissions.
Unfortunately, when cold, this fluid gets thicker than its normal flow viscosity and usually flows slower.
With thicker fluid that doesn’t power through as quickly as it ought to, the system, through the ECU, naturally limits the number of gears the transmission can cycle through in this state.
We all know that the third gear is the sweet spot; it’s powerful enough to keep you going but also slow enough to perform torquey demands when occasion calls.
2. Emission Control and Fuel Efficiency
The craze for ‘saving the earth’ and improving fuel efficiency only gets tougher—and currently, the day’s discussion is which auto manufacturer will be the last to ditch the V8.
For perspective, Toyota, an ultra-conservative company has ditched the V8 engine in its trucks and SUVs, opting instead for a turbo-charged V6 and hybrid options.
For sedans like the Camry, 2024 offers the last year these little bulletproof pieces will come with a V6 offering.
The handwriting is already on the wall: auto manufacturers are interested in getting the most EPA rating they can for the class while also causing the least pollution possible, for the class.
This is where programming the ECU to restrict the gears possible when an engine and tranny are cold makes a lot of sense: with this restriction, you’d be forced to drive gently when your vehicle is in open loop.
The results?
Overall better MPGs and less emissions.
3. Tranny Wear and Tear Prevention
Like engine oil, the tranny fluid lubricates the transmission, provides pressure in the system, and importantly, prevents the all-important metal-on-metal contact.
Unfortunately, when the fluid is cold, it doesn’t do this job as great as when it warms up.
What this means is simple: if you decide to drive the vehicle like a maniac when cold – and it allows you, running through the gears normally, there will be more tranny wear and tear at the end of the day than if the vehicle does all it can to limit you to third, while the fluid warms up.
If you’re the type of car owner who doesn’t fancy the mechanic, auto DIY, or changing parts on your vehicle, this point should thoroughly appeal to you.
Wrap Up
If you drive a standard Lexus (or Toyota), great chances are that irrespective of the gears that your vehicle is advertised to have, it will always have a way of hanging around the third gear, from a cold start, changing into a higher gear only when the fluid warms up to operating temperature and everything turns nice and smooth.
If you’ve noticed this, keep calm and focus on your driving…only ensure that you drive gently till the vehicle warms up to operating temperature at which point, you’re free to play with your gas pedal as you wish!