Toyota Heater Switches Learn New Tricks

July 5, 2024 by Tom Nardi 32 Comments

The look, the feel, the sound — there are few things more satisfying in this world than a nice switch. If you’re putting together a device that you plan on using frequently, outfitting it with high-quality switches is one of those things that’s worth the extra cost and effort.

So we understand completely why [STR-Alorman] went to such great lengths to get the aftermarket seat heaters he purchased working with the gorgeous switches Toyota used in the 2006 4Runner. That might not sound like the kind of thing that would involve reverse engineering hardware, creating a custom PCB, or writing a bit of code to tie it all together. But of course, when working on even a halfway modern automobile, it seems nothing is ever easy.

The process started with opening up the original Toyota switches and figuring out how they work. The six-pin units have a lot going on internally, with a toggle, a rheostat, and multiple lights packed into each one. Toyota has some pretty good documentation, but it still took some practical testing to distill it down into something a bit more manageable. The resulting KiCad symbol for the switch helps explain what’s happening inside, and [STR-Alorman] has provided a chart that attributes each detent on the knob with the measured resistance.

But understanding how the switches worked was only half the battle. The aftermarket seat heaters were only designed to work with simple toggles, so [STR-Alorman] had to develop a controller that could interface with the Toyota switches and convince the heaters to produce the desired result. The custom PCB hosts a Teensy 3.2 that reads the information from both the left and right seat switches, and uses that to control a pair of beefy MOSFETs. An interesting note here is the use of very slow pulse-width modulation (PWM) used to flip the state of the MOSFET due to the thermal inertia of the heater modules.

We love the effort [STR-Alorman] put into documenting this project, going as far as providing the Toyota part numbers for the switches and the appropriate center-console panel with the appropriate openings to accept them. It’s an excellent resource if you happen to own a 4Runner from this era, and a fascinating read for the rest of us.

This Time It’s Toyota: Takata Airbag Recalls Continue

February 1, 2024 by Jenny List 22 Comments

The automotive industry is subject to frequent product recalls, as manufacturers correct defects in their vehicles that reveal themselves only after some use. While such events may be embarrassing for a marque, it’s not necessarily a bad thing — after all, we would rather put our trust in a carmaker prepared to own up and fix things rather than sweep their woes under the carpet.

There’s one recall that’s been going on for years which isn’t the vehicle manufacturer’s fault though, and now it seems Toyota are the latest to be hit, with some vehicles as old as two decades being part of it. Long time Hackaday readers will probably recognize where this is going as we’ve covered it before; at its centre are faulty airbag charges from Takata, and the result has been one of the largest safety related recalls in automotive history.

An automotive airbag is a fabric structure inflated at high speed by a small explosive charge when triggered by the sharp deceleration of an incident. It is intended to cushion any impact the occupant might make upon the car’s interior. The problem with the faulty Takata units is that moisture ingress could alter the properties of the charge, and this along with corrosion could increase its power and produce a hail of metal fragments on detonation.

Our colleague [Lewin Day] has penned a series of informative and insightful investigations of the technology behind the Takata scandal, going back quite a few years. With such relatively ancient vehicles now being recalled we can’t help wondering whether it would be easier for Toyota to run a buyback scheme and take the cars off the road rather than fix them in this case, but we’re curious as non automotive safety engineers why the automotive airbag has evolved in this manner. Why is one of very few consumer explosive devices not better regulated, why is it sold with an unlimited lifetime, and why are they not standardized for routine replacement on a regular schedule just like any other vehicle consumable?

2003-2004 Toyota Corolla: IFCAR, Public domain.

Toyota Makes Grand Promises On Battery Tech

July 10, 2023 by Bryan Cockfield 125 Comments

Toyota is going through a bit of a Kodak moment right now, being that like the film giant they absolutely blundered the adoption of a revolutionary technology. In Kodak’s case it was the adoption of the digital camera which they nearly completely ignored; Toyota is now becoming similarly infamous for refusing to take part in the electric car boom, instead placing all of their faith in hybrid drivetrains and hydrogen fuel cell technologies. Whether or not Toyota can wake up in time to avoid a complete Kodak-style collapse remains to be seen, but they have been making some amazing claims about battery technology that is at least raising some eyebrows. Continue reading “Toyota Makes Grand Promises On Battery Tech” →

Hackaday Links: February 5, 2023

February 5, 2023 by Dan Maloney 33 Comments

Well, this week’s Links article is likely to prove a bit on the spicy side, thanks in no small part to the Chinese balloon that spent the better part of the week meandering across the United States. Putting aside the politics of the whole thing — which we’ll admit is hard to do, given the state of the world today — there are some interesting technical aspects to this story, which the popular press has predictably ignored. Like the size of this thing — it’s enormous. This is not even remotely on the same scale as the hundreds of radiosonde-carrying balloons sent aloft every day, at least if the back-of-the-envelope math thoughtfully sent to us by [Dr_T] holds up. If the “the size of three buses” description given in most media reports is accurate, that means a diameter of about 40 meters, for a volume of 33,500 cubic meters. If it’s filled with helium — a pretty safe bet — that makes its lifting capacity something like three metric tons. So maybe it was a good idea to wait until it was off the Carolinas to shoot it down.

Continue reading “Hackaday Links: February 5, 2023” →

Recreating The “Stuck Throttle” Problem On A Toyota

October 30, 2022 by Bryan Cockfield 68 Comments

A few years ago, Toyota was in the news for a major safety issue with a number of their passenger vehicles. Seemingly at random, certain cars were accelerating without concern for driver input, causing many crashes and at least 37 confirmed deaths. They issued recalls both for the floor mats which were reported to have slid forward to jam the accelerator pedal, but this didn’t explain all of these crashes. There was another recall for stuck throttles, which [Colin O’Flynn] demonstrates a possible cause for on his test bench.

While most passenger vehicles older than about 15-20 years controlled the throttle with a cable connected directly from the throttle body to the accelerator pedal, most manufacturers have switched to a fly-by-wire system which takes sensor input from the accelerator pedal and sends that position information to the vehicle’s computer which in turn adjusts the throttle position. This might be slightly cheaper to manufacture, but introduces a much larger number of failure modes to a critical system. Continue reading “Recreating The “Stuck Throttle” Problem On A Toyota” →

The State Of Play In Solid State Batteries

April 27, 2022 by Lewin Day 141 Comments

Electric vehicles are slowly but surely snatching market share from their combustion-engined forbearers. However, range and charging speed remain major sticking points for customers, and are a prime selling point for any modern EV. Battery technology is front and center when it comes to improving these numbers.

Solid-state batteries could mark a step-change in performance in these areas, and the race to get them to market is starting to heat up. Let’s take a look at the current state of play.

Continue reading “The State Of Play In Solid State Batteries” →

New Cars Will Nickel-and-Dime You – It’s Automotive As A Service

December 30, 2021 by Lewin Day 230 Comments

Every few years, someone pushing a startup to investors comes up with an acronym or buzzword which rapidly becomes the new hotness in those circles. One of the most pernicious is “as a Service,” which takes regular things and finds a way to charge you a regular fee to use them.

Automotive companies just absolutely loved the sound of this, and the industry is rapidly moving to implement subscription services across the board. Even if there’s hardware in your car for a given feature, you might find you now need to pay a monthly fee to use it. Let’s explore how this came about, and talk about which cars are affected. You might be surprised to find yours already on the list.
Continue reading “New Cars Will Nickel-and-Dime You – It’s Automotive As A Service” →