It can be incredibly frustrating when your car key fob suddenly stops working. Yesterday, I experienced this firsthand with my 2016 Toyota Corolla Key Fob, and what started as a moment of panic turned into a valuable lesson about car key fob batteries.
Initially, when one of my key fobs became unresponsive, my first thought was that something was seriously wrong. I immediately suspected a complex electronic issue. Taking the battery out, a quick check with a voltmeter showed a reading of 2.5v. This was with a generic Chinese battery that came with the replacement key fob I had recently purchased online. My immediate assumption was a faulty battery.
Confident I had a solution, I grabbed one of my “fresh” Panasonic CR2016 batteries. These were purchased online a few years back, but all indicated an expiration date of 12/2022, and each tested at approximately 3.3v with my voltmeter. However, to my surprise, the key fob still refused to work. Removing the “fresh” battery and testing it again, it still displayed a healthy 3.3v. This was puzzling.
Just as I was about to delve into more complicated troubleshooting, my wife was heading to the store. On a whim, I asked her to pick up a brand new CR2016 battery. Skeptical but willing to try anything, I installed the newly purchased Energizer battery. To my astonishment, it worked! Not only that, but all four of my key fobs sprang back to life with the new batteries.
The key takeaway from this experience is simple but crucial: don’t rely solely on a voltage test or expiration date to determine the health of a coin battery for your 2016 Toyota Corolla key fob. Just like larger car batteries, these small coin cell batteries can show good voltage but still fail under load. My “fresh” Panasonic batteries, despite their seemingly good voltage and expiration date, were clearly no longer capable of providing the necessary power to operate the key fob reliably.
So, if your 2016 Toyota Corolla key fob is acting up, before you consider complex repairs or reprogramming, try a truly new CR2016 battery from a reputable brand. It might just save you time, frustration, and unnecessary expense. And, perhaps learn from my mistake – buying batteries in bulk and storing them for extended periods might not be the best strategy for these small coin cells. From now on, I’ll be buying them only when I need them.
