What is the button on the back of the ETC device?

[PeterAnn]

The button on the back of the ETC device is an anti-tamper button. When the vehicle owner installs the ETC device on the windshield, the button is pressed down. If the device is moved or removed without authorization, the pressed button will pop up, and all vehicle information recorded by the device will be reset to zero. In this case, the owner needs to bring the device and relevant documents to the ETC service center for reactivation. Precautions for using ETC: The ETC transaction sensing range is 8 meters. When encountering a stationary vehicle ahead, to prevent the ETC device of the preceding vehicle from malfunctioning or not having an ETC device at all, maintain a distance of more than 10 meters to avoid automatic sensing and paying for the preceding vehicle. The ETC lane recognition speed is 20 km/h. If the vehicle speed is too fast, the device information cannot be read, which may also lead to payment failure. Unauthorized removal or movement of the OBU device, or detachment or loosening of the ETC electronic tag, will cause the electronic tag to become invalid. It can be sent to the bank where the ETC card was issued or the highway service office for inspection. If the detachment or loosening is not caused by human factors, it only needs to be reactivated. When using a debit card to bind ETC, insufficient balance may also cause payment failure. Follow the guidance of on-site staff to use the manual MTC lane and pass through by cash or card payment. If the vehicle's windshield is too thick, it may cause poor sensing. This is especially important for vehicles that have had their windshields replaced after an accident or for those who have modified their front windshields.

[StTimothy]

Last night while driving my friend's new car, I noticed a small button prominently placed behind the ETC. I've encountered similar designs before - that's actually the red SOS button for activating the vehicle's emergency rescue system. During major accidents when airbags deploy, it automatically sends location data, and you can also press and hold it to connect with customer service. The button usually has a plastic cover to prevent accidental presses, with a hidden microphone underneath for communication. This feature has become standard equipment in new cars nowadays, often integrated with services like OnStar or HondaLink.

[StSimon]

During the last vehicle inspection for a client, I noticed this detail—the metal button beneath the ETC card slot is actually the mute button for the car's anti-theft alarm. When the system falsely triggers continuous flashing and honking, pressing and holding it for three seconds can deactivate the alarm. Some automakers integrate this button with fingerprint recognition, but in base models, it's just a small round button with an indicator light that glows blue when pressed, signaling standby mode.

[OJuliet]

The button next to the ETC in my old Toyota is actually used to manually deactivate the door sensor. When picking up my kids, I often encounter situations where the key in my bag accidentally unlocks the doors—pressing this button temporarily disables the sensor function. The button features a door icon with a diagonal slash, has a matte texture during the day, and emits a soft green glow at night.