Why is the car lock symbol flashing on the Corolla dashboard?

[ONoah]

The reason why the car lock symbol on the Corolla dashboard keeps flashing is that the anti-theft system is active. When the car doors are locked, the vehicle automatically enters anti-theft mode, at which time the key light will flash continuously. The engine's anti-theft system consists of an electronic chip embedded inside the car key. Each chip has a fixed ID, and the car can only start when the key chip's ID matches the engine's ID. If they don't match, the car will immediately cut off power automatically, preventing the engine from starting. When the car is left unlocked, the electronic anti-theft system enters sleep mode, and the warning light flashes once every 5 seconds. If the light is off, it means the anti-theft system is not functioning and has failed to enter the working state. In this case, you need to check the display settings to find the remote lock mode setting and enable the horn with light flashing when locking.

[DianaLee]

I've been driving a Corolla for many years, and the flashing car lock icon on the dashboard is quite common. It mainly indicates the anti-theft system is active—after you turn off the engine and lock the car, it keeps flashing to show the vehicle is under protection. It could also mean a door isn’t fully closed, or the trunk or hood isn’t securely latched, making the sensor suspect a break-in and trigger the alert. Another possibility is the remote key fob battery running low, weakening the signal and causing the system to act suspiciously. More rarely, it might be a fault in the body control module, requiring a diagnostic scan. Honestly, just make sure doors are properly closed and keep spare batteries handy for replacement. Occasional flashing isn’t a big deal, but if it persists for days, it’s best to visit a workshop to check the wiring.

[Benjamin]

My Corolla also had the issue of the lock indicator flashing when it was new, which is actually related to the anti-theft system settings. After turning off the engine and moving the key away, the dashboard will slowly flash to indicate the vehicle is locked. If it flashes quickly, check if all doors are properly closed, especially the rear doors where the child lock might get stuck half-open. Insufficient battery in the remote key is the most easily overlooked issue—the coin cell battery tends to degrade after two years, so try replacing it with a new one that costs just five yuan. Dirty sensors or moisture during rainy days can also cause false alarms; simply wipe the door frame contacts. Don’t rush to the dealership; trying these simple methods yourself can save time.

[CameronDella]

The flashing lock light on the Corolla dashboard may indicate normal operation of the anti-theft system, often staying lit to show protection status after parking and locking. If it flashes while driving, it's likely a door isn't properly closed—try shutting it again. An unsecured trunk can also trigger this; press it firmly to check. When the remote key fob's battery is low, weak signals may cause the lock symbol to flash erratically as a reminder to replace the battery. Foreign objects stuck in the window can interfere with sensor lines, leading to flashing too. These issues are usually DIY-fixable without much worry, unless frequent occurrences warrant checking the circuit.