Why does the triangle warning light stay on after turning off a BMW?
2 Answers
It is normal for the triangle warning light to remain on after turning off a BMW, and it will automatically turn off later. General fault indicator light: The exclamation mark inside a yellow triangle on the dashboard is the general fault indicator light. The yellow triangle with an exclamation mark in the middle is the traction control system indicator, also known as the ground grip control system indicator. This light comes on to remind you to turn off the traction control system. If this light stays on while the traction control system is active, it indicates a problem with the TCS. Sometimes the light remains on, but after turning off and restarting the engine, it returns to normal. Tire pressure monitoring indicator: The exclamation mark inside yellow parentheses on the dashboard is the tire pressure monitoring indicator. It indicates that the tire pressure in one of the tires is insufficient, and you should check the tire pressure at a tire shop or a 4S store. The tire pressure should be the same for both front tires and the same for both rear tires. After adjusting the tire pressure to normal, the indicator light may still be on. In this case, turn the ignition key to the "on" position and press and hold the tire pressure monitoring switch for a few seconds, and the indicator light will turn off. Automatic transmission fault warning light: The exclamation mark inside a yellow gear on the dashboard is the automatic transmission fault warning light. It indicates a fault in the transmission, or that the transmission lubricant is below the normal range, or that the lubricant needs to be replaced.
Back when I worked at the repair shop, BMW owners often asked about this issue. That triangle light staying on after turning off the engine is primarily the normal operation of the anti-theft indicator system. When the car is turned off, although the engine stops, the electronic systems continue to receive power in the background for a while. The anti-theft module keeps monitoring the doors and key position to ensure no unauthorized access. Normally, this light will automatically turn off after a few minutes, serving as a reminder that the anti-theft system is active and helping to deter thieves. If the light stays on too long or doesn't turn off, it might be due to low battery causing unstable power supply or a minor fault in the anti-theft sensor. In such cases, it's best to check if the car key is away from the vehicle, lock the doors, and wait for it to turn off, or simply refer to the owner's manual to confirm the icon's meaning. Having technicians test the system during regular maintenance can prevent major issues. While it doesn't affect driving overall, don't ignore these small details to prevent potential safety hazards from escalating.
