What is the reason why the car alarm sounds and cannot start?
4 Answers
Car alarm sounds and cannot start for the following reasons: Excessive sensitivity of the anti-theft device: The anti-theft device is too sensitive. There is a sensitivity adjustment knob on the vibration sensor of the anti-theft device, and a slight adjustment can solve the problem. Main control door grounding wire failure: Main control door grounding wire failure, commonly known as door switch failure. The car anti-theft alarm is a multifunctional product, not only for anti-theft alarm purposes, but also for remote trunk opening, remote door opening/closing, remote window opening/closing, remote engine starting, and remote engine locking. When the main control door grounding wire fails, it can cause the car alarm to sound and prevent the engine from starting.
When it comes to the car's anti-theft alarm going off and the engine not starting, the most common cause in my years of car experience is the activation of the anti-theft system. When the remote key's battery is nearly dead, the signal fails to transmit, and the anti-theft system assumes a theft attempt, triggering the alarm and locking the ignition. Don’t panic—first, try replacing the remote key’s button battery, usually a CR2032 model, available at convenience stores for around ten bucks. If changing the battery doesn’t work, check if the car’s main battery is low on charge; a voltage below 12V means it’s nearly depleted, requiring a jump-start or replacement. If that still doesn’t resolve the issue, the anti-theft module might have a bug, such as the doors not being properly closed during the last shutdown or a system glitch. Insert the key into the ignition switch and hold the unlock button for 10 seconds to reset it. For more complex issues like loose wiring or a faulty sensor, it’s best to visit a professional shop. Throughout the process, stay calm and prioritize safety—ensure the environment is well-ventilated before attempting to start the car.
Buddy, I ran into the same issue a while ago. My old van's alarm was blaring but it just wouldn't start. After struggling for hours, I realized the remote key battery was dead. Changed to a new battery and problem solved instantly - so simple! I suggest you try replacing the key battery first, just a few bucks at the supermarket. If that doesn't work, it's probably because the car battery is too low and the anti-theft system automatically locked the engine. Pop the hood to check if the battery terminals are corroded, clean them and check the voltage - use a multimeter or judge by dashboard light brightness. If it still won't start, don't force it - might be anti-theft false alarm like signal interference from parking in wrong spots, or your phone/other devices interfering with key signals. Try moving away and retrying. Always start with the simplest solutions to save money and hassle.
The anti-theft alarm sounding and failure to start are usually caused by simple issues. For example, a depleted remote key battery can activate the anti-theft alarm and prevent the engine from starting. Solution: Try replacing it with a new battery. If that doesn't work, check if the car battery is dead, as low voltage can also trigger the anti-theft system. If the key is functioning normally, it might be a software error in the anti-theft system requiring a reset. Try starting the car with a spare key. In severe cases, such as module failure, a repair shop will need to handle it. Regular maintenance can help prevent such issues.
