An OBD2 sensor, while plugged in, doesn’t inherently indicate whether a car’s engine is running. It only powers on and transmits data when the vehicle’s ignition is in the ‘on’ position (key turned or engine running). This means the sensor can be active even if the engine isn’t running, but the car is ready to start. To definitively determine if the engine is running, you need additional information.
One method is to leverage the car’s accessory power outlets. These outlets are typically only live when the engine is running. By connecting a device (like a beacon) to the accessory outlet and monitoring its status, you can infer whether the engine is on. If the beacon is active, the engine is running. This, combined with confirming a closed garage door, could indicate a potentially hazardous situation (car running in a closed garage).
However, this approach isn’t foolproof. A false positive could occur if the car is on the driveway with the engine running and the garage door is closed. Therefore, solely relying on the accessory power and garage door status might not be sufficient.
Alternatively, a Bluetooth beacon placed inside the car and a receiver in the garage can help. By measuring the beacon’s signal strength, you can distinguish between the car being parked inside the garage versus on the driveway due to proximity. Stronger signal strength indicates the car is within the garage. Combining this with the accessory-powered beacon provides a more robust solution – confirming both car presence in the garage and engine operation.
Another approach utilizes an ultrasonic sensor within the garage to detect the car’s presence. When combined with the accessory-powered beacon, this setup confirms both the car’s location inside the garage and the engine’s running status, offering a more reliable detection system. This eliminates the driveway false positive scenario.
While carbon monoxide (CO) detectors can alert to dangerous CO buildup, using them for this specific purpose requires a detector capable of transmitting a remote warning signal that can trigger an action, such as opening the garage door or sending a notification. Finding a CO detector with this capability is crucial for this method to be effective.
To summarize, determining if a car’s engine is running using only an OBD2 sensor isn’t possible. However, combining the OBD2 data with information from accessory power status, Bluetooth beacon signal strength, or ultrasonic sensors can provide a reliable system for detecting a running car inside a closed garage and potentially preventing a hazardous situation.
