Understanding your car’s voltage is crucial for maintaining its health and preventing unexpected breakdowns. A car scanner app can be an incredibly useful tool for monitoring this vital sign, among other things. This FAQ guide answers common questions about using car scanner apps, particularly focusing on how to check your car’s voltage and what those readings mean.
Common Questions About Car Scanner Apps
Q: What is a car scanner app and how does it work?
A: A car scanner app is a software application designed to communicate with your car’s onboard computer system, typically through an OBDII (On-Board Diagnostics II) port. This port is standard on most modern vehicles. To use a car scanner app, you’ll need an OBDII adapter that plugs into this port. The adapter then connects wirelessly (usually via Bluetooth or Wi-Fi) to your smartphone or tablet running the car scanner app. Once connected, the app can read various data points from your car’s computer, including engine parameters, sensor readings, and diagnostic trouble codes (DTCs).
Q: Can I really use a car scanner app to see my car’s voltage?
A: Yes, absolutely! Monitoring your car’s voltage is one of the most basic yet important functions of a car scanner app. The app reads the voltage data directly from your car’s computer system. This reading usually reflects the voltage of your car’s battery and the charging system.
Q: Why is it important to check my car’s voltage?
A: Monitoring your car’s voltage is important for several reasons:
- Battery Health: Voltage readings are a primary indicator of your car battery’s health. A healthy battery should maintain a certain voltage range. Deviations can signal a failing battery, allowing you to address the issue before it leaves you stranded.
- Charging System Issues: Voltage drops or spikes can point to problems with your car’s charging system, such as the alternator. Identifying these issues early can prevent more significant and costly repairs.
- Preventing Breakdowns: By keeping an eye on your car’s voltage, you can proactively identify and address potential electrical problems before they escalate into breakdowns.
- Performance Monitoring: In some cases, voltage fluctuations can affect the performance of various car components. Monitoring voltage can help diagnose performance issues related to electrical supply.
Q: What voltage readings should I expect to see with a car scanner app?
A: Typical voltage readings you might see using a car scanner app, and what they generally indicate, are:
- Engine Off (Key in ACC or ON position, but engine not running): Ideally, you should see around 12.2 to 12.6 volts. Readings below 12 volts indicate a battery that is discharged or potentially failing.
- Engine Running (Idling): With the engine running, the alternator should be charging the battery. You should see a voltage reading between 13.7 to 14.7 volts. Readings outside this range can indicate problems with the alternator or charging system.
- Under Heavy Load (e.g., headlights, AC, etc., ON): Voltage might drop slightly under heavy electrical load, but it should still remain within the 13.5 to 14.5 volt range.
Q: My car scanner app only displays “ELM volts.” What does this mean?
A: When your car scanner app displays “ELM volts,” it’s showing the voltage reading reported by your ELM327 adapter itself. This is often the voltage supplied to the adapter. While it can give a general idea, it’s not always the most accurate representation of your car’s battery voltage. Ideally, you want to look for a sensor reading within the app that is specifically labeled “Battery Voltage,” “System Voltage,” or something similar, which reads directly from the car’s computer.
Q: The voltage reading in my car scanner app seems incorrect! What could be the problem?
A: If you suspect the voltage reading is incorrect, consider these factors:
- Adapter Quality: Low-quality or “clone” ELM327 adapters, especially cheaper Chinese versions, are known to sometimes report inaccurate voltage readings. This is a common issue. If you suspect your adapter is the culprit, try using a different, reputable OBDII adapter.
- App Glitches: While less common, the car scanner app itself could have a temporary glitch. Try restarting the app and reconnecting to your adapter and car.
- Car’s Electrical System Issues: In rare cases, a genuinely faulty reading might indicate a severe problem within your car’s electrical system that’s affecting the voltage data being reported to the computer. However, adapter or app issues are far more likely.
- “ELM Volts” vs. System Voltage: Make sure you are looking at the correct voltage parameter within the app (System Voltage, Battery Voltage, etc.) and not just the “ELM Volts” reading which is adapter voltage.
Q: I’ve connected to my car, but the app only shows “ELM volts” and no other data.
A: This is often seen in older vehicles, particularly some older Nissan, Renault, and Subaru models. These cars may have very limited OBDII support. Their OBDII system might only be functional for reading and clearing diagnostic trouble codes (DTCs) and doesn’t provide live data streams like voltage or other sensor readings via the standard OBDII protocol. For some older Nissan cars, you might have better luck using a Nissan Consult II protocol option within the app, if available, to access more data.
Q: Can I use any OBDII adapter with a car scanner app to see voltage?
A: In theory, yes, any functional OBDII adapter should allow you to see voltage readings, assuming your car’s computer provides this data through the OBDII port (which most modern cars do). However, as mentioned earlier, adapter quality can affect the accuracy of the reading. For reliable voltage monitoring, it’s advisable to use a quality, recommended OBDII adapter.
Q: What kind of OBDII adapter should I use for checking voltage with a car scanner app?
A: For reliable performance and accurate voltage readings, it’s recommended to choose a quality OBDII adapter. For iOS devices (iPhones and iPads), you’ll need a Bluetooth 4.0 (LE) adapter or a Wi-Fi adapter. “Classic” Bluetooth adapters are not compatible with iOS. For Android devices, both Bluetooth and Wi-Fi adapters can work. When selecting an adapter, consider brands known for quality and positive user reviews. Avoid extremely cheap, unbranded adapters, as these are more likely to be unreliable and potentially provide inaccurate readings.
iOS Specific Questions
Q: My iPhone/iPad says “Not supported” when I try to connect to a Bluetooth adapter in the iOS settings.
A: This is normal! You do not need to pair Bluetooth OBDII adapters in your iPhone or iPad’s Bluetooth settings. For Bluetooth 4.0 (LE) adapters, the connection is handled directly within the car scanner app. Simply ensure Bluetooth is enabled on your iOS device and follow the app’s connection instructions.
Q: Does Car Scanner app support Bluetooth ELM327 adapters on iOS?
A: Yes, Car Scanner on iOS supports Bluetooth 4.0 (LE) ELM327 adapters. It does not support older “classic” Bluetooth adapters due to Apple’s iOS limitations.
Q: I’m having trouble connecting with a Wi-Fi adapter on my iPhone/iPad.
A: For Wi-Fi OBDII adapters on iOS, you need to manually connect your iPhone or iPad to the Wi-Fi network broadcast by the adapter before opening the Car Scanner app. This Wi-Fi network will typically have a name like “OBDII,” “obd2,” or “OBDII_WIFI.” You connect to this network in your iOS Settings under Wi-Fi. Once connected to the adapter’s Wi-Fi network, you can then open the Car Scanner app and establish the connection within the app.
Q: My connection drops when I minimize the app or receive a call on my iPhone/iPad.
A: This is a limitation of iOS. Apple’s operating system restricts apps from continuously running in the background and maintaining Wi-Fi connections. Therefore, using a Wi-Fi adapter, the connection might be interrupted when the app is minimized or interrupted by phone calls. Bluetooth 4.0 (LE) adapters generally offer better background connectivity on iOS, but even these connections can be terminated by iOS if the operating system decides to free up resources.
Android Specific Questions
Q: Can the Car Scanner app run in the background on Android?
A: Yes, Car Scanner can run in the background on Android, allowing you to monitor voltage and other parameters while using other apps or even with your screen off. To enable this, you need to activate the “Work in background” option in the app’s Settings under the “Connection” section. Some Android devices and OS versions might require you to add Car Scanner to a “whitelist” or exception list to prevent the Android operating system from aggressively closing the app when it’s running in the background. This ensures continuous voltage monitoring.
By understanding these FAQs, you should be well-equipped to use a car scanner app to effectively monitor your car’s voltage and gain valuable insights into your vehicle’s electrical health. Remember to always use a reliable OBDII adapter and consult your vehicle’s repair manual or a qualified mechanic for any concerning voltage readings or electrical issues.
