Keeping an eye on your vehicle’s vital signs is crucial for preventative maintenance and ensuring longevity. Among these, monitoring your car’s temperature, especially the Automatic Transmission Fluid (ATF) temperature, can provide valuable insights into its health. I’ve found a fantastic and user-friendly solution that combines an OBD2 scanner and a mobile app, perfect for iPhone users who want to monitor these temperatures without needing advanced technical skills.
Previously, I relied on the OBD Fusion app and a custom PID (Parameter ID) to track my ATF temperature, a method shared within online car enthusiast communities. However, I transitioned to a new app because of its seamless, plug-and-play functionality. This new app automatically detects vehicle sensors, eliminating the need for complex custom setups. It’s an ideal choice if you prefer simplicity and want to avoid spending hours learning a new application or figuring out custom PID configurations. The app boasts a straightforward and intuitive interface, allowing for dashboard customization and the setting of personalized alerts.
The app I’m currently using is called “Car Scanner ELM OBD2,” and it’s available for free on the App Store. While the free version is fully functional, I opted for the pro version for a small fee to support the developer, who has created an exceptional tool.
For the OBD2 reader, I recommend the “Veepeak OBDCheck BLE+.” This scanner connects to your iPhone via Bluetooth, but the connection process is conveniently managed within the app itself, not through the iOS settings. To ensure full sensor access, it’s essential to use the exact connection profile as shown in the screenshots below. Once configured, it automatically connects every time I start my vehicle.
Below is an example of my customized dashboard. You can tailor yours to display the information most relevant to you. Notably, the ATF temperature reading aligns with the custom PID I previously used in OBD Fusion, confirming the accuracy of this app’s automatic sensor detection. I also have an S-VCM installed in my vehicle, and I’ve observed that the engine coolant temperature displayed is approximately 15°F cooler with the S-VCM in place. This is expected, as the S-VCM works by subtly altering the coolant temperature reading to the ECU to disable the Variable Cylinder Management (VCM) system.
