Keeping an eye on your vehicle’s transmission temperature is crucial for maintaining its health and preventing costly repairs. Overheating can lead to significant damage, and thankfully, modern OBD2 scanners offer a way to monitor this vital metric. This guide will walk you through how to use an OBD scanner to check your transmission temperature, using the popular Veepeak OBDII scanner and Torque Pro app as an example.
To get started, you’ll need a few things. First, ensure you have a compatible OBD2 scanner. Many scanners utilizing the ELM327 protocol will work, including the Veepeak OBDII scanner mentioned. You’ll also need a smartphone or tablet to run the Torque Pro application (available on Android). Finally, make sure your vehicle is OBD2 compliant, which most modern cars are (typically post-1996 models in the US).
Once you have your equipment, the initial setup involves pairing your OBD scanner with the Torque Pro app and establishing a connection to your vehicle’s computer. After successfully connecting, you may need to configure a custom PID (Parameter ID) within Torque Pro to specifically read the transmission temperature. Navigate to the settings menu within Torque Pro, typically found under a gear icon, and look for options like “Manage extra PIDs/Sensors” or “Add Custom PID”.
To accurately monitor your transmission temperature, you’ll need to input specific PID information. Here’s an example of settings that have been reported to work for some vehicles:
- OBD2 Mode and PID: 222201
- Long Name: Transmission Temp F
- Short Name: ATF Temp
- Minimum value: -40
- Maximum value: 300
- Scale factor: x1
- Equation: AA*(9/5)-40
- Overrides PID: “Does not override any PIDs”
A critical step that might be necessary is setting the correct initialization string for your OBD2 scanner to communicate properly with your vehicle’s ECM (Engine Control Module). This string acts as a command to establish the right communication protocol. You can usually find this setting under “Vehicle Profile” and “Very Advanced” settings in Torque Pro. While a blank string might work, or the generic ATCAF1, specific strings have proven effective. For the Veepeak scanner and some vehicles, ath0 has been successful. Another string, atsp7natshda1df1, has also been reported to work. Experiment with these if you encounter connection issues or incorrect readings.
After setting up the custom PID and initialization string, you should be able to see your transmission temperature displayed within the Torque Pro app. It’s worth noting that during vehicle warm-up, the coolant temperature typically rises faster than the ATF (Automatic Transmission Fluid) temperature. However, once warmed up, the coolant temperature tends to stabilize, while the ATF temperature will fluctuate more depending on driving conditions and transmission load. This behavior is normal and expected when monitoring your transmission with an OBD scanner.
By following these steps, you can effectively use an OBD scanner and the Torque Pro app to monitor your transmission temperature, providing valuable insight into your vehicle’s health and helping to prevent potential transmission issues.
