Leftover from LEAF
OBD-II Code Reader
for my Ioniq 5

Mark D Larsen

February 1, 2024

One feature that I have missed in my Nissan LEAF is the ability to tap into its On-Board Diagnostic (OBD) port to monitor the inner workings of its drivetrain —something that I couldn’t do with my Model 3. While perusing clips on YouTube the other day, I was intrigued to find this video, in which the “Ioniq Guy,” explains how to do this in an Ioniq 5.

Fortunately, I still have the old OBD-II code reader that I used with software like “LEAFStat” and “LEAF Spy” in my LEAF, so I wondered if it would still work with the recommended “Car Scanner” app on my iPhone. My OBD-II tool is no longer for sale, but there are many other alternatives available. The disadvantage is that other such code readers now use Bluetooth to communicate a car’s stats, but mine uses Wi-Fi. That’s no big deal: it still works just fine!

NOTE: You can click on the following photos to enlarge them.

One advantage of my old OBD-II device is that it plugs in horizontally, and is thus less intrusive into a car's footwell. Here it is plugged into the OBD port under the dashboard of Ohm My.

You can barely notice it looking down through the steering wheel towards the floor.

Another advantage of my OBD-II tool is that it boasts an "on/off" button, shown here looking up under the dashboard from the floor.

When turned on, its lights glow as in the previous photo, and the blue one starts blinking to indicate that it is ready to connect, clearly visible in the footwell.

To connect, I have to open the Wi-Fi settings on my iPhone and select the tool instead of my home's router.

I can then launch "Car Scanner" to connect to the OBD-II code reader. The opening screen shows a myriad of different options to access the car's data.

Probably the most comprehensive option is to select the "dashboard" which opens this initial screen with numerous readouts. I've highlighted in blue the top left box showing the State-of-Charge (SOC) in my Ioniq 5. I had charged to 80% the day before, and the readout now reported 79.5%, so I had lost a half-a-percent to vampire loss overnight. Not bad!

It is mind boggling that there are so many data points reported in "Car Scanner": by swiping left you can scroll through a total of 27 (!) different screens with additional tables of information and several graphs. In this photo I have swiped to the table that shows the battery's State-of-Health (SOH) in the box in the upper right corner. As you can see, my brand new Ioniq 5's pack is at… 100% capacity.

I plan to use this diagnostic tool periodically to ascertain how well the drivetrain and battery are holding up over time, just like I did with my LEAF —which enabled me to determine that it qualified for a new battery, just one month before the warranty expired!