The 2018 Toyota Corolla’s
OBD port is located underneath the far left side of the dashboard near the steering wheel—you should see it above the footrest and next to the hood release latch. It may or may not have a safety plug to prevent dust and other small particulate matter from accumulating in the port. When you’ve found the OBD port, insert your OBD scanner’s connector cable into it. In most cases, you’ll want to make sure that your Corolla’s ignition is in the “ON” position without actually starting the engine, but certain scanners require that you put the car in idle while utilizing the device. This is why it’s wise to always review and double-check the instructions that come with your scanner.
After waiting a few seconds, you should see a list of stored “active” and “pending” trouble codes, all starting with a letter followed by four numbers. These codes can then be deciphered using the following info:
P (Powertrain): indicates an issue with the fuel system, emissions system, transmission, ignition, or engine.
B (Body): indicates an issue with the airbags, seat belts, or power steering.
C (Chassis): indicates an issue with the anti-lock brake system, axles, or brake fluid.
U (Undefined): if an issue doesn’t fall into these three categories, it will appear as “undefined.”
The numbers, on the other hand, can be read as follows:
1st digit: tells you if the error code is generic (0) or manufacturer-specific (1)
2nd digit: refers to a specific part
Last two digits: tell you what the actual problem is