Reading Codes

If the check engine light comes on while the vehicle is running or driving, it indicates that the computer has detected a malfunction with one or more engine components, sensors or harness wiring, and a code has been set.

In order to retrieve the trouble code(s), you must have the Mazda system selector 49 B019 9A0 and self diagnosis checker (a digital readout tool) 49 H018 9A1 or an equivalent OBD I compliant scan tool for 1990–95 (except 1994–95 626 with ATX and 1995 Protege and Millenia) models. For 1994–95 626 with ATX, 1995 Protege and Millenia and all 1996–98 Models, you must have an OBD I (1994–95 626 with ATX only) or OBD II compliant scan tool.

1994–95 626 with ATX transmission, 1995 Protege and Millenia and 1996–98 Models

1. Ensure that the ignition switch is in the OFF position.
2. Attach an OBD II compliant scan tool to the data link connector-2, located beneath the drivers side of the dash panel, as instructed by the tool manufacturers directions.
3. Follow the manufacturers instructions for initializing the scan tool and performing the appropriate test procedures (key on engine off, key on engine running, output control test, etc.).
4. Read the trouble code, or codes, on the scan tool and record them.

Except 1994–95 626 with ATX transmission, 1995 Protege and Millenia and 1996–98 Models

1. Ensure that the ignition switch is in the OFF position.
2. Attach the Mazda system selector and self diagnosis tools or equivalent scan tool to the data link connector as instructed by the tool manufacturers directions.
3. Turn the ignition switch to the ON position.
4. Read the trouble code, or codes, on the scan tool and record them.