If the MIL (malfunction indicator lamp) has come on

Start the engine, and check the MIL (A).
NOTE: If the ignition switch is turned to ON (II), and the engine is not started, the MIL stays on for 15-20 seconds (see MALFUNCTION INDICATOR LAMP (MIL) INDICATION (IN RELATION TO READINESS CODES) ).

Fig 1: Identifying MIL (Malfunction Indicator Lamp)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the MIL stays on, connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.

Fig 2: Identifying Data Link Connector (DLC)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Make sure the HDS communicates with the ECM/PCM and all other vehicle systems. If it doesn't, go to the DLC circuit troubleshooting (see DLC CIRCUIT TROUBLESHOOTING ).
Check the diagnostic trouble code (DTC) and note it. Also check the freeze data and/or on-board snapshot data, and download any data found. Then refer to the indicated DTC'S TROUBLESHOOTING , and begin the appropriate troubleshooting procedure.
NOTE:
- Freeze data indicates the engine conditions when the first system malfunction, misfire, or fuel trim malfunction that activated the MIL was detected.
- The HDS can read the DTC, freeze data, on-board snapshot, current data, and other engine control module (ECM) or powertrain control module (PCM) data.
- For specific operations, refer to the that came with the HDS.
If no DTCs are found, go to MIL troubleshooting (see MIL CIRCUIT TROUBLESHOOTING ).