Tech Tips

Compared to normal mode, check mode is more sensitive to malfunctions. Therefore, check mode can detect the malfunctions that cannot be detected by normal mode.


All the stored DTCs and freeze frame data are cleared if: 1) the ECM is changed from normal mode to check mode or vice versa; or 2) the ignition switch is turned from on or off while in check mode. Before changing modes, always check and make a note of any DTCs and freeze frame data.


    1. Check that the following conditions are met:

      1. Battery positive voltage is 11 V or higher.

      2. Transmission is in neutral.

      3. A/C is switched off.

    2. Turn the ignition switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

    6. Enter the following menus: Utility / Check Mode.

      Powertrain > Engine > Utility
      Tester Display
      Check Mode
    7. Switch the ECM from normal mode to check mode.

    8. B0024YVE05
      *1 0.13 seconds
      *2 ON
      *3 OFF

      Make sure the MIL flashes as shown in the illustration.

    9. Start the engine.

    10. Make sure the MIL turns off.

    11. Simulate the conditions of the malfunction described by the customer.

    12. Check for DTCs and freeze frame data using the GTS.

      Powertrain > Engine > Trouble Codes
    13. After checking for DTCs, inspect the applicable circuits.