ECD SYSTEM, Diagnostic DTC:P0685

DTC Code DTC Name
P0685 ECM / PCM Power Relay Control Circuit / Open

DESCRIPTION

The battery supplies power to terminal +B and/or +B1 of the ECM even when the ignition switch is turned to off (up to 15 seconds).

P0685
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
After ignition switch is turned to off

Either of following conditions is met:

(1 trip detection logic)


  • After ignition switch is turned to off, voltage supplied to terminal +B and/or +B1 is cut earlier than minimum threshold duration.

  • After ignition switch is turned to off, voltage supplied to terminal +B and/or +B1 continues after threshold duration elapsed.

  • Open in ECD relay circuit.

  • ECD relay (No. 1 integration relay)

  • ECD fuse

  • ECM

Tech Tips

If DTC P0685 is stored, the ECM does not store other DTCs.

WIRING DIAGRAM

A005JHSE03

CAUTION / NOTICE / HINT

Note


  • When replacing the ECM, the ECM needs Registration and Initialization Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the intelligent tester. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.

PROCEDURE


  1. INSPECT NO.1 INTEGRATION RELAY


    1. Inspect the No. 1 integration relay Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)


    1. Remove the No. 1 integration relay from the engine room main relay block.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1D-7 - A59-22 (MREL) Always Below 1 Ω
      1E-4 - A59-1 (+B) Always Below 1 Ω
      1E-4 - A59-61 (+B2) Always Below 1 Ω
      1E-10 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1D-7 or A59-22 (MREL) - Body ground Always 10 kΩ or higher
      1E-4 or A59-1 (+B) - Body ground Always 10 kΩ or higher
      1E-4 or A59-61 (+B2) - Body ground Always 10 kΩ or higher

    4. Reinstall the No. 1 integration relay.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  3. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  5. REPLACE NO. 1 INTEGRATION RELAY


    1. Replace the No. 1 integration relay Click here.


    NEXT

  6. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Clear the DTCs Click here.

    4. Turn the ignition switch off and wait for 30 seconds or more.

    5. Turn the ignition switch to ON.

    6. Enter the following menus: Powertrain / Engine and ECT / DTC.

    7. Confirm that the DTC is not output again.


    NEXT

    END