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DTC P1644-00: ECU Internal Error [11/2016 - ]: Procedure

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  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P164400) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Stop and Start / Trouble Codes.
    5. Read the DTCs.

      Powertrain > Stop and Start > Trouble Codes 

      Result Proceed to
      DTC P164400 is output A
      DTCs P060B1C, P060B49 or P060B71 and P164400 are output B
      DTCs P061519 and P164400 are output C

      HINT: 

      If DTCs P060B1C, P060B49, P060B71 or P061519 and P164400 are output simultaneously, troubleshoot for DTC P060B1C, P060B49, P060B71 or P061519 first.

    Result: 

    B 

    GO TO DTC P060B1C, P060B49 OR P060B71.  Refer to DTC P060B-1C: Analog to Digital Converter Circuit Voltage Out of Range; DTC P060B49: Analog to Digital Converter Internal Electronic Failure; DTC P060B71: Analog to Digital Converter Actuator Stuck [11/2016 - ] .

    Result: 

    C 

    GO TO DTC P061519.  Refer to DTC P0615-19: Starter Relay Circuit Current Above Threshold [11/2016 - ] .

    Result: 

    A 

    Go to next step 

  2. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST RELAY) 
    1. Disconnect the engine stop and start ECU connector.
    2. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    3. Disconnect the certification ECU (smart key ECU assembly) connector. (w/ Smart Key System)
    4. Disconnect the park/neutral position switch assembly connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A92-21 (STA) - ST relay terminal 2 Always Below 1 Ω
      A92-21 (STA) or ST relay terminal 2 - Body ground and other terminals Always 10 kΩ or higher
      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    Go to next step 

  3. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - PARK/NEUTRAL POSITION SWITCH ASSEMBLY) 
    1. Disconnect the engine stop and start ECU connector.
    2. Disconnect the park/neutral position switch assembly connector.
    3. Disconnect the certification ECU (smart key ECU assembly) connector. (w/ Smart Key System)
    4. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A92-21 (STA) - C14-9 (L) Always Below 1 Ω
      A92-21 (STA) or C14-9 (L) - Body ground and other terminals Always 10 kΩ or higher
      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    Go to next step 

  4. INSPECT RELAY (ST RELAY) 
    1. Inspect the ST relay.

      Refer to PROCEDURE - Step 1

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE RELAY (ST RELAY) 

    Result: 

    OK 

    Go to next step 

  5. CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND) 
    1. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      ST relay terminal 1 - Body ground Always Below 1 Ω
      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    Go to next step 

  6. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST NO. 2 RELAY) 
    1. Disconnect the engine stop and start ECU connector.
    2. Remove the ST NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    3. Disconnect the ECM connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A92-23 (STA2) - ST NO. 2 relay terminal 2 Always Below 1 Ω
      A92-23 (STA2) or ST NO. 2 relay terminal 2 - Body ground and other terminals Always 10 kΩ or higher
      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    Go to next step 

  7. INSPECT RELAY (ST NO. 2 RELAY) 
    1. Inspect the ST NO. 2 relay.

      Refer to PROCEDURE - Step 2

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE RELAY (ST NO. 2 RELAY) 

    Result: 

    OK 

    Go to next step 

  8. CHECK HARNESS AND CONNECTOR (ST NO. 2 RELAY - BODY GROUND) 
    1. Remove the ST NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      ST NO. 2 relay terminal 1 - Body ground Always Below 1 Ω
      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ENGINE STOP AND START ECU.  Refer to REMOVAL [11/2016 - ] .

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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