STOP AND START SYSTEM, Diagnostic DTC:P164400

DTC Code DTC Name
P164400 ECU Internal Error

DESCRIPTION

If a malfunction is detected in the starter circuit, the engine stop and start ECU stores DTC P164400 and blinks the stop and start cancel indicator.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Memory Note
P164400 ECU Internal Error

Both of the following conditions are met for 0.2 seconds or more (1 trip detection logic):


  • Engine switch on (IG)

  • Malfunction in starter circuit (STA or STA2).


  • Wire harness or connector

  • ST relay

  • ST NO. 2 relay

  • Engine stop and start ECU

Blinks DTC stored SAE Code: P1644

CONFIRMATION DRIVING PATTERN


  1. Tech Tips


    • If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed.

      In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item Status of Battery Charge Control changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (52°F) or higher, the refresh charge will be completed.)

    • If the GTS is not available and the Data List item Status of Battery Charge Control cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.

      If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.

    • After the refresh charge completes, turn the engine switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.

    • Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.

    CONFIRMATION AFTER TROUBLESHOOTING


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs.


      Powertrain > Stop and Start > Clear DTCs
    5. Start the engine and warm it up.

    6. Drive the vehicle at 7 km/h (4.3 mph) or more.

      CAUTION:

      When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

    7. Depress the brake pedal and stop the vehicle.

    8. Allow the engine to stop by stop and start control. (Keep the shift lever in D.)

    9. Release the brake pedal with the shift lever in D to start the engine.

    10. Check that DTCs are not output.


      Powertrain > Stop and Start > Trouble Codes
  2. STOP AND START SYSTEM OPERATION CHECK

    Tech Tips


    • If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed.

      In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item Status of Battery Charge Control changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (52°F) or higher, the refresh charge will be completed.)

    • If the GTS is not available and the Data List item Status of Battery Charge Control cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.

      If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.

    • After the refresh charge completes, turn the engine switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.


    1. Start the engine and warm it up.

    2. Turn the air conditioning system off.

    3. Drive the vehicle at 7 km/h (4.3 mph) or more.

      CAUTION:

      When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

    4. Depress the brake pedal and stop the vehicle.

    5. Allow the engine to stop by stop and start control. (Keep the shift lever in D.)

    6. Release the brake pedal with the shift lever in D to start the engine.

WIRING DIAGRAM

Refer to DTC P061519.

Click here

CAUTION / NOTICE / HINT

Note


  • for 8AR-FTS:

    Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU.

    Click here

  • for 3ZR-FAE:

    When replacing the engine stop and start ECU with a new one, make sure to download the previous status (number of starter operations) of the old engine stop and start ECU. After replacing the engine stop and start ECU, turn the engine switch on (IG) and wait 20 seconds, then confirm that "OK" is displayed for the Data List item "Stop&Start Operating Permission (Discharged Oil Pump Air)". Then upload the previous status (number of starter operations) to the engine stop and start ECU.

    Click here

  • After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.

    Click here

  • After replacing the engine stop and start ECU or airbag sensor assembly, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU.

    Click here

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

Tech Tips


  • If DTCs P060B1C (Analog to Digital Converter Circuit Voltage Out of Range), P060B49 (Analog to Digital Converter Internal Electronic Failure) or P060B71 (Analog to Digital Converter Actuator Stuck) and P164400 (ECU Internal Error) are output simultaneously, perform troubleshooting for DTC P060B1C, P060B49 or P060B71 first as it may have caused DTC P164400 to be stored.

    Click here

  • If DTCs P061519 (Starter Relay Circuit Current Above Threshold) and P164400 (ECU Internal Error) are output simultaneously, perform troubleshooting for DTC P061519 first as it may have caused DTC P164400 to be stored.

    Click here

  • Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.

    Click here

  • DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.

    Click here

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P164400)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Stop and Start / Trouble Codes.

    5. Read the DTCs.


      Powertrain > Stop and Start > Trouble Codes
      Result
      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

      Tech Tips

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


    B
    C
    A
  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 No. 1 engine room relay block and junction block.

    3. Disconnect the certification ECU (smart key ECU assembly) connector.

    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
      A38-21 (STA) - ST relay terminal 2 Always Below 1 Ω
      A38-21 (STA) or ST relay terminal 2 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  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.

    4. Remove the ST relay from No. 1 engine room relay block and junction block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A38-21 (STA) - C14-9 (L) Always Below 1 Ω
      A38-21 (STA) or C14-9 (L) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. INSPECT RELAY (ST RELAY)


    1. Inspect the ST relay.


      Result
      Proceed to
      OK
      NG

    NG
    OK
  5. CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND)


    1. Remove the ST relay from No. 1 engine room relay block and junction block.

    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
      Result
      Proceed to
      OK
      NG

    NG
    OK
  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 No. 2 engine room relay block and junction block.

    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
      A38-23 (STA2) - ST NO. 2 relay terminal 2 Always Below 1 Ω
      A38-23 (STA2) or ST NO. 2 relay terminal 2 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  7. INSPECT RELAY (ST NO. 2 RELAY)


    1. Inspect the ST NO. 2 relay.


      Result
      Proceed to
      OK
      NG

    NG
    OK
  8. CHECK HARNESS AND CONNECTOR (ST NO. 2 RELAY - BODY GROUND)


    1. Remove the ST NO. 2 relay from No. 2 engine room relay block and junction block.

    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
      Result
      Proceed to
      OK
      NG

    OK
    NG