STOP AND START SYSTEM, Diagnostic DTC:P1780

DTC Code DTC Name
P1780 Discrepancy between Neutral Position SW and Shift Position

DESCRIPTION

The engine stop and start ECU detects malfunctions by comparing the condition of the shift position signal and neutral position switch signal. If a malfunction occurs, the engine stop and start ECU stores this DTC, blinks the stop and start cancel indicator light, and prohibits stop and start control.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

P1780

Discrepancy between Neutral Position SW and Shift Position

The following condition continues for 1 second or more (1 trip detection logic):

  • Open or short in neutral position switch circuit.

  • Neutral position switch

  • Engine stop and start ECU

  • Wire harness or connector

Blinks

DTC stored

WIRING DIAGRAM

A285528E15

CAUTION / NOTICE / HINT

Note:

  • Before replacing the engine stop and start ECU, download the current status (number of starter operations) and upload it into a new engine stop and start ECU.

    Click here

  • After replacing the engine stop and start ECU or air conditioning control assembly, initialize 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

Tip:

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.

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PROCEDURE

  1. READ VALUE USING GTS (NEUTRAL SWITCH)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Stop and Start / Data List / Neutral Switch.

    5. According to the display on the GTS, read the Data List.

      Powertrain > Stop and Start > Data List

      Tester Display

      Neutral Switch

      OK

      Tester Display

      Condition

      Normal Condition

      Neutral Switch

      Shift lever in neutral

      ON

      Shift lever in any position other than neutral

      OFF

    Result

    Result

    Proceed to

    NG

    A

    OK

    B
    B

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    A

  2. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - NEUTRAL POSITION SWITCH)

    1. Disconnect the A24 engine stop and start ECU connector.

    2. Disconnect the A42 neutral position switch connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A24-26 (TMVC) - A42-1 (W1)

      Always

      Below 1 Ω

      A24-25 (TME2) - A42-3 (F+)

      Always

      Below 1 Ω

      A24-27 (TMN) - A42-2 (TMN)

      Always

      Below 1 Ω

      A24-26 (TMVC) - Body ground

      Always

      10 kΩ or higher

      A42-1 (W1) - Body ground

      Always

      10 kΩ or higher

      A24-25 (TME2) - Body ground

      Always

      10 kΩ or higher

      A42-3 (F+) - Body ground

      Always

      10 kΩ or higher

      A24-27 (TMN) - Body ground

      Always

      10 kΩ or higher

      A42-2 (TMN) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ENGINE STOP AND START ECU (TMN TERMINAL VOLTAGE)

    1. Measure the voltage according to the value(s) in the table below.

      A285225C59

      *a

      Component with harness connected

      (Engine Stop and Start ECU)

      -

      -

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A24-27 (TMN) - A24-25 (TME2)

      Ignition switch ON, shift lever in neutral

      2.7 to 4.3 V

      Ignition switch ON, shift lever in any position other than neutral

      0.7 to 1.9 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ENGINE STOP AND START ECU

    Click here

    NG

    REPLACE NEUTRAL POSITION SWITCH

    Click here