STOP AND START SYSTEM(for 2WW), Diagnostic DTC:P1780

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

DESCRIPTION

The engine stop and start ECU detects a malfunction by comparing the shift position signal with the neutral position sensor (neutral position switch) signal input state. When a malfunction occurs, the engine stop and start ECU stores this DTC, blinks the stop and start cancel indicator light, and prohibits the 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 sensor (neutral position switch) circuit.

  • Neutral position sensor (neutral position switch)

  • Engine stop and start ECU

  • Wire harness or connector

Blinks

DTC stored

WIRING DIAGRAM

A285528E26

CAUTION / NOTICE / HINT

Note:

  • 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.

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  • 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.

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

    Click here

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

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.

      Powertrain > Stop and Start > Data List

      Tester Display

      Neutral Switch

    5. Read the value when the shift lever is in neutral and any other position

      OK

      Tester Display

      Condition

      Normal Condition

      Neutral Switch

      Shift lever in neutral

      ON

      Shift lever in any position other than neutral

      OFF

    Result

    Proceed to

    OK

    NG
    OK

    USE SIMULATION METHOD TO CHECK

    Click hereClick here

    NG

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

    1. Disconnect the A66 engine stop and start ECU connector.

    2. Disconnect the C16 neutral position sensor (neutral position switch) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A66-26 (TMVC) - C16-1 (W1)

      Always

      Below 1 Ω

      A66-25 (TME2) - C16-3 (F+)

      Always

      Below 1 Ω

      A66-8 (TMN) - C16-2 (TMN)

      Always

      Below 1 Ω

      A66-26 (TMVC) - Body ground

      Always

      10 kΩ or higher

      C16-1 (W1) - Body ground

      Always

      10 kΩ or higher

      A66-25 (TME2) - Body ground

      Always

      10 kΩ or higher

      C16-3 (F+) - Body ground

      Always

      10 kΩ or higher

      A66-8 (TMN) - Body ground

      Always

      10 kΩ or higher

      C16-2 (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)

    A346331C72

    *a

    Component with harness connected

    (Engine Stop and Start ECU)

    -

    -

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A66-8 (TMN) - A66-25 (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

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    NG

    REPLACE NEUTRAL POSITION SWITCH

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