STOP AND START SYSTEM, Diagnostic DTC:P1780

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

DESCRIPTION

for Automatic Transmission:

The engine stop and start ECU detects malfunctions by comparing the conditions of the shift position signal and NSW signal. If a malfunction is detected, the engine stop and start ECU blinks the stop and start cancel indicator light, prohibits stop and start control and stores DTC P1780.

for Manual Transmission:

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

for Automatic Transmission:

Both of the following conditions are met for 2 seconds or more (2 trip detection logic) (*1):


  • Ignition switch ON

  • NSW signal is ON with the shift lever in D

Both of the following conditions are met for 2 seconds or more (2 trip detection logic) (*1):


  • Ignition switch ON

  • NSW signal is ON with the shift lever in R

Both of the following conditions are met for 15 seconds or more (2 trip detection logic) (*2):


  • Ignition switch ON

  • NSW signal is ON with the shift lever in P or N

for Manual Transmission:

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


  • Open or short in neutral position sensor (neutral position switch) circuit.

  • for Automatic Transmission:

    Park/neutral position switch assembly

  • for Manual Transmission:

    Neutral position sensor (neutral position switch)

  • Engine stop and start ECU

  • ECM

  • Wire harness or connector

 Blinks DTC stored

*1: "ON" is displayed for the freeze frame data item [Neutral Switch Stuck ON]

*2: "ON" is displayed for the freeze frame data item [Neutral Switch Stuck OFF]

WIRING DIAGRAM


  1. for Automatic Transmission:

    B0027RAE01

  2. for Manual Transmission:

    B00264RE11
    *a Neutral Position Sensor (Neutral Position Switch)
    *b Engine Stop and Start ECU

CAUTION / NOTICE / HINT

Note


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

  • When the ECM is replaced on a vehicle with a non-specified battery, it is necessary to perform battery type switching.

    Click here

  • for Automatic Transmission:

    When the engine stop and start ECU is replaced, check the electromagnetic oil pump.

    Click here

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

Tech Tips


  • 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. CONFIRM MODEL


    1. Choose the model to be inspected.

      Result
      Result Proceed to
      for Automatic Transmission A
      for Manual Transmission B

    B

    READ VALUE USING GTS (NEUTRAL SWITCH) Click here

    A

  2. READ VALUE USING GTS


    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 / Engine and ECT / Data List.

    5. In accordance with the display on the GTS, read the Data List.


      Powertrain > Engine and ECT
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Shift SW Status (P Range) Park/neutral position switch assembly status OFF or ON

      OFF: Shift lever not in P

      ON: Shift lever in P

      		 -
      Shift SW Status (R Range) Park/neutral position switch assembly status OFF or ON

      OFF: Shift lever not in R

      ON: Shift lever in R

      		 -
      Shift SW Status (N Range) Park/neutral position switch assembly status OFF or ON

      OFF: Shift lever not in N

      ON: Shift lever in N

      		 -
      Shift SW Status (D Range) Park/neutral position switch assembly status OFF or ON

      OFF: Shift lever not in D or S

      ON: Shift lever in D or S

      		 -

      Powertrain > Engine and ECT > Data List
      Tester Display
      Shift SW Status (P Range)
      Shift SW Status (R Range)
      Shift SW Status (N Range)
      Shift SW Status (D Range)
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    OK

  3. READ VALUE USING GTS (NEUTRAL POSITION SW OR NEUTRAL POSITION SW SIGNAL)


    1. Enter the following menus: Powertrain / Engine and ECT / Data List.

    2. In accordance with the display on the GTS, read the Data List.


      Powertrain > Engine and ECT > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Neutral Position SW Signal Park/neutral position switch assembly status OFF or ON

      OFF: Shift lever not in P or N

      ON: Shift lever in P or N

      		 -

      Powertrain > Engine and ECT > Data List
      Tester Display
      Neutral Position SW Signal
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

  4. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY


    1. Inspect the park/neutral position switch assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - PARK/NEUTRAL POSITION SWITCH ASSEMBLY)


    1. Disconnect the G126 engine stop and start ECU connector.

    2. Disconnect the C24 park/neutral position switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G126-21 (STA) - C24-5 (L) Always Below 1 Ω
      G126-17 (CLL) - C24-4 (B) Always Below 1 Ω
      G126-21 (STA) - Body ground Always 80 to 180 Ω
      G126-17 (CLL) - Body ground Always 10 kΩ or higher
      C24-5 (L) - Body ground Always 80 to 180 Ω
      C24-4 (B) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE STOP AND START ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY


    1. Inspect the park/neutral position switch assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (ECM - PARK/NEUTRAL POSITION SWITCH ASSEMBLY)


    1. Disconnect the G85 and C57 ECM connectors.

    2. Disconnect the C24 park/neutral position switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C57-12 (P) - C24-6 (PL) Always Below 1 Ω
      C57-15 (R) - C24-1 (RL) Always Below 1 Ω
      C57-13 (N) - C24-9 (NL) Always Below 1 Ω
      C57-14 (D) - C24-7 (DL) Always Below 1 Ω
      G85-11 (NSW) - C24-4 (B) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  8. 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 here

    NG

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


    1. Disconnect the G126 engine stop and start ECU connector.

    2. Disconnect the C105 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
      G126-26 (TMVC) - C105-1 (W1) Always Below 1 Ω
      G126-25 (TME2) - C105-3 (F+) Always Below 1 Ω
      G126-8 (TMN) - C105-2 (TMN) Always Below 1 Ω
      G126-26 (TMVC) - Body ground Always 10 kΩ or higher
      C105-1 (W1) - Body ground Always 10 kΩ or higher
      G126-25 (TME2) - Body ground Always 10 kΩ or higher
      C105-3 (F+) - Body ground Always 10 kΩ or higher
      G126-8 (TMN) - Body ground Always 10 kΩ or higher
      C105-2 (TMN) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    B0024ANC99
    *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
      G126-8 (TMN) - G126-25 (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 SENSOR (NEUTRAL POSITION SWITCH) for 4WD: Click here for 2WD: Click here