STOP AND START SYSTEM, Diagnostic DTC:P1780

DTC Code DTC Name
P1780 Park / Neutral Position Switch Malfunction

DESCRIPTION

The engine stop and start ECU detects a malfunction by comparing the shift position signal with the park/neutral position switch assembly input state. When a malfunction occurs, the engine stop and start ECU stores P1780, the stop and start cancel indicator light blinks , and stops the stop and start system control.

DTC No. Freeze Frame Data * DTC Detection Condition Trouble Area
P1780 Neutral switch malfunction (stuck ON)

Either of the following condition continues for 2 seconds or more (2 trip detection logic):


  • The park/neutral position switch signal is on and no starter input exists with the shift lever in D.

  • The park/neutral position switch signal is on and no starter input exists with the shift lever in R.

  • Park/neutral position switch assembly

  • Engine stop and start ECU

  • ECM

  • Harness or connector
Neutral switch malfunction (stuck OFF)

The following condition continues for 15 seconds or more (2 trip detection logic):


  • The park/neutral position switch signal is off and no starter output exists with the shift lever in P or N.

  • Park/neutral position switch assembly

  • Engine stop and start ECU

  • ECM

  • Harness or connector

*: Since each piece of information can be confirmed by freeze frame data, record the freeze frame data before deleting the diagnosis code.

WIRING DIAGRAM

A005LVOE04

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 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, perform deceleration sensor zero point clear and calibration Click here.

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

PROCEDURE


  1. READ VALUE USING GTS (PARK/NEUTRAL POSITION SWITCH SIGNAL)


    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.

      Tester Display Measurement Item / Range Normal Condition Diagnostic Note
      Shift SW Status (P Range)

      PNP switch status /

      ON or OFF

      ON: Shift lever in P

      OFF: Shift lever not in P

      		 -
      Shift SW Status (R Range)

      PNP switch status /

      ON or OFF

      ON: Shift lever in R

      OFF: Shift lever not in R

      		 -
      Shift SW Status (N Range)

      PNP switch status /

      ON or OFF

      ON: Shift lever in N

      OFF: Shift lever not in N

      		 -
      Shift SW Status (D Range)

      PNP switch status /

      ON or OFF

      ON: Shift lever in D

      OFF: Shift lever not in D

      		 -
      Result
      Result Proceed to
      Data display is within Normal Condition range A
      Data display is not within Normal Condition range B

    B

    INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    A

  2. READ VALUE USING GTS (PARK/NEUTRAL POSITION SWITCH SIGNAL)


    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.

      Tester Display Measurement Item / Range Normal Condition Diagnostic Note
      Neutral Position SW Signal

      PNP switch status /

      ON or OFF

      ON: Shift lever in P or N

      OFF: Shift lever not in P or N

      		 -
      Result
      Result Proceed to
      Data display is not within Normal Condition range A
      Data display is within Normal Condition range B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  3. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY


    1. Inspect the park/neutral position switch assembly Click here.


    NG

    REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    OK

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


    1. Disconnect the A73 engine stop and start ECU connector.

    2. Disconnect the B90 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
      A73-21 (STA) - B90-9 (L) Always Below 1 Ω
      A73-28 (CLL) - B90-4 (B) Always Below 1 Ω
      A73-21 (STA) - Body ground Always 80 to 180 Ω
      A73-28 (CLL) - Body ground Always 10 kΩ or higher
      B90-9 (L) - Body ground Always 80 to 180 Ω
      B90-4 (B) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ENGINE STOP AND START ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY


    1. Inspect the park/neutral position switch assembly Click here.


    NG

    REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    OK

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


    1. Disconnect the B90 park/neutral position switch assembly connector.

    2. Disconnect the B23 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B23-99 (P) - B90-3 (PL) Always Below 1 Ω
      B23-79 (R) - B90-2 (RL) Always Below 1 Ω
      B23-97 (N) - B90-8 (NL) Always Below 1 Ω
      B23-81 (D) - B90-7 (DL) Always Below 1 Ω
      B23-98 (B) - B90-5 (2L) Always Below 1 Ω
      B23-63 (NSW) - B90-4 (B) Always Below 1 Ω

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR