ECD SYSTEM, Diagnostic DTC:P1551

DTC Code DTC Name
P1551 Plausibility Error for Oil Pressure Sensor

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
P1551

When the engine coolant temperature is 24.96°C (76.93°F) or higher with the engine speed 500 rpm or higher, it is detected for 6.5 seconds that the oil pressure condition is the same as that with the engine stopped.

(3 trip detection logic)

  • Oil pressure system

  • Open or short in engine oil pressure switch assembly circuit

  • Engine oil pressure switch assembly

  • ECM
Related Data List
DTC No. Data List
P1551 OPSW (Oil Pressure)

WIRING DIAGRAM

A004P4KE05
*a OSW
*b Engine Oil Pressure Switch Assembly

CAUTION / NOTICE / HINT

Note

When replacing the ECM, the ECM needs Registration and Initialization Click here.

Tech Tips


  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


  1. READ VALUE USING GTS (OPSW (OIL PRESSURE))

    Note


    • Since the engine is stopped due to fail-safe operation when P1551 is detected, clear the DTCs once.

    • If the Active Test cannot be performed, proceed to the inspection in the next step.


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / OPSW (Oil Pressure).

    4. Read the value.

    5. Start the engine and check that the OPSW (Oil Pressure) display changes to OFF.

      OK
      Changes to OFF after the engine starts.

      Tech Tips

      When the ignition switch is turned to ON, the OPSW (Oil Pressure) display normally changes to ON, and then changes to OFF once the engine starts.


    OK

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (ENGINE OIL PRESSURE SWITCH ASSEMBLY - ECM)


    1. Disconnect the engine oil pressure switch assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B98-1 (S) - B91-120 (OSW) Always Below 1 Ω
      B98-1 (S) or B91-120 (OSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  3. CHECK OIL PRESSURE

    Note

    Since the engine is stopped due to fail-safe operation when P1551 is detected, clear the DTCs once.


    1. Check the oil pressure test Click here.


    NG

    REPAIR OR REPLACE PART CAUSING OIL PRESSURE DECREASE Click here

    OK

  4. REPLACE ENGINE OIL PRESSURE SWITCH ASSEMBLY


    1. Replace the engine oil pressure switch assembly Click here.


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC P1551)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs Click here.

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

    7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    8. Read the DTCs.

      Result
      Result Proceed to
      No DTC output A
      DTC P1551 B

    A

    END

    B

    REPLACE ECM Click here

  6. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  7. REPAIR OR REPLACE PART CAUSING OIL PRESSURE DECREASE


    1. Repair the part that is causing the decrease in oil pressure.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  8. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs Click here.

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

    7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    8. Confirm that the DTC is not output again.


    NEXT

    END