ECD SYSTEM, Diagnostic DTC:P1551

DTC Code DTC Name
P1551 Plausibility Error for Oil Pressure Sensor

DESCRIPTION

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P1551

Plausibility Error for Oil Pressure Sensor

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

Does not come on

DTC stored
Table 1. Related Data List

DTC No.

Data List

P1551

OPSW (Oil Pressure)

WIRING DIAGRAM

A311424E03

CAUTION / NOTICE / HINT

Note:

When replacing the ECM, the ECM needs registration and initialization.

Click here

Tip:

  • 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).

      Powertrain > Engine and ECT > Data List

      Tester Display

      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.

    Tip:

    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.

    Result

    Proceed to

    OK

    NG
    OK

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick 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

      B231-1 (S) - B220-120 (OSW)

      Always

      Below 1 Ω

      B231-1 (S) or B220-120 (OSW) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick 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

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE PART CAUSING OIL PRESSURE DECREASEClick here

    OK

  4. REPLACE ENGINE OIL PRESSURE SWITCH ASSEMBLY

    1. Replace the engine oil pressure switch assembly.

      Click here

    Result

    Proceed to

    NEXT
    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.

      Powertrain > Engine and ECT > Clear DTCs

    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.

      Powertrain > Engine and ECT > Trouble Codes

    8. Read the DTCs.

      Result

      Result

      Result

      Proceed to

      No DTC output

      No DTC output

      A

      DTC P1551

      DTC P1551

      B
    A

    END

    B

  6. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  7. REPAIR OR REPLACE PART CAUSING OIL PRESSURE DECREASE

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

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR

    1. Repair or replace the harness or connector.

    Result

    Proceed to

    NEXT
    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.

      Powertrain > Engine and ECT > Clear DTCs

    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.

      Powertrain > Engine and ECT > Trouble Codes

    8. Confirm that the DTC is not output again.

    Result

    Proceed to

    NEXT
    NEXT

    END