СИСТЕМА ECD, Diagnostic DTC:P1166

DTC Code DTC Name
P1166 Oxygen Concentration Implausibly Low (in Overrun Mode)

DESCRIPTION

Refer to P0030 Click here.

DTC No. DTC Detection Condition Trouble Area
P1166

Oxygen concentration lower than estimated concentration for specified condition

(3 trip detection logic)

  • Injector assembly

  • EGR valve assembly

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • ECM

WIRING DIAGRAM

Refer to P0201 Click here.

A01IN77E01

INSPECTION PROCEDURE

Note


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

  • After replacing the air fuel ratio sensor, the ECM needs initialization Click here.

  • After replacing the EGR valve assembly, the ECM needs initialization Click here.

  • After replacing the injector assembly, the ECM needs Registration and Initialization Click here.

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

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. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1166)


    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 / Trouble Codes.

    4. Read DTCs.

      Result
      Result Proceed to
      DTC P1166 A
      DTC P1166 and other DTCs B

      Tech Tips


      • If any DTCs other than P1166 are output, troubleshoot those DTCs first.

      • If a DTC is stored for the heater system of the air fuel ratio sensor, first repair the heater system.


    B

    GO TO DTC CHART Click here

    A

  2. INSPECT INJECTOR ASSEMBLY


    1. Disconnect the injector assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 Always 0.3 to 0.7 Ω

    NG

    REPLACE INJECTOR ASSEMBLY OF MALFUNCTIONING CYLINDER Click here

    OK

  3. CHECK FOR EGR SYSTEM DTCS


    1. Check for EGR system DTCs.

      OK
      No EGR system DTCs are stored.

    NG

    CHECK AND TROUBLESHOOT EGR SYSTEM DTCS Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)


    1. Disconnect the air fuel ratio sensor 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
      C77-1 (AF1+) - C84-127 (AF1+) Always Below 1 Ω
      C77-2 (AF1-) - C84-126 (AF1-) Always Below 1 Ω
      C77-3 (HAF1) - C84-46 (HAF1) Always Below 1 Ω
      C77-5 (TR1) - C84-128 (TR1) Always Below 1 Ω
      C77-6 (RE1) - C84-125 (RE1) Always Below 1 Ω
      C77-1 (AF1+) or C84-127 (AF1+) - Body ground Always 10 kΩ or higher
      C77-2 (AF1-) or C84-126 (AF1-) - Body ground Always 10 kΩ or higher
      C77-3 (HAF1) or C84-46 (HAF1) - Body ground Always 10 kΩ or higher
      C77-5 (TR1) or C84-128 (TR1) - Body ground Always 10 kΩ or higher
      C77-6 (RE1) or C84-125 (RE1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  5. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.

    2. Perform the O2 sensor learning value reset Click here.


    NEXT

  6. CHECK WHETHER DTC OUTPUT RECURS (DTC P1166)


    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: Engine and ECT / Trouble Codes.

    8. Read the DTCs.

      Result
      Result Proceed to
      No DTC output A
      DTC P1166 B

    B

    REPLACE ECM Click here

    A

    END

  7. REPLACE INJECTOR ASSEMBLY OF MALFUNCTIONING CYLINDER


    1. Replace the injector assembly of the malfunctioning cylinder Click here.

    2. Register the injector compensation code Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  8. CHECK AND TROUBLESHOOT EGR SYSTEM DTCS


    1. Check and perform troubleshooting for EGR system DTCs.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  9. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  10. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  11. 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: Engine and ECT / Trouble Codes.

    8. Confirm that the DTC is not output again.


    NEXT

    END