СИСТЕМА ECD, Diagnostic DTC:P1168

DTC Code DTC Name
P1168 Error Heater Lambda Sensor (LSU) Sensor 1 Bank 1

DESCRIPTION

Refer to DTC P0030 Click here.

DTC No. DTC Detection Condition Trouble Area
P1168

Error Heater Lambda sensor (LSU)

(3 trip detection logic)

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Open or short in air fuel ratio sensor heater circuit

  • ECM

WIRING DIAGRAM

A01IN77E01

INSPECTION PROCEDURE

Note


  • When replacing the ECM and/or air fuel ratio sensor, 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 P1168)


    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 P1168 A
      DTC P1168 and other DTCs B

      Tech Tips

      If any DTCs other than P1168 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. A01IN7YE01
      Text in Illustration
      *a

      Component without harness connected

      (Air Fuel Ratio Sensor)

      Disconnect the air fuel ratio sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4 (+B) - 3 (HAF1) 20°C (68°F) 2.0 to 3.2 Ω

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE)


    1. Disconnect the air fuel ratio sensor connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C77-4 (+B) - Body ground Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - EFI MAIN RELAY) 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 P1168)


    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
      DTC P1168 A
      No DTC output B

    B

    END

    A

  7. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  8. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - EFI MAIN RELAY)


    1. Disconnect the air fuel ratio sensor connector.

    2. Remove the EFI MAIN relay from the engine room No. 1 relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C77-4 (+B) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      C77-4 (+B) or 3 (EFI MAIN relay holder) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  9. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  10. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  11. 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

  12. 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