SFI SYSTEM (w/ EGR System), Diagnostic DTC:P0171, P0172, P0174, P0175

DTC Code DTC Name
P0171 System Too Lean (Bank 1)
P0172 System Too Rich (Bank 1)
P0174 System Too Lean (Bank 2)
P0175 System Too Rich (Bank 2)

DESCRIPTION

The fuel trim is related to the feedback compensation value, not to the basic injection duration. The fuel trim consists of both the short-term and long-term fuel trim.

The short-term fuel trim is fuel compensation that is used to constantly maintain the air fuel ratio at stoichiometric levels. The signal from the air fuel ratio sensor indicates whether the air fuel ratio is rich or lean compared to the stoichiometric ratio. This triggers a reduction in the fuel injection volume if the air fuel ratio is rich and an increase in the fuel injection volume if it is lean.

Factors such as individual engine differences, wear over time and changes in operating environment cause short-term fuel trim to vary from the central value. The long-term fuel trim, which controls overall fuel compensation, compensates for long-term deviations in the fuel trim from the central value caused by the short-term fuel trim compensation.

If both the short-term and long-term fuel trim are lean or rich beyond predetermined values, it is interpreted as a malfunction, and the ECM illuminates the MIL and sets a DTC.

DTC No. DTC Detection Condition Trouble Area

P0171

P0174

With warm engine and stable air fuel ratio feedback, fuel trim considerably in error to lean side (2 trip detection logic)
  • Intake system

  • Fuel injector assembly

  • Mass air flow meter sub-assembly

  • Engine coolant temperature sensor

  • Fuel pressure

  • Gas leaks from exhaust system

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • Air fuel ratio sensor heater (bank 1, 2 sensor 1)

  • A/F relay

  • A/F fuse

  • Air fuel ratio sensor heater (bank 1, 2 sensor 1) circuit

  • PCV valve and hose

  • PCV hose connections

  • EGR valve assembly

  • ECM

P0172

P0175

With warm engine and stable air fuel ratio feedback, fuel trim considerably in error to rich side (2 trip detection logic)
  • Fuel injector assembly

  • Mass air flow meter sub-assembly

  • Engine coolant temperature sensor

  • Ignition system

  • Fuel pressure

  • Gas leaks from exhaust system

  • Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • Air fuel ratio sensor heater (bank 1, 2 sensor 1)

  • A/F relay

  • A/F fuse

  • Air fuel ratio sensor heater (bank 1, 2 sensor 1) circuit

  • EGR valve assembly

  • ECM

Tech Tips


  • When DTC P0171 or P0174 is set, the actual air fuel ratio is on the lean side. When DTC P0172 or P0175 is set, the actual air fuel ratio is on the rich side.

  • If the vehicle runs out of fuel, the air fuel ratio is lean and DTC P0171 or P0174 may be set. The MIL is then illuminated.

  • When the total of the short-term and long-term fuel trim values is within the malfunction threshold (and the engine coolant temperature is more than 75°C (167°F)), the system is functioning normally.

MONITOR DESCRIPTION

Under closed-loop fuel control, fuel injection volumes that deviate from those estimated by the ECM cause changes in the long-term fuel trim compensation value. The long-term fuel trim is adjusted when there are persistent deviations in the short-term fuel trim values. Deviations from the ECM's estimated fuel injection volumes also affect the average fuel trim learning value, which is a combination of the average short-term fuel trim (fuel feedback compensation value) and the average long-term fuel trim (learning value of the air fuel ratio). If the average fuel trim learning value exceeds the malfunction thresholds, the ECM interprets this as a fault in the fuel system and sets a DTC.


CONFIRMATION DRIVING PATTERN

A01NGNGE20

  1. Connect the intelligent tester to the DLC3.

  2. Turn the power switch on (IG) and turn the tester on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Click here.

  4. Turn the power switch off.

  5. Turn the power switch on (IG) and turn the tester on [A].

  6. Put the engine in inspection mode Click here.

  7. Start the engine and warm it up (until the engine coolant temperature is 75°C (167°F) or more) with all the accessories switched off [B].

  8. With the engine warmed up, idle the engine for 2 minutes or more [C].

  9. Drive the vehicle at between 60 and 120 km/h (37 and 75 mph) and at an engine speed of between 1400 rpm and 2500 rpm for 5 minutes or more [D].

  10. Enter the following menus: Powertrain / Engine and ECT / DTC / Pending [E].

  11. Read the pending DTC.

  12. If a pending DTC is output, the system is malfunctioning.

    Tech Tips

    If a pending DTC is not output, perform the following procedure.

  13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  14. Input the DTC: P0171, P0172, P0174 or P0175.

  15. Check the DTC judgment result.

    Tester Display Description
    NORMAL
    • DTC judgment completed

    • System normal

    ABNORMAL
    • DTC judgment completed

    • System abnormal

    INCOMPLETE
    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions

    UNKNOWN
    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    Tech Tips


    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [C] through [D] and check the DTC judgment result again.

WIRING DIAGRAM

Refer to DTC P2195 Click here.

INSPECTION PROCEDURE

Tech Tips

Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor in the Active Test. The Control the Injection Volume for A/F Sensor function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the intelligent tester.


  1. Connect the intelligent tester to the DLC3.

  2. Turn the power switch on (IG).

  3. Turn the tester on.

  4. Put the engine in inspection mode Click here.

  5. Start the engine.

  6. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.

  7. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.

  8. Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).

  9. Monitor the voltage outputs of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the tester.

    Tech Tips


    • The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.

    • Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

    Tester Display (Sensor) Injection Volume Status Voltage

    AFS Voltage B1S1 or AFS Voltage B2S1

    (Air fuel ratio)

    +25% Rich Less than 3.1 V

    AFS Voltage B1S1 or AFS Voltage B2S1

    (Air fuel ratio)

    -12.5% Lean More than 3.4 V

    O2S B1S2 or O2S B2S2

    (Heated oxygen)

    +25% Rich More than 0.55 V

    O2S B1S2 or O2S B2S2

    (Heated oxygen)

    -12.5% Lean Less than 0.4 V

    Note

    The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

    Case

    Air Fuel Ratio Sensor (Sensor 1)

    Output Voltage

    Heated Oxygen Sensor (Sensor 2)

    Output Voltage

    Main Suspected Trouble Area
    1 A01NFFXE12 A01NH0JE12 -
    2 A01NE6JE06 A01NH0JE12
    • Air fuel ratio sensor

    • Air fuel ratio sensor heater

    • Air fuel ratio sensor circuit

    3 A01NFFXE12 A01NE6JE07
    • Heated oxygen sensor

    • Heated oxygen sensor heater

    • Heated oxygen sensor circuit

    • Exhaust gas leaks

    4 A01NE6JE06 A01NE6JE06
    • Fuel pressure

    • Exhaust gas leaks

      (Air fuel ratio extremely lean or rich)


    • Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.

    • To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / All Data / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

      Note

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

      Tech Tips


      • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

      • A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.

      • A high air fuel ratio sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0171, P0172, P0174 OR P0175)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / DTC.

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P0171, P0172, P0174 and/or P0175 are output A
      DTC P0171, P0172, P0174 or P0175 and other DTCs are output B

      Tech Tips

      If any DTCs other than P0171, P0172, P0174 or P0175 are output, troubleshoot those DTCs first.


    B
    A
  2. CHECK PCV HOSE (HOSE CONNECTIONS)


    1. Check the PCV hose connections Click here.

      OK
      PCV hose is connected correctly and is not damaged.

    NG
    OK
  3. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leaks Click here.

      OK
      No leaks in intake system.

    NG
    OK
  4. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (AIR FUEL RATIO CONTROL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Put the engine in inspection mode Click here.

    5. Start the engine.

    6. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.

    7. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.

    8. Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).

    9. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the tester.

      Tech Tips


      • The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.

      • Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

      • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has maximum output delay of approximately 20 seconds.

      Tester Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1 or AFS Voltage B2S1

      (Air fuel ratio)

      +25% Rich Less than 3.1 V

      AFS Voltage B1S1 or AFS Voltage B2S1

      (Air fuel ratio)

      -12.5% Lean More than 3.4 V

      O2S B1S2 or O2S B2S2

      (Heated oxygen)

      +25% Rich More than 0.55 V

      O2S B1S2 or O2S B2S2

      (Heated oxygen)

      -12.5% Lean Less than 0.4 V
      Result
      Status AFS Voltage B1S1 or AFS Voltage B2S1 Status O2S B1S2 or O2S B2S2 Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition Misfire Suspected Trouble Area Proceed to
      Lean/Rich Lean/Rich Normal - - A
      Lean Lean Actual air fuel ratio lean May occur
      • PCV valve and hose

      • PCV hose connections

      • Fuel injector assembly blockage

      • Gas leaks from exhaust system

      • Intake system

      • Fuel pressure

      • Mass air flow meter sub-assembly

      • Engine coolant temperature sensor

      • EGR valve assembly

      A
      Rich Rich Actual air fuel ratio rich -
      • Fuel injector assembly leakage or blockage

      • Gas leaks from exhaust system

      • Ignition system

      • Fuel pressure

      • Mass air flow meter sub-assembly

      • Engine coolant temperature sensor

      A
      Lean Lean/Rich Air fuel ratio sensor malfunction -
      • Air fuel ratio sensor

      • EGR valve assembly

      B
      Rich Lean/Rich Air fuel ratio sensor malfunction - Air fuel ratio sensor B

      Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor output voltage (AFS Voltage) is consistently more than 3.4 V, and the heated oxygen sensor output voltage (O2S) is consistently less than 0.4 V.

      Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage is consistently less than 3.1 V, and the O2S is consistently more than 0.55 V.

      Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output voltage of the heated oxygen sensor alternates correctly.


    B
    A
  5. READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.

    5. Read the Data List twice, when the engine is both cold and warmed up.

      Standard
      With cold engine
      Same as ambient air temperature.
      With warm engine
      Between 75°C and 95°C (167°F and 203°F)

    NG
    OK
  6. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY


    1. Inspect the mass air flow meter sub-assembly Click here.


    NG
    OK
  7. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG
    OK
  8. INSPECT FOR EXHAUST GAS LEAK


    1. Inspect for exhaust gas leaks from the exhaust manifold sub-assembly and exhaust pipes.

      OK
      No gas leaks

    NG
    OK
  9. CHECK IGNITION SYSTEM


    1. Check the ignition system Click here.


    NG
    OK
  10. INSPECT FUEL INJECTOR ASSEMBLY (INJECTION VOLUME)


    1. Inspect the fuel injector assembly Click here.


    OK
    NG
  11. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. Inspect the air fuel ratio sensor Click here.


    NG
    OK
  12. CHECK TERMINAL VOLTAGE (+B TERMINAL OF AIR FUEL RATIO SENSOR)


    1. A01NDLWE11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Air Fuel Ratio Sensor)

      *2 Bank 1
      *3 Bank 2

      Disconnect the air fuel ratio sensor connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      D20-2 (+B) - Body ground Power switch on (IG) 11 to 14 V
      D19-2 (+B) - Body ground Power switch on (IG) 11 to 14 V
    4. Reconnect the air fuel ratio sensor connector.


    NG
    OK
  13. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)


    1. Disconnect the air fuel ratio sensor connector.

      A01NCUUE04
    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      D20-1 (HA1A) - D1-24 (HA1A) Always Below 1 Ω
      D20-3 (A1A+) - D1-100 (A1A+) Always Below 1 Ω
      D20-4 (A1A-) - D1-132 (A1A-) Always Below 1 Ω
      D19-1 (HA2A) - D1-22 (HA2A) Always Below 1 Ω
      D19-3 (A2A+) - D1-99 (A2A+) Always Below 1 Ω
      D19-4 (A2A-) - D1-131 (A2A-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D20-1 (HA1A) or D1-24 (HA1A) - Body ground Always 10 kΩ or higher
      D20-3 (A1A+) or D1-100 (A1A+) - Body ground Always 10 kΩ or higher
      D20-4 (A1A-) or D1-132 (A1A-) - Body ground Always 10 kΩ or higher
      D19-1 (HA2A) or D1-22 (HA2A) - Body ground Always 10 kΩ or higher
      D19-3 (A2A+) or D1-99 (A2A+) - Body ground Always 10 kΩ or higher
      D19-4 (A2A-) or D1-131 (A2A-) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Air Fuel Ratio Sensor)

      *2

      Front view of wire harness connector

      (to ECM)

      *3 Bank 1 *4 Bank 2
    4. Reconnect the ECM connector.

    5. Reconnect the air fuel ratio sensor connector.


    NG
    OK
  14. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT
  15. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the power switch off.

    6. Turn the power switch on (IG) and turn the tester on.

    7. Put the engine in inspection mode Click here.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    11. Input the DTC: P0171, P0172, P0174 or P0175.

    12. Check the STATUS is NORMAL. If STATUS is INCOMPLETE, perform the driving pattern adding the vehicle speed.

      Result
      Result Proceed to
      ABNORMAL (DTC P0171, P0172, P0174 or P0175 is output) A
      NORMAL (DTC is not output) B

    B
    A
  16. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

    5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.

    7. Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.

      Note


      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.

      • Be sure to return the EGR valve to step 0 when the Active Test is completed.

      • Do not open the EGR valve 30 steps or more during the Active Test.

      OK
      MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.
      Standard
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps

      MAP

      (Data List)

      (EGR valve is fully closed) MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      Tech Tips


      • While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.

      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.

      Result
      Result Proceed to
      Outside of standard range A
      Within standard range B

    B
    A
  17. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly Click here.

    2. Check if the EGR valve is stuck open.

      OK
      EGR valve is tightly closed.
    3. Reinstall the EGR valve assembly Click here.


    NG
    OK
  18. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT
  19. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTC Click here.

    5. Turn the power switch off.

    6. Turn the power switch on (IG) and turn the tester on.

    7. Put the engine in inspection mode Click here.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    11. Input the DTC: P0171, P0172, P0174 or P0175.

    12. Check the DTC judgment result.


    NEXT
  20. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the air fuel ratio sensor connector.

      A01NHWLE03
    2. Remove the engine room junction block assembly.

    3. Disconnect the engine room junction block assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      D20-2 (+B) - 3C-2 (Engine room junction block assembly) Always Below 1 Ω
      D19-2 (+B) - 3C-2 (Engine room junction block assembly) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D20-2 (+B) or 3C-2 (Engine room junction block assembly) - Body ground Always 10 kΩ or higher
      D19-2 (+B) or 3C-2 (Engine room junction block assembly) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Air Fuel Ratio Sensor)

      *2 Bank 1
      *3 Bank 2 *4 Engine Room Junction Block Assembly
      *5

      Front view of wire harness connector

      (to Engine Room Junction Block Assembly)

      - -
    5. Reconnect the engine room junction block assembly connector.

    6. Reinstall the engine room junction block assembly.

    7. Reconnect the air fuel ratio sensor connector.


    NG
    OK
  21. CHECK TERMINAL VOLTAGE (ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. A01NH5QE05
      Text in Illustration
      *1 Engine Room Junction Block Assembly
      *2

      Front view of wire harness connector

      (to Engine Room Junction Block Assembly)

      Remove the engine room junction block assembly.

    2. Disconnect the engine room junction block assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3A-1 (Engine room junction block assembly) - Body ground Always 11 to 14 V
    4. Reconnect the engine room junction block assembly connector.

    5. Reinstall the engine room junction block assembly.


    NG
    OK
  22. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - EFI MAIN RELAY)


    1. Remove the engine room junction block assembly.

      A01NEKAE04
    2. Disconnect the engine room junction block assembly connector.

    3. Remove the EFI MAIN relay from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      3C-7 (Engine room junction block assembly) - EFI MAIN relay terminal 3 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      3C-7 (Engine room junction block assembly) or EFI MAIN relay terminal 3 - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1 Engine Room Junction Block Assembly *2

      Front view of wire harness connector

      (to Engine Room Junction Block Assembly)

      *3 Engine Room Relay Block - -
    5. Reinstall the EFI MAIN relay.

    6. Reconnect the engine room junction block assembly connector.

    7. Reinstall the engine room junction block assembly.


    NG
    OK
  23. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - BODY GROUND)


    1. Remove the engine room junction block assembly.

      A01NFYWE02
    2. Disconnect the engine room junction block assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      3C-17 (Engine room junction block assembly) - Body ground Always Below 1 Ω
      Text in Illustration
      *1 Engine Room Junction Block Assembly *2

      Front view of wire harness connector

      (to Engine Room Junction Block Assembly)

    4. Reconnect the engine room junction block assembly connector.

    5. Reinstall the engine room junction block assembly.


    NG
    OK