SFI SYSTEM(w/o Canister Pump Module), Diagnostic DTC:P003012, P003013, P101A9E

DTC Code DTC Name
P003012 HO2S Heater Control Bank 1 Sensor 1 Circuit Short to Battery
P003013 HO2S Heater Control Bank 1 Sensor 1 Circuit Open
P101A9E A/F Sensor Heater Performance Bank 1 Sensor 1 Stuck On

DESCRIPTION

The air fuel ratio sensor (sensor 1) generates current that corresponds to the actual air fuel ratio. This sensor current is used to provide the ECM with feedback so that it can control the air fuel ratio. The ECM determines the deviation from the stoichiometric air fuel ratio level, and regulates the fuel injection duration. If the air fuel ratio sensor (sensor 1) malfunctions, the ECM is unable to control the air fuel ratio accurately.

The air fuel ratio sensor (sensor 1) is a planar type sensor and integrated with the heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are a narrow type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, therefore sensor activation is accelerated.

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a three-way catalytic converter is used. For the most efficient use of the three-way catalytic converter, the air fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

B00883UE01

Tech Tips


  • When any of these DTCs are stored, the ECM enters fail-safe mode. The ECM turns off the air fuel ratio sensor (sensor 1) heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off.

  • Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor (sensor 1).

  • The ECM has a pulse width modulated control circuit to adjust the current through the heater. The air fuel ratio sensor (sensor 1) heater circuit uses a relay on the +B side of the circuit.

    B0087TGE01
DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory Note
P003012 HO2S Heater Control Bank 1 Sensor 1 Circuit Short to Battery The air fuel ratio sensor (sensor 1) heater current is more than the specified value while the heater is operating (1 trip detection logic).
  • Short in air fuel ratio sensor (sensor 1) heater circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

Comes on DTC stored SAE Code: P0032
P003013 HO2S Heater Control Bank 1 Sensor 1 Circuit Open The air fuel ratio sensor (sensor 1) heater current is less than the specified value while the heater is operating (1 trip detection logic).
  • Open or short in air fuel ratio sensor (sensor 1) heater circuit

  • Air fuel ratio sensor (sensor 1)

  • EFI-MAIN NO. 2 relay

  • ECM

Comes on DTC stored SAE Code: P0031
P101A9E A/F Sensor Heater Performance Bank 1 Sensor 1 Stuck On The air fuel ratio sensor (sensor 1) heater voltage level is low while the heater is not operating (1 trip detection logic).
  • Short in air fuel ratio sensor (sensor 1) heater circuit

  • Air fuel ratio sensor (sensor 1)

  • ECM

Comes on DTC stored SAE Code: P101D

MONITOR DESCRIPTION

The ECM uses information from the air fuel ratio sensor (sensor 1) to regulate the air fuel ratio and keep it close to the stoichiometric level. This maximizes the ability of the three-way catalytic converter to purify the exhaust gases.

The air fuel ratio sensor (sensor 1) detects oxygen levels in the exhaust gas and transmits the information to the ECM. The inner surface of the sensor element is exposed to the outside air. The outer surface of the sensor element is exposed to the exhaust gas. The sensor element is made of platinum-coated zirconia and includes an integrated heating element.

The zirconia element generates a small voltage when there is a large difference in the oxygen concentrations between the exhaust gas and outside air. The platinum coating amplifies this voltage generation.

The air fuel ratio sensor (sensor 1) is more efficient when heated. When the exhaust gas temperature is low, the sensor cannot generate useful current signals without supplementary heating. The ECM regulates the supplementary heating using a duty-cycle approach to adjust the average current in the sensor heater element. If the heater current is outside the normal range, the signal transmitted by the air fuel ratio sensor (sensor 1) becomes inaccurate. As a result, the ECM is unable to regulate the air fuel ratio properly.

When the current in the air fuel ratio sensor (sensor 1) heater is outside the normal operating range, the ECM interprets this as a malfunction in the sensor heater and stores a DTC.

MONITOR STRATEGY

Frequency of Operation Continuous

TYPICAL ENABLING CONDITIONS

P003013
Output duty cycle 30% or higher
P003012
Output duty cycle 10% or higher
P101A9E
Output duty cycle Less than 75%

CONFIRMATION DRIVING PATTERN

B0084W6E51

  1. Connect the GTS to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the GTS on.

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

  5. Turn the ignition switch off and wait for at least 30 seconds.

  6. Turn the ignition switch to ON [A].

  7. Turn the GTS on.

  8. Start the engine and idle it for 5 minutes or more [B].

  9. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of 3000 rpm for 1 minute [C].

  10. Idle the engine for 5 minutes or more [D].

  11. Enter the following menus: Powertrain / Engine / Trouble Codes [E].

  12. Read the pending DTCs.

    Tech Tips


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

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

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

  14. Input the DTC: P003012, P003013 or P101A9E.

  15. Check the DTC judgment result.

    GTS 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

    Tech Tips


    • If the judgment result is NORMAL, the system is normal.

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

    • If the judgment result is INCOMPLETE, perform steps [B] through [E] again.

WIRING DIAGRAM

B0085FQE05

CAUTION / NOTICE / HINT

Note

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

Tech Tips


  • Refer to "Data List / Active Test" [A/F (O2) Sensor Heater Duty Ratio B1S1].

    Click here

  • Sensor 1 refers to the sensor closest to the engine assembly.

  • Sensor 2 refers to the sensor farthest away from the engine assembly.

  • Change the fuel injection volume using the Control the Injection Volume for A/F Sensor function provided in the Active Test and monitor the air fuel ratio sensor (sensor 1) output current Click here. If the sensor output current does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

  • Read Freeze Frame Data using the GTS. 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.

PROCEDURE


  1. INSPECT AIR FUEL RATIO SENSOR (SENSOR 1) (HEATER RESISTANCE)


    1. Inspect the air fuel ratio sensor (sensor 1).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

      Click here

      Result
      Proceed to
      OK
      NG

    NG
    OK
  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF AIR FUEL RATIO SENSOR (SENSOR 1))

    B0088FDC01
    *a

    Front view of wire harness connector

    (to Air Fuel Ratio Sensor (Sensor 1))


    1. Disconnect the air fuel ratio sensor (sensor 1) connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      C50-2 (+B) - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR (SENSOR 1) - ECM)


    1. Disconnect the air fuel ratio sensor (sensor 1) 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
      C50-1 (HA1A) - C57-9 (HA1A) Always Below 1 Ω
      C50-1 (HA1A) or C57-9 (HA1A) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
    5. Turn the ignition switch off and wait for at least 30 seconds.

      Result
      Proceed to
      NEXT

    NEXT
  5. CHECK WHETHER DTC OUTPUT RECURS (DTC P003012, P003013 AND/OR P101A9E)


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

    2. Enter the following menus: Powertrain / Engine / Trouble Codes.

    3. Read the DTCs.


      Powertrain > Engine > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output A
      DTC P003012, P003013 and/or P101A9E is output B

    A
    B
  6. INSPECT EFI-MAIN NO. 2 RELAY


    1. Inspect the EFI-MAIN NO. 2 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG
    OK
  7. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 2 RELAY)

    B0088DIC01
    *1 Engine Room Relay Block and Junction Block Assembly
    *2 EFI-MAIN NO. 2 Relay

    1. Remove the EFI-MAIN NO. 2 relay from the engine room relay block and junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (EFI-MAIN NO. 2 relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG
    OK
  8. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - BODY GROUND)


    1. Remove the EFI-MAIN NO. 2 relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (EFI-MAIN NO. 2 relay) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  9. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - AIR FUEL RATIO SENSOR (SENSOR 1))


    1. Remove the EFI-MAIN NO. 2 relay from the engine room relay block and junction block assembly.

    2. Disconnect the air fuel ratio sensor (sensor 1) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      5 (EFI-MAIN NO. 2 relay) - C50-2 (+B) Always Below 1 Ω
      5 (EFI-MAIN NO. 2 relay) or C50-2 (+B) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK
    NG