SFI SYSTEM, Diagnostic DTC:P003012,P003013 and 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 a voltage* that corresponds to the actual air fuel ratio. This sensor voltage 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 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.

*: Value changes inside the ECM. Since the air fuel ratio sensor (sensor 1) is a current output element, the current is converted into a voltage inside the ECM. Any measurements taken at the air fuel ratio sensor (sensor 1) or ECM connectors will show a constant voltage.

A363544E05
Tip:

  • 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.

    A355617E04

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P003012

HO2S Heater Control Bank 1 Sensor 1 Circuit Short to Battery

Air fuel ratio sensor (sensor 1) heater current reaches the high limit (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

Air fuel ratio sensor (sensor 1) heater current is less than 0.8 A, even when the air fuel ratio sensor (sensor 1) heater duty cycle is 30% or higher (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

Air fuel ratio sensor (sensor 1) heater current is higher than the specified value while the heater is not operating (1 trip detection logic).

  • Short in air fuel ratio sensor (sensor 1) heater circuit

  • 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 voltage 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

Table 1. P003012:

Heater output duty cycle

Higher than 0%
Table 2. P003013:

Heater output duty cycle

30% or higher
Table 3. P101A9E:

Heater output duty cycle

Less than 60%

CONFIRMATION DRIVING PATTERN

A262623E02

  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.

    Tip:

    • 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

    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    Tip:

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

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

    • If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [E] again.

WIRING DIAGRAM

A357472E05

CAUTION / NOTICE / HINT

Note:

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

Tip:

  • 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 output voltage (Click here). If the sensor output voltage 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

      Tip:

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

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE AIR FUEL RATIO SENSOR (SENSOR 1)

    Click here

    OK

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

    A217280C65

    *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

      B89-2 (+B) - Body ground

      Ignition switch ON

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - AIR FUEL RATIO SENSOR (SENSOR 1))Click here

    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

      B89-1 (HA1A) - B208-19 (HA1A)

      Always

      Below 1 Ω

      B89-1 (HA1A) or B208-19 (HA1A) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P003012, P003013 OR P101A9E)

    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.

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

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

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

    10. Read the DTCs.

      Powertrain > Engine > Trouble Codes

      Result

      Result

      Proceed to

      DTCs are not output

      A

      DTC P003012, P003013 or P101A9E is output

      B
    A

    CHECK FOR INTERMITTENT PROBLEMS

    Click here

    B

    REPLACE ECM

    Click here

  5. 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

      3 (EFI-MAIN NO. 2 relay) - B89-2 (+B)

      Always

      Below 1 Ω

      3 (EFI-MAIN NO. 2 relay) or B89-2 (+B) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT RELAY (EFI-MAIN NO. 2 RELAY)

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

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE RELAY (EFI-MAIN NO. 2 RELAY)

    OK

  7. CHECK TERMINAL VOLTAGE (POWER SOURCE OF 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

      5 (EFI-MAIN NO. 2 relay) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI-MAIN NO. 2 RELAY)

    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

      2 (EFI-MAIN NO. 2 relay) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN RELAY - EFI-MAIN NO. 2 RELAY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR