SFI SYSTEM, Diagnostic DTC:P0037, P0038, P102D

DTC Code DTC Name
P0037 Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
P0038 Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2)
P102D O2 Sensor Heater Circuit Performance Bank 1 Sensor 2 Stuck ON

DESCRIPTION

Refer to DTC P0136 Click here.

Tech Tips


  • When any of these DTCs is stored, the ECM enters fail-safe mode. The ECM turns off the heated oxygen sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off.

  • The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The heated oxygen sensor heater circuit uses a relay on the +B side of the circuit.

    A01EL85E04
DTC No. DTC Detection Condition Trouble Area
P0037 The heater current less than the specified value while the heater is operating (1 trip detection logic).

  • Open in heated oxygen sensor (bank 1 sensor 2) heater circuit

  • Heated oxygen sensor (bank 1 sensor 2)

  • EFI MAIN NO. 2 relay

  • ECM
P0038

Heated oxygen sensor heater current reaches high limit

(Hybrid IC high current limiter monitor input "Fail") (1 trip detection logic).

  • Short in heated oxygen sensor (bank 1 sensor 2) heater circuit

  • Heated oxygen sensor (bank 1 sensor 2)

  • EFI MAIN NO. 2 relay

  • ECM
P102D The heater current is higher than the specified value while the heater is not operating (1 trip detection logic). ECM

MONITOR DESCRIPTION

The sensing portion of the heated oxygen sensor has a zirconia element which is used to detect the oxygen concentration in the exhaust gas. If the zirconia element is at the appropriate temperature, and the difference between the oxygen concentrations surrounding the inside and outside surfaces of the sensor is large, the zirconia element generates voltage signals. In order to increase the oxygen concentration detecting capacity of the zirconia element, the ECM supplements the heat from the exhaust with heat from a heating element inside the sensor.

Heated Oxygen Sensor Heater Range Check (P0037, P0038 and P102D):

CONFIRMATION DRIVING PATTERN

A01EMGOE07

  1. Connect the GTS to the DLC3.

  2. Turn the ignition switch to ON and turn the GTS on.

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

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

  5. Turn the ignition switch to ON and turn the GTS on [A].

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

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

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

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

  10. Read 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.

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

  12. Input the DTC: P0037, P0038 or P102D.

  13. 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

    Tech Tips


    • 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

Refer to DTC P0136 Click here.

INSPECTION PROCEDURE

Note

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

Tech Tips


  • 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.

  • 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 function provided in the Active Test and monitor the heated oxygen 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.

PROCEDURE


  1. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)


    1. Inspect the heated oxygen sensor Click here.


    NG

    REPLACE HEATED OXYGEN SENSOR Click here

    OK

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF HEATED OXYGEN SENSOR)


    1. A01EM9RE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Heated Oxygen Sensor)

      Disconnect the heated oxygen sensor 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
      B57-2 (+B) - Body ground Ignition switch ON 11 to 14 V

    NG

    INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (EFI MAIN NO. 2 RELAY) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)


    1. Disconnect the heated oxygen 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
      B57-1 (HT1B) - B58-41 (HT1B) Always Below 1 Ω
      B57-1 (HT1B) or B58-41 (HT1B) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0037, P0038 OR P102D)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

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

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

    7. Read the DTCs.

      Result
      Result Proceed to
      DTC P0037, P0038 or P102D is output A
      DTC is not output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

    REPLACE ECM Click here

  5. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (EFI MAIN NO. 2 RELAY)


    1. Inspect the EFI MAIN NO. 2 relay Click here.


    NG

    REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - EFI MAIN NO. 2 RELAY)


    1. Disconnect the heated oxygen sensor connector.

    2. Remove the engine room junction block assembly from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B57-2 (+B) - 1F-9 Always Below 1 Ω
      B57-2 (+B) or 1F-9 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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