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 are set, 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 power switch is turned off.

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

    A003ST6E02
DTC No. DTC Detection Condition Trouble Area
P0037

The heater current is less the specified value while the heater is operating

(1 trip detection logic)

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

  • Heated oxygen sensor (sensor 2) heater

  • ECM
P0038

The heater current is higher than the specified value while the heater is operating

(1 trip detection logic)

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

  • Heated oxygen sensor (sensor 2) heater

  • ECM
P102D

The heater current is higher than the specified value while the heater is not operating

(1 trip detection logic)

 ECM

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


  • Refer to "Data List / Active Test" [O2 Heater B1S2 and O2 Heater Curr Val B1S2] 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.

  • 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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

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 HEATED OXYGEN SENSOR (POWER SOURCE VOLTAGE)


    1. A003SD7E06
      Text in Illustration
      *a

      Front view of harness connector

      (to Heated Oxygen Sensor (Sensor 2))

      Disconnect the heated oxygen 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
      B24-2 (+B) - Body ground Power switch on (IG) 11 to 14 V

    4. Reconnect the heated oxygen sensor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATED OXYGEN SENSOR - NO. 2 INTEGRATION RELAY)

    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 (Check for Open)
      Tester Connection Condition Specified Condition
      B24-1 (HT1B) - B31-41 (HT1B) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B24-1 (HT1B) or B31-41 (HT1B) - Body ground Always 10 kΩ or higher

    4. Reconnect the heated oxygen sensor connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATED OXYGEN SENSOR - ECM)

    OK

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


    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. Put the engine in inspection mode Click here.

    6. Start the engine and idle for 5 minutes or more.

    7. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of 2500 rpm for 1 minute.

    8. Idle the engine for 5 minutes or more.

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

    10. Read the pending DTCs.

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

    B

    REPLACE ECM Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here