ECD SYSTEM, Diagnostic DTC:P2237,P2238,P2239,P2252 and P2253

DTC Code DTC Name
P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)
P2238 Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)
P2239 Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)
P2252 Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1)
P2253 Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1)

DESCRIPTION

Tip:

  • For more information on the air fuel ratio sensor and TOYOTA D-CAT*1, refer to the following procedures (Click here).

  • If P2237, P2238 and/or P2239 is present, refer to the DTC table for TOYOTA D-CAT (Click here).

  • These DTCs are recorded when the A/F sensor has a malfunction, although the title is the oxygen sensor.

    • *1: Diesel Clean Advanced Technology.

The air fuel ratio sensor has the characteristic of providing output voltage which is proportional to the air fuel ratio. The air fuel ratio sensor output voltage*2 is used by the ECM to control the air fuel ratio.

The air fuel ratio sensor is located after the DPNR*3 catalytic converter. This sensor has been developed based on the structure and technology of a sensor that is being used for gasoline engines. The cover portion of the sensor has been changed for use in the diesel engine with TOYOTA D-CAT in order to eliminate the influence of the sensor temperature and particulate matter (PM).

In order to reduce both PM and nitrogen oxides (NOx), the ECM adjusts the air-fuel ratio to slightly rich (but it is lean compared with the stoichiometric air-fuel ratio) based on signals from the air fuel ratio sensor. When the ECM performs PM forced regeneration by adding fuel using the exhaust fuel addition injector, the air-fuel ratio is also properly adjusted using the sensor.

*2: The voltage value changes inside the ECM only.

*3: Diesel Particulate-NOx Reduction system.

A264921E05
Tip:

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

A275096E03

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P2237

Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)

When either of the following conditions is met (1 trip detection logic):

  • Air fuel ratio sensor circuit malfunction

  • The resistance of the air fuel ratio sensor element is 250 Ω or higher for 5 seconds or more.

Main trouble area: Open in air fuel ratio sensor circuit

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater circuit

  • ECM

Comes on

DTC stored

P2238

Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)

Air fuel ratio sensor circuit low (sensor 1)

(1 trip detection logic)

Main trouble area: Open in air fuel ratio sensor circuit

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater circuit

  • ECM

Comes on

DTC stored

P2239

Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)

Air fuel ratio sensor circuit high (sensor 1)

(1 trip detection logic)

Main trouble area: Short in air fuel ratio sensor circuit

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater circuit

  • ECM

Comes on

DTC stored

P2252

Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1)

Air fuel ratio sensor circuit low (sensor 1)

(1 trip detection logic)

Main trouble area: Open in air fuel ratio sensor circuit

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater circuit

  • ECM

Comes on

DTC stored

P2253

Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1)

Air fuel ratio sensor circuit high (sensor 1)

(1 trip detection logic)

Main trouble area: Short in air fuel ratio sensor circuit

  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater circuit

  • ECM

Comes on

DTC stored
Table 1. Related Data List

DTC No.

Data List

P2237

  • AFS Voltage B1S1

  • Exhaust Temperature B1S1

P2238

P2239

P2252

P2253

MONITOR DESCRIPTION

The air fuel ratio sensor outputs a voltage in proportion to the air fuel ratio. If impedance (alternating current resistance) or voltage output of the sensor deviates greatly from the standard range, the ECM interprets this as an open or short malfunction of the air fuel ratio sensor circuit.

CONFIRMATION DRIVING PATTERN

DTC No.

DTC Detection Drive Pattern

P2237

Ignition switch ON for 7 seconds

P2238

P2239

P2252

P2253

WIRING DIAGRAM

A284162E01

CAUTION / NOTICE / HINT

Note:

After replacing the ECM, the new ECM needs registration (Click here) and initialization (Click here).

PROCEDURE

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

    1. Disconnect the air fuel ratio 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

      B8-3 (AF2+) - B76-125 (AF2+)

      Always

      Below 1 Ω

      B8-4 (AF2-) - B76-126 (AF2-)

      Always

      Below 1 Ω

      B8-3 (AF2+) or B76-125 (AF2+) - Body ground

      Always

      10 kΩ or higher

      B8-4 (AF2-) or B76-126 (AF2-) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  2. REPLACE AIR FUEL RATIO SENSOR

    1. Replace the air fuel ratio sensor.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  3. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Warm up the engine.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Clear the DTCs.

      Powertrain > Engine > Clear DTCs

    6. Drive the vehicle

      Tip:

      Make sure that the exhaust gas temperature (Exhaust Temperature B1S1) is 200°C (392°F) or higher.

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

      Powertrain > Engine > Trouble Codes

    8. Confirm that the DTC is not output again.

    Result

    Proceed to

    OK

    NG
    OK

    END

    NG

  4. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  5. REPAIR OR REPLACE HARNESS OR CONNECTOR

    1. Repair or replace the harness or connector.

    Result

    Proceed to

    NEXT
    NEXT

  6. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Warm up the engine.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Clear the DTCs.

      Powertrain > Engine > Clear DTCs

    6. Drive the vehicle at 50 km/h (30 mph) or more for a total of 300 seconds or more.

      Tip:

      Make sure that the exhaust gas temperature (Exhaust Temperature B1S1) is 200°C (392°F) or higher.

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

      Powertrain > Engine > Trouble Codes

    8. Confirm that the DTC is not output again.

    Result

    Proceed to

    NEXT
    NEXT

    END