DTC    P0031    Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)

DTC    P0032    Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1)

for Preparation Click here


DESCRIPTION

In order to obtain high purification rates for the carbon monoxide (CO) and hydrocarbon (HC) and a high collection/oxidization rate for particulate matter (PM) in the exhaust gas, a CCo + DPF catalytic converter is used. The air fuel ratio sensor is used to compensate for variation in the EGR rate to reduce PM accumulation of the DPF catalytic converter.
The A/F sensor provides an output voltage that is proportional to the air-fuel ratio that it is measuring. The A/F sensor output voltage is used as feedback to allow the ECM to control the A/F mixture. The inner surface of the air fuel ratio sensor element is exposed to outside air. The outer surface of the sensor element is exposed to exhaust gases. 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 of the exhaust and the outside air. The platinum coating amplifies the voltage generation. When heated, the sensor becomes very efficient. If the temperature of the exhaust is low, the sensor will not generate useful voltage signals without supplemental heating. The ECM regulates the supplemental heating by using a duty-cycle approach to regulate the average current in the heater element.

P0031 
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
5 minutes elapsed after engine coolant temperature reaches more than 70°C (158°F)
Ground short or open in air fuel ratio sensor heater circuit for 5 seconds or more
(1 trip detection logic)
  1. Open in air fuel ratio sensor heater circuit
  2. Air fuel ratio sensor
  3. ECM

P0032 
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
5 minutes elapsed after engine coolant temperature reaches more than 70°C (158°F)
Battery short in air fuel ratio sensor heater circuit for 5 seconds or more
(1 trip detection logic)
  1. Short in air fuel ratio sensor heater circuit
  2. Air fuel ratio sensor
  3. ECM

WIRING DIAGRAM


A198993E02


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the ECM and/or air fuel ratio sensor, the ECM needs Registration and Initialization (Click here).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:
  1. When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the intelligent tester. Then after installing the new ECM, perform all of the initializations/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.
  2. Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

1.INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    A200331E01

  1. Disconnect the air fuel ratio sensor connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2 (+B) - 5 (H-)
    		20°C
    		2.0 to 5.0 Ω

    Text in Illustration 
    *1
    		Component without harness connected
    (Air Fuel Ratio Sensor)

  1. Reconnect the air fuel ratio sensor connector.



NG
Go to step 7
OK


2.CHECK HARNESS AND CONNECTOR (POWER SOURCE)


    A199007E01

  1. Disconnect the air fuel ratio sensor connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    B35-2 (+B) - Body ground
    		Ignition switch ON
    		11 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Air Fuel Ratio Sensor)

  1. Reconnect the air fuel ratio sensor connector.



NG
Go to step 5
OK


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


    A200332E01

  1. Disconnect the air fuel ratio sensor connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    B35-5 (H-) - A19-63 (H-)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    B35-5 (H-) or A19-63 (H-) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Air Fuel Ratio Sensor)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the air fuel ratio sensor connector.

  1. Reconnect the ECM connector.



NG
Go to step 8
OK


4.REPLACE ECM

  1. Replace the ECM (Click here).



NEXT
Go to step 9

5.CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - INTEGRATION RELAY)


    A200333E01

  1. Disconnect the air fuel ratio sensor connector.

  1. Disconnect the integration relay connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    B35-2 (+B) - 1F-8
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    B35-2 (+B) or 1F-8 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Air Fuel Ratio Sensor)
    *2
    		Front view of wire harness connector
    (to Integration Relay)

  1. Reconnect the air fuel ratio sensor connector.

  1. Reconnect the integration relay connector.



NG
Go to step 8
OK


6.CHECK ECM POWER SOURCE CIRCUIT

  1. Check the ECM power source circuit (Click here).



NEXT
Go to step 9

7.REPLACE AIR FUEL RATIO SENSOR

  1. Replace the air fuel ratio sensor (Click here).

  1. Perform the A/F Sensor Compensation Reset (Click here).



NEXT
Go to step 9

8.REPAIR OR REPLACE HARNESS OR CONNECTOR

NEXT


9.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

  1. Connect the intelligent tester to the DLC3.

  1. Clear the DTCs (Click here).

  1. Start the engine and warm it up until the engine coolant temperature reaches 70°C or more.

  1. Allow the engine to idle for 5 minutes or more.

  1. Enter the following menus: Powertrain / Engine and ETC / DTC.

  1. Confirm that the DTC is not output again.


NEXT

END