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DTC    P2237    Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)

DTC    P2238    Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)

DTC    P2239    Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)

DTC    P2252    Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1)

DTC    P2253    Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1)

for Preparation Click here


DESCRIPTION

Refer to DTC P2195 (Click here).

DTC No.
DTC Detection Condition
Trouble Area
P2237
Open in the circuit between terminals A1A+ and A1A- of the air fuel ratio sensor while engine is running
(2 trip detection logic)
  1. Open in air fuel ratio sensor (sensor 1) circuit
  2. Air fuel ratio sensor (sensor 1)
  3. ECM
P2238
Any of the following conditions are met
(2 trip detection logic)
  1. Air fuel ratio sensor output drops while engine is running.
  1. Voltage at terminal A1A+ voltage is 0.5 V or less.
  1. Voltage difference between terminals A1A+ and A1A- voltage is 0.1 V or less.
  1. Open or short in air fuel ratio sensor (sensor 1) circuit
  2. Air fuel ratio sensor (sensor 1)
  3. ECM
P2239
A1A+ voltage is more than 4.5 V
(2 trip detection logic)
  1. Open or short in air fuel ratio sensor (sensor 1) circuit
  2. Air fuel ratio sensor (sensor 1)
  3. ECM
P2252
A1A- voltage is 0.5 V or less
(2 trip detection logic)
  1. Open or short in air fuel ratio sensor (sensor 1) circuit
  2. Air fuel ratio sensor (sensor 1)
  3. ECM
P2253
A1A- voltage is more than 4.5 V
(2 trip detection logic)
  1. Open or short in air fuel ratio sensor (sensor 1) circuit
  2. Air fuel ratio sensor (sensor 1)
  3. ECM

WIRING DIAGRAM

Refer to DTC P2195 (Click here).

INSPECTION PROCEDURE

HINT:
Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor in the Active Test. The Control the Injection Volume for A/F Sensor function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the intelligent tester.
  1. Connect the intelligent tester to the DLC3.
  2. Turn the power switch on (IG) and turn the tester on.
  3. Put the engine in inspection mode (Click here).
  4. Start the engine.
  5. Warm up the engine at 2500 rpm for approximately 90 seconds.
  6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
  7. Perform Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
  8. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the tester.

HINT:
  1. The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
  1. Each sensor reacts in accordance with increases and decreases in the fuel injection volume.


Tester Display
(Sensor)
Injection Volume
Status
Voltage
AFS Voltage B1S1
(Air fuel ratio)
+25%
Rich
Less than 3.1 V
AFS Voltage B1S1
(Air fuel ratio)
-12.5%
Lean
More than 3.4 V
O2S B1S2
(Heated oxygen)
+25%
Rich
 More than 0.55 V
O2S B1S2
(Heated oxygen)
-12.5%
Lean
Less than 0.4 V

NOTICE:
The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.


Case
Air Fuel Ratio Sensor (Sensor 1)
Output Voltage
Heated Oxygen Sensor (Sensor 2)
Output Voltage
Main Suspected Trouble Area
1
A162605E12
A162598E12
-
2
A162596E06
A162598E12
  1. Air fuel ratio sensor
  2. Air fuel ratio sensor heater
  3. Air fuel ratio sensor circuit
3
A162605E12
A162596E07
  1. Heated oxygen sensor
  2. Heated oxygen sensor heater
  3. Heated oxygen sensor circuit
  4. Exhaust gas leaks
4
A162596E06
A162596E06
  1. Fuel pressure
  2. Exhaust gas leaks
    (Air fuel ratio extremely lean or rich)
  1. Performing Control the Injection Volume for A/F Sensor enables technicians to check and graph the output voltages of both the air fuel ratio and heated oxygen sensors.
  2. To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / AFS Voltage B1S1 and O2S B2S1.

HINT:
  1. Refer to "Data List / Active Test"[ AFS Voltage B1S1] (Click here).
  2. 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 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.
  3. Sensor 1 refers to the sensor closest to the engine assembly.
  4. Sensor 2 refers to the sensor farthest away from the engine assembly.

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

  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
    D24-1 (HA1A) - D28-18 (HA1A)
    		Always
    		Below 1 Ω
    D24-3 (A1A+) - D28-103 (A1A+)
    		Always
    		Below 1 Ω
    D24-4 (A1A-) - D28-126 (A1A-)
    		Always
    		Below 1 Ω


    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    D24-1 (HA1A) or D28-18 (HA1A) - Body ground
    		Always
    		10 kΩ or higher
    D24-3 (A1A+) or D28-103 (A1A+) - Body ground
    		Always
    		10 kΩ or higher
    D24-4 (A1A-) or D28-126 (A1A-) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the air fuel ratio sensor connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
OK


2.REPLACE AIR FUEL RATIO SENSOR NO.2

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


NEXT


3.PERFORM CONFIRMATION DRIVING PATTERN

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Clear the DTCs.

  1. Put the engine in inspection mode (Click here).

  1. Start the engine and wait for 2 minutes.


NEXT


4.CHECK WHETHER DTC OUTPUT RECURS

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

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

  1. Read the Pending DTCs.

    Result:
    Result
    		Proceed to
    DTC is not output
    		A
    DTC P2237, P2238, P2239, P2252 or P2253 is output
    		B



B
REPLACE ECM (Click here)
A

END