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    P2240    Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 2 Sensor 1)
DTC    P2241    Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)
DTC    P2242    Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 2 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)
DTC    P2255    Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 2 Sensor 1)
DTC    P2256    Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 2 Sensor 1)

for Preparation Click here

DESCRIPTION

HINT:

1. DTCs P2237, P2238, P2239, P2252 and P2253 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.
   
2. DTCs P2240, P2241, P2242, P2255 and P2256 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.
   
3. Bank 1 refers to the bank that includes cylinder No. 1.
   
4. Bank 2 refers to the bank that includes cylinder No. 2.
   

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.
   
2. Turn the ignition switch to ON and turn the Techstream on.
   
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
   
4. Turn the ignition switch off and wait for at least 30 seconds.
   
5. Turn the ignition switch to ON and turn the Techstream on.
   
6. Start the engine and wait 2 minutes.
   
7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
   
8. Read the pending DTCs.
   

   HINT:

   1. If a pending DTC is output, the system is malfunctioning.
      
   2. If a pending DTC is not output, perform the following procedure.
      
9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
   
10. Input the DTC: P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255 or P2256.
    
11. Check the DTC judgment result.
    
    

    Techstream 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

    HINT:

    1. If the judgment result shows ABNORMAL, the system has a malfunction.
       
    2. If the judgment result shows INCOMPLETE or N/A, idle the engine for 3 minutes and check the DTC judgment result again [C].
       
12. If no pending DTC is output, perform a universal trip and check for permanent DTCs (Click here).
    

    HINT:

    1. If a permanent DTC is output, the system is malfunctioning.
       
    2. If no permanent DTC is output, the system is normal.
       

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

1. Read freeze frame data using the Techstream. 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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
   
2. Bank 1 refers to the bank that includes the No. 1 cylinder*.
   *: The No. 1 cylinder is the cylinder which is farthest from the transmission.
   
3. Bank 2 refers to the bank that does not include the No. 1 cylinder.
   
4. Sensor 1 refers to the sensor closest to the engine assembly.
   
5. Sensor 2 refers to the sensor farthest away from the engine assembly.
   

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
   D33-1 (HA1A) - D74-22 (HA1A)	Always	Below 1 Ω
   D33-3 (A1A+) - D74-126 (A1A+)	Always	Below 1 Ω
   D33-4 (A1A-) - D74-125 (A1A-)	Always	Below 1 Ω
   D34-1 (HA2A) - D74-20 (HA2A)	Always	Below 1 Ω
   D34-3 (A2A+) - D74-103 (A2A+)	Always	Below 1 Ω
   D34-4 (A2A-) - D74-102 (A2A-)	Always	Below 1 Ω
   D33-1 (HA1A) or D74-22 (HA1A) - Body ground	Always	10 kΩ or higher
   D33-3 (A1A+) or D74-126 (A1A+) - Body ground	Always	10 kΩ or higher
   D33-4 (A1A-) or D74-125 (A1A-) - Body ground	Always	10 kΩ or higher
   D34-1 (HA2A) or D74-20 (HA2A) - Body ground	Always	10 kΩ or higher
   D34-3 (A2A+) or D74-103 (A2A+) - Body ground	Always	10 kΩ or higher
   D34-4 (A2A-) or D74-102 (A2A-) - Body ground	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

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

   HINT:

   Perform "Inspection After Repair" after replacing the air fuel ratio sensor (Click here).

NEXT

1. Drive the vehicle according to Confirmation Driving Pattern.
   

NEXT

1. Connect the Techstream to the DLC3.
   

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

3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
   

4. Read the pending DTCs.
   
   

   Result 

   Result	Proceed to
   No DTC is output	A
   P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255 or P2256 is output	B

B	REPLACE ECM (Click here)

A
END