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

Refer to DTC P2195 (Click here).

DTC No.
DTC Detection Condition
Trouble Area
P2237
P2240
Open in the circuit between terminals A1A+/A2A+ and A1A-/A2A- of the A/F sensor while engine is running
(2 trip detection logic)
  1. Open in Air Fuel Ratio (A/F) sensor (for Bank 1, 2 Sensor 1) circuit
  2. Air Fuel Ratio (A/F) sensor (for Bank 1, 2 Sensor 1)
  3. ECM
P2238
P2241
  1. Case 1:
Condition (a) or (b) continues for 5.0 seconds or more
(2 trip detection logic):
(a) A1A+/A2A+ voltage 0.5 V or less
(b) (A1A+/A2A+) - (A1A-/A2A-) = 0.1 V or less
  1. Case 2:
A/F sensor admittance: Less than 0.022 1/Ω
(2 trip detection logic)
  1. Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit
  2. A/F sensor (for Bank 1, 2 Sensor 1)
  3. ECM
P2239
P2242
A1A+/A2A+ voltage more than 4.5 V for 5.0 seconds or more
(2 trip detection logic)
  1. Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit
  2. A/F sensor (for Bank 1, 2 Sensor 1)
  3. ECM
P2252
P2255
A1A-/A2A- voltage 0.5 V or less for 5.0 seconds or more
(2 trip detection logic)
  1. Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit
  2. A/F sensor (for Bank 1, 2 Sensor 1)
  3. ECM
P2253
P2256
A1A-/A2A- voltage more than 4.5 V for 5.0 seconds or more
(2 trip detection logic)
  1. Open or short in A/F sensor (for Bank 1, 2 Sensor 1) circuit
  2. A/F sensor (for Bank 1, 2 Sensor 1)
  3. ECM

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

MONITOR DESCRIPTION

These DTCs are output when there is an open or short in the A/F sensor circuit, or if A/F sensor output drops.
To detect these problems, the voltage of the A/F sensor is monitored when turning the ignition switch to ON, and the admittance (admittance is an electrical term that indicates the ease of flow of current) is checked while driving. If the voltage of the A/F sensor is between 0.6 V and 4.5 V, it is considered normal. If the voltage is outside of the specified range, or the admittance is less than the standard value, the ECM will determine that there is a malfunction in the A/F sensor. If the same malfunction is detected in the next driving cycle, the MIL is illuminated and a DTC is stored.
The Air-Fuel Ratio (A/F) sensor varies its output voltage in proportion to the air-fuel ratio. If the A/F sensor impedance (alternating current resistance) or output voltage deviates greatly from the standard range, the ECM determines that there is an open or short in the A/F sensor circuit.

MONITOR STRATEGY


Related DTCs
P2237: A/F sensor (for Bank 1) open circuit between A1A+/A2A+ and A1A-/A2A-
P2238: A/F sensor (for Bank 1) short circuit between A1A+/A2A+ and A1A-/A2A-
P2238: A/F sensor (for Bank 1) short circuit between A1A+/A2A+ and GND
P2238: A/F sensor (for Bank 1) low impedance
P2239: A/F sensor (for Bank 1) short circuit between A1A+/A2A+ and +B
P2240: A/F sensor (for Bank 2) open circuit between A1A+/A2A+ and A1A-/A2A-
P2241: A/F sensor (for Bank 2) short circuit between A1A+/A2A+ and A1A-/A2A-
P2241: A/F sensor (for Bank 2) short circuit between A1A+/A2A+ and GND
P2241: A/F sensor (for Bank 1) low impedance
P2242: A/F sensor (for Bank 2) short circuit between A1A+/A2A+ and +B
P2252: A/F sensor (for Bank 1) short circuit between A1A-/A2A- and GND
P2253: A/F sensor (for Bank 1) short circuit between A1A-/A2A- and +B
P2255: A/F sensor (for Bank 2) short circuit between A1A-/A2A- and GND
P2256: A/F sensor (for Bank 2) short circuit between A1A-/A2A- and +B
Required Sensors/Components (Main)
A/F sensor
Required Sensors/Components (Related)
Engine Coolant Temperature (ECT) sensor, Crankshaft position sensor
Frequency of Operation
Continuous
Duration
10 seconds: A/F sensor open circuit between A1A+/A2A+ and A1A-/A2A- and Low impedance
5 seconds: Other
MIL Operation
2 driving cycles
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


P2237, P2238, P2240 and P2241 
Monitor runs whenever following DTCs not present
P0016, P0018 (VVT system - Misalignment)
P0017, P0019 (Exhaust VVT system - Misalignment)
P0031, P0032, P0051, P0052, P101D, P103D (Air fuel ratio sensor heater)
P006A, P0107, P0108 (Manifold absolute pressure)
P0102, P0103 (Mass air flow meter)
P0112, P0113 (Intake air temperature sensor)
P0115, P0117, P0118 (Engine coolant temperature sensor)
P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle position sensor)
P0125 (Insufficient coolant temperature for closed loop fuel control)
P0128 (Thermostat)
P0171, P0172, P0174, P0175 (Fuel system)
P0301 - P0308 (Misfire)
P0335 (Crankshaft position sensor)
P0401 (EGR system)
P0412, P0415, P0418, P0419, P1613, P1614 (Secondary air injection system control)
P0451, P0452, P0453 (EVAP system)
P0500, P0722 (Vehicle speed sensor)
P0505 (IAC valve)
P1340 (Camshaft position sensor)
P2440 - P2447 (Secondary air injection system)

P2239, P2242, P2252, P2253, P2255 and P2256 
Monitor runs whenever following DTCs not present
None

A/F Sensor - Open Circuit Between A1A+/A2A+ and A1A-/A2A- 
Battery voltage
11 V or more
Engine
Running
Estimated sensor temperature
450 to 550°C (842 to 1022°F) for P2237 and P2240
Ignition switch
ON
Time after Ignition switch is OFF to ON
5 seconds or more

A/F Sensor - Low Impedance 
Engine coolant temperature
0°C (32°F) or higher
Estimated sensor temperature
700 to 800°C (1292 to 1472°F) for P2238 and P2241
Fuel cut
Not executed

Other 
Battery voltage
11 V or higher
Ignition switch
ON
Timing after ignition switch off to ON
5 seconds or more

TYPICAL MALFUNCTION THRESHOLDS


P2237 and P2240 (A/F Sensor Open Circuit Between A1A+ and A1A-/A2A+ and A2A-) 
A/F sensor admittance
Less than 0.002 1/Ω

P2238 and P2241 (A/F Sensor Low Impedance) 
A/F sensor admittance
Less than 0.0074 1/Ω

P2238 and P2241 (A/F Sensor Short Circuit Between A1A+ and GND/A2A+ and GND) 
A1A+/A2A+ terminal voltage
0.5 V or less

P2239 and P2242 (A/F Sensor Short Circuit Between A1A+ and +B/A2A+ and +B) 
A1A+/A2A+ terminal voltage
More than 4.5 V

P2252 and P2255 (A/F Sensor Short Circuit Between A1A- and GND/A2A- and GND) 
A1A-/A2A- terminal voltage
0.5 V or less

P2253 and P2256 (A/F Sensor Short Circuit Between A1A- and +B/A2A- and +B) 
A1A-/A2A- terminal voltage
More than 4.5 V

P2238 and P2241 (A/F Sensor Short Circuit Between A1A+ and A1A-/A2A+ and A2A-) 
Difference between A1A+ and A1A-/A2A+ and A2A- terminal voltage
0.1 V or less

CONFIRMATION DRIVING PATTERN


A199234E02

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear 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 [A].
  6. Start the engine and wait 2 minutes.
  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].
  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.

    Tester Display
    		Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. 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

Refer to DTC P2195 (Click here).

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.CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
A160209E15

  1. Disconnect the A/F sensor connector.

  1. Disconnect the ECM connector.

  1. 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


2.REPLACE AIR FUEL RATIO SENSOR

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


NEXT


3.CHECK WHETHER DTC OUTPUT RECURS

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Clear DTCs (Click here).

  1. Start the engine.

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

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

  1. 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