SFI SYSTEM, Diagnostic DTC:P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255, P2256
| 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) |
| P2240 | Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 2 Sensor 1) |
| P2241 | Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 2 Sensor 1) |
| P2242 | Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 2 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) |
| P2255 | Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 2 Sensor 1) |
| P2256 | Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 2 Sensor 1) |
CAUTION / NOTICE / HINT
Tech Tips
-
Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
-
Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.
DESCRIPTION
The A/F sensor, which is located between the exhaust manifold and catalyst, consists of alloyed metal elements and a heater.
Depending on the engine operating conditions, the heater heats the sensor elements to activate them. Battery voltage is applied to the heater, and the sensor ground is controlled by the ECM using a duty ratio.
The sensor elements convert the oxygen concentration in the exhaust gas into voltage values to output. Based on the voltage, the ECM determines the air-fuel ratio and regulates the fuel injection volume depending on the air-fuel ratio and engine operating conditions. The voltage changes between 0.6 V and 4.5 V while the engine is running. If the air-fuel ratio is lean, which means the oxygen concentration in the exhaust gas is high, the voltage is high. If the air-fuel ratio is rich, which means the oxygen concentration in the exhaust gas is low, the voltage is low.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2237 P2240 |
Open in the circuit between terminals A1A+ and A1A-/A2A+ and A2A- of the AF sensor while engine is running (2 trip detection logic) |
|
| P2238 P2241 |
|
|
| P2239 P2242 |
A1A+/A2A+ voltage more than 4.5 V (2 trip detection logic) |
|
| P2252 P2255 |
A1A-/A2A- voltage 0.5 V or less (2 trip detection logic) |
|
| P2253 P2256 |
A1A-/A2A- voltage more than 4.5 V (2 trip detection logic) |
|
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 engine switch to the on (IG) position, 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 out 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 will be illuminated and a DTC will be stored.
WIRING DIAGRAM
Refer to DTC P2195 Click here.
INSPECTION PROCEDURE
Tech Tips
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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
-
CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
-
Disconnect the E47 and E48 A/F sensor connectors.
-
Turn the engine switch on (IG).
-
Measure the voltage according to the value(s) in the table below.
Standard voltage Tester Connection Switch Condition Specified Condition E47-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V E48-2 (+B) - Body ground Engine switch on (IG) 11 to 14 V -
Turn the engine switch off.
-
Disconnect the E3 and E4 ECM connectors.
-
Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open) Tester Connection Condition Specified Condition E47-1 (HA1A) - E3-5 (HA1A) Always Below 1 Ω E47-3 (A1A+) - E4-23 (A1A+) Always Below 1 Ω E47-4 (A1A-) - E4-22 (A1A-) Always Below 1 Ω E48-1 (HA2A) - E3-6 (HA2A) Always Below 1 Ω E48-3 (A2A+) - E4-21 (A2A+) Always Below 1 Ω E48-4 (A2A-) - E4-20 (A2A-) Always Below 1 Ω Standard resistance (Check for short) Tester Connection Condition Specified Condition E47-1 (HA1A) or E3-5 (HA1A) - Body ground Always 10 kΩ or higher E47-3 (A1A+) or E4-23 (A1A+) - Body ground Always 10 kΩ or higher E47-4 (A1A-) or E4-22 (A1A-) - Body ground Always 10 kΩ or higher E48-1 (HA2A) or E3-6 (HA2A) - Body ground Always 10 kΩ or higher E48-3 (A2A+) or E4-21 (A2A+) - Body ground Always 10 kΩ or higher E48-4 (A2A-) or E4-20 (A2A-) - Body ground Always 10 kΩ or higher 
NG 
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK 
-
-
REPLACE AIR FUEL RATIO SENSOR
-
Replace the air-fuel ratio sensor.
NEXT
-
-
CHECK WHETHER DTC OUTPUT RECURS
-
Connect the intelligent tester to the DLC3.
-
Turn the engine switch on (IG) and turn the tester ON.
-
Clear the DTCs Click here.
-
Start the engine.
-
Allow the engine to idle for 5 minutes or more.
-
Enter the following menus: Powertrain / Engine / DTC / Pending.
-
Read pending DTCs.
Result Display (DTC Output) Proceed to No output A P2237, P2240, P2238, P2241, P2239, P2242, P2252, P2255, P2253 or P2256 B
B
REPLACE ECM Click here
A 
END
-