P2252
1AR-FE ENGINE CONTROL: SFI SYSTEM: P2237-P2239, P2252, P2253: Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)
DESCRIPTION
HINT
* Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.
* Sensor 1 refers to the sensor mounted in front of the three-way catalytic converter and located near the engine assembly.
The air fuel ratio 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 that the oxygen concentration in the exhaust gas is high, the voltage is high. If the air fuel ratio is rich, which means that the oxygen concentration in the exhaust gas is low, the voltage is low.
MONITOR DESCRIPTION
These DTCs are output when there is an open or short in the air fuel ratio sensor circuit, or if the air fuel ratio sensor output drops. To detect these problems, the voltage of the air fuel ratio 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 air fuel ratio 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 determines that there is a malfunction in the air fuel ratio sensor. If the same malfunction is detected in next driving cycle, the MIL is illuminated and a DTC is stored.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All
P2237 (Air Fuel Ratio Sensor Open Circuit Between A1A+ and A1A-)
P2238 (Air Fuel Ratio Sensor Low Impedance)
P2238 (Air Fuel Ratio Sensor Short Circuit Between A1A+ and A1A-, GND)
Other
TYPICAL MALFUNCTION THRESHOLDS
P2237 (Air Fuel Ratio Sensor Open Circuit Between A1A+ and A1A-)
P2238 (Air Fuel Ratio Sensor Low Impedance)
P2238 (Air Fuel Ratio Sensor Short Circuit Between A1A+ and GND)
P2239 (Air Fuel Ratio Sensor Short Circuit Between A1A+ and +B)
P2252 (Air Fuel Ratio Sensor Short Circuit Between A1A- and GND)
P2253 (Air Fuel Ratio Sensor Short Circuit Between A1A- and +B)
P2238 (Air Fuel Ratio Sensor Short Circuit Between A1A+ and A1A-)
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 procedure) Reading and Clearing Diagnostic Trouble Codes.
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 5 minutes.
7. Enter the following menus: Powertrain / Engine / Trouble Codes.
8. Read the Pending DTCs.
HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.
9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
10. Input the DTC: P2237, P2238, P2239, P2252 or P2253.
11. Check the DTC judgment result.
HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment result shows INCOMPLETE or N/A, idle the engine for 5 minutes and check the DTC judgment result again.
12. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
Refer to DTC P2195 P2195.
INSPECTION PROCEDURE
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT
* Refer to "Data List / Active Test" [AFS Voltage B1S1 and AFS Voltage B2S1] Data List / Active List.
* Read freeze frame data using the Techstream. 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.
* Bank 1 refers to the bank that includes the No. 1 cylinder*.
*: The No. 1 cylinder is the cylinder which is farthest from the transaxle.
* Bank 2 refers to the bank that does not include the No. 1 cylinder.
* Sensor 1 refers to the sensor closest to the engine assembly
* Sensor 2 refers to the sensor farthest away from the engine assembly.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
(a) Disconnect the air fuel ratio sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(d) Reconnect the air fuel ratio sensor connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
3. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Start the engine.
(f) Allow the engine to idle for 5 minutes or more.
(g) Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
(h) Read the pending DTCs.
Result:
B -- REPLACE ECM Removal
A -- END