P2253

2ZR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2237-P2239, P2252, P2253: Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)


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 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.

HINT
- 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.













MONITOR DESCRIPTION

These DTCs are output when there is an open or short in the Air Fuel Ratio (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 the ON 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 next driving cycle, the MIL will be illuminated and a DTC will be stored.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





P2237 (A/F sensor open circuit between A1A+ and A1A-):





P2238 (A/F sensor low impedance):





Other:





TYPICAL MALFUNCTION THRESHOLDS

P2237 (A/F sensor open circuit between A1A+ and A1A-):





P2238 (A/F sensor low impedance):





P2238 (A/F sensor short circuit between A1A+ and GND):





P2238 (A/F sensor short circuit between A1A+ and A1A-):





P2239 (A/F sensor short circuit between A1A+ and +B):





P2252 (A/F sensor short circuit between A1A- and GND):





P2253 (A/F sensor short circuit between A1A- and +B):





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN

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.

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
- 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 and ECT / 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 UNKNOWN, idle the engine for 3 minutes and check the DTC judgment result again.

12. If the test result is INCOMPLETE or UNKNOWN and 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

HINT
Malfunctioning areas can be identified by performing the Control the Injection Volume function provided in the Active Test. The Control the Injection Volume function can help to determine whether the Air Fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume operation using the Techstream.

(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
(e) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
(f) Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume.)
(g) Monitor the output voltages of the A/F and HO2 sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the tester.

HINT
- Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.
- Each sensor reacts in accordance with increases and decreases in the fuel injection volume.





NOTICE:
The Air Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum output delay of approximately 20 seconds.





- Following the Control the Injection Volume procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.

- To display the graph, Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2; then press the graph button on the Data List view.

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
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.

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 DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON.

(g) Turn the Techstream on.

(h) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

(j) Input the DTC: P2237, P2238, P2239, P2240, P2252 or P2253.

(k) Check the DTC judgment.

Result





B -- REPLACE ECM Removal

A -- END