P2195

4GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2195-P2198: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)


DESCRIPTION

The air fuel ratio sensor generates a voltage* that corresponds to the actual air fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air fuel ratio. The ECM determines the deviation from the stoichiometric air fuel ratio level, and regulates the fuel injection time. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air fuel ratio accurately.

The air fuel ratio sensor is the planar type and is integrated with the heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are the narrow type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, therefore the sensor activation is accelerated.

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a three-way catalytic converter is used. For the most efficient use of the three-way catalytic converter, the air fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: Value changes inside the ECM. Since the air fuel ratio sensor is a current output element, the current is converted into a voltage inside the ECM. Any measurements taken at the air fuel ratio sensor or ECM connectors will show a constant voltage.









HINT
- DTCs P2195 and P2196 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.
- DTCs P2197 and P2198 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.
- When any of these DTCs are set, check the air fuel ratio sensor output voltage by entering the following menus: Powertrain / Engine / Data List / All Data / AFS Voltage B1S1 or AFS Voltage B2S1.
- Short-term fuel trim values can also be read using the Techstream.
- The ECM regulates the voltages at the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the Techstream.
- If an air fuel ratio sensor malfunction is detected, the ECM sets a DTC.

MONITOR DESCRIPTION

Sensor Voltage Detection Monitor:

Under air fuel ratio feedback control, If the air fuel ratio sensor output voltage is less than 2.8 V (very rich condition) for 5 seconds despite the heated oxygen sensor output voltage being less than 0.59 V, the ECM stores DTC P2196 or P2198. Alternatively, if the air fuel ratio sensor output voltage is higher than 3.8 V (very lean condition) for 5 seconds despite the heated oxygen sensor output voltage being 0.21 V or higher, DTC P2195 or P2197 is stored.

Sensor Current Detection Monitor:

A rich air fuel mixture causes a low air fuel ratio sensor current, and a lean air fuel mixture causes a high air fuel ratio sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the air fuel ratio sensor current during fuel-cut and detects any abnormal current values.

If the air fuel ratio sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the air fuel ratio sensor and stores DTC P2195 or P2197 (stuck on high side). If the air fuel ratio sensor output is less than 0.78 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 or P2198 (stuck on low side).





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





Sensor Voltage Detection Monitor





Sensor Current Detection Monitor





TYPICAL MALFUNCTION THRESHOLDS

P2195 and P2197: Sensor Voltage Detection Monitor (Lean Side Malfunction)





P2196 and P2198: Sensor Voltage Detection Monitor (Rich Side Malfunction)





P2195 and P2197: Sensor Current Detection Monitor (High Side Malfunction)





P2196 and P2198: Sensor Current Detection Monitor (Low Side Malfunction)





MONITOR RESULT

Refer to Checking Monitor Status Mode 6 Data.

CONFIRMATION DRIVING PATTERN









1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG).

3. Turn the Techstream on.

4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

5. Turn the engine switch off and wait for at least 30 seconds.

6. Turn the engine switch on (IG) and turn the Techstream on.

7. Start the engine, and warm it up until the engine coolant temperature reaches 75°C (167°F) or more [A].

8. On Techstream, enter the following menus to check the fuel-cut status: Powertrain / Engine / Data List / Idle Fuel Cut.

9. Drive the vehicle at between 60 and 120 km/h (37 and 75 mph) for at least 10 minutes [B].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

10. With the shift lever in S [C], accelerate the vehicle to 64 km/h (40 mph) or more by depressing the accelerator pedal for at least 10 seconds [D].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

11. Soon after performing step [D] above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal in order to execute fuel-cut control [E].

HINT
Fuel-cut is performed when the following conditions are met:

- Accelerator pedal is fully released.
- Engine speed is 2500 rpm or more (fuel injection returns at 1400 rpm).

12. Allow the vehicle to decelerate until the vehicle speed decreases to less than 10 km/h (6 mph).

13. Repeat steps [C] through [E] above at least 3 times in one driving cycle.

14. Enter the following menus: Powertrain / Engine / Trouble Codes [F].

15. Read Pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is output, perform the following procedure.

16. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

17. Input the DTC: P2195, P2196, P2197 or P2198.

18. 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, perform steps [B] through [F] again.

19. 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





INSPECTION PROCEDURE

HINT
- 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.
- A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
- A high air fuel ratio sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.
- 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.
- 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2195, P2196, P2197 OR P2198)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch to on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result:





HINT
If any DTCs relating to the air fuel ratio sensor (DTCs for the air fuel ratio sensor heater or air fuel ratio sensor admittance) are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART SFI System
A -- Continue to next step.

2. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST

(a) Has the vehicle run out of fuel in the past?

NO -- READ VALUE USING TECHSTREAM (AIR FUEL RATIO SENSOR CURRENT)
YES -- Continue to next step.

3. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

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

(f) Turn the engine switch on (IG) and turn the Techstream on.

(g) Start the engine and warm it up.

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

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

(j) Input the DTC: P2195, P2196, P2197 or P2198.

(k) Check the DTC judgment result.

Result:





B -- READ VALUE USING TECHSTREAM (AIR FUEL RATIO SENSOR CURRENT)

A -- DTC CAUSED BY RUNNING OUT OF FUEL

4. READ VALUE USING TECHSTREAM (AIR FUEL RATIO SENSOR CURRENT)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

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

(f) Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Current.

(g) Check that the status of O2 Sensor is Complete. If the status is still Incomplete, drive the vehicle according to the driving pattern again.

(h) Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details / RANGE B1S1 or RANGE B2S1.

(i) Check the test value of the air fuel ratio sensor output current during fuel cut.

Result:





B -- REPLACE AIR FUEL RATIO SENSOR
A -- Continue to next step.

5. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

(f) Perform the Control the Injection Volume operation with the engine idling.

(g) Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.

HINT
- Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.
- The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
- If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.





Result





Lean: During the Control the Injection Volume Active Test, the air fuel ratio sensor output voltage (AFS Voltage) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S) is consistently below 0.4 V.

Rich: During the Control the Injection Volume Active Test, the AFS Voltage is consistently below 3.1 V, and the O2S is consistently higher than 0.55 V.

Lean/Rich: During the Control the Injection Volume Active Test, the output voltage of the heated oxygen sensor alternates correctly.

HINT
Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2] Data List / Active List.

B -- REPLACE AIR FUEL RATIO SENSOR
A -- Continue to next step.

6. CHECK AIR INDUCTION SYSTEM

(a) Check the air induction system for vacuum leaks Intake System.

OK:

No leaks in air induction system.

NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.

7. CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks.

NG -- REPAIR OR REPLACE EXHAUST SYSTEM
OK -- Continue to next step.

8. CHECK FUEL PRESSURE (LOW PRESSURE SIDE)

(a) Check the fuel pressure for low pressure Fuel System.

NG -- REPAIR OR REPLACE FUEL SYSTEM (LOW PRESSURE SIDE)
OK -- Continue to next step.

9. INSPECT FUEL INJECTOR ASSEMBLY

(a) Check the fuel injector assembly (whether fuel volume is high or low, and whether injection pattern is poor) Testing and Inspection.

(b) Inspect the cold start injector Testing and Inspection.

NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal
OK -- Continue to next step.

10. CHECK FUEL PRESSURE (HIGH PRESSURE SIDE)

(a) Check the fuel pressure for high pressure Fuel System.

NG -- REPAIR OR REPLACE FUEL SYSTEM (HIGH PRESSURE SIDE)
OK -- Continue to next step.

11. REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor Removal.

NEXT -- Continue to next step.

12. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

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

(f) Turn the engine switch on (IG) and turn the Techstream on.

(g) Start the engine and warm it up.

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

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

(j) Input the DTC: P2195, P2196, P2197 or P2198.

(k) Check the DTC judgment result.

Result:





B -- END
A -- Continue to next step.

13. REPLACE ECM

(a) Replace the ECM Removal.

NEXT -- Continue to next step.

14. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

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

(f) Turn the engine switch on (IG) and turn the Techstream on.

(g) Start the engine and warm it up.

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

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

(j) Input the DTC: P2195, P2196, P2197 or P2198.

(k) Check the DTC judgment result.

Result





NEXT -- END

15. REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor Removal.

NEXT -- Continue to next step.

16. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Turn the engine switch off.

(f) Turn the engine switch on (IG) and turn the Techstream on.

(g) Start the engine and warm it up.

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

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

(j) Input the DTC: P2195, P2196, P2197 or P2198.

(k) Check the DTC judgment result.

Result:





B -- REPLACE ECM Removal

A -- END