Dtc P2195 Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)

READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF A/F SENSOR)

READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF A/F SENSOR)

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

REPLACE AIR-FUEL RATIO SENSOR

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

INSPECT AIR-FUEL RATIO SENSOR (HEATER RESISTANCE)

INSPECT ENGINE ROOM J/B (EFI RELAY, EFI MAIN FUSE)

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

REPLACE AIR-FUEL RATIO SENSOR

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

DESCRIPTION

HINT:

1. Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
   
2. Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.
   

HINT:

1. When either of these DTCs is set, check the A/F sensor output voltage by selecting the following menu items on the intelligent tester: Powertrain / Engine and ECT / Data List / A/F Control System / AFS B1 S1.
   
2. Short-term fuel trim values can also be read using the intelligent tester.
   
3. The ECM regulates the voltages at the A1A+ and A1A- terminals of the ECM to a constant level. Therefore, the A/F sensor output voltage cannot be confirmed without using the intelligent tester.
   
4. If the A/F sensor is malfunctioning, the ECM sets the DTC P2195 or P2196.
   

MONITOR DESCRIPTION

1. Sensor voltage detection monitor
   Under the air-fuel ratio feedback control, if the A/F sensor output voltage indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the A/F sensor. The ECM illuminates the MIL and sets a DTC.
   Example:
   If the A/F sensor output voltage is less than 2.8 V (very rich condition) for 10 seconds, despite the rear HO2 sensor output voltage being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor output voltage is more than 3.8 V (very lean condition) for 10 seconds, despite the rear HO2 sensor output voltage being 0.15 V or more, DTC P2195 is set.
   

1. Sensor current detection monitor
   A rich air-fuel mixture causes a low A/F sensor current, and a lean air-fuel mixture causes a high A/F 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 A/F sensor current during fuel-cut and detects any abnormal current values.
   If the A/F 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 A/F sensor and sets DTC P2195 (high-side stuck). If the A/F sensor output is less than 1.0 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).
   

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

1. This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN" procedure of the following diagnostic troubleshooting procedure.
   
   
   
   
   
   
   
   
   
   
   
1. Connect the intelligent tester to the DLC3.
   
2. Turn the ignition switch to the ON position.
   
3. Turn the tester on.
   
4. Clear the DTCs (CAMRY_ACV40 RM000000PDK081X.html).
   
5. Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher.
   
6. On the intelligent tester, select the following menu items to check the fuel-cut status: Powertrain / Engine and ECT / Data List / All Data / Idle Fuel Cut.
   
7. Drive the vehicle at between 60 km/h (38 mph) and 120 km/h (75 mph) for at least 10 minutes.
   
8. Change the transmission to the 2nd gear.
   
9. Drive the vehicle at a proper vehicle speed to perform fuel-cut operation (refer to the following HINT).
   

   HINT:

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

   1. Accelerator pedal fully is released.
      
   2. Engine speed is 2,500 rpm or more (fuel injection resumes at 1,000 rpm).
      
10. Accelerate the vehicle to 64 km/h (40 mph) or more by depressing the accelerator pedal for at least 10 seconds.
    
11. Soon after performing step (j) above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal, in order to execute fuel-cut control.
    
12. Allow the vehicle to decelerate until the vehicle speed declines to less than 10 km/h (6 mph).
    
13. Repeat steps from (h) through (k) above at least 3 times in one driving cycle.
    

    CAUTION:

    Strictly observe posted speed limits, traffic laws, and road conditions when performing these driving patterns.

INSPECTION PROCEDURE

HINT:

Intelligent tester only:

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

1. Connect the intelligent tester to the DLC3.
   
2. Start the engine and turn the tester on.
   
3. Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
   
4. On the tester, select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
   
5. Perform the "Control the Injection Volume for A/F Sensor" operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
   
6. Monitor the output voltages of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2) displayed on the tester.
   

HINT:

1. The "Control the Injection Volume for A/F Sensor" operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
   
2. The sensors react in accordance with increases and decreases in the fuel injection volume.
   

Standard:

Tester Display (Sensor)	Injection Volume	Status	Voltage
AFS B1 S1 (A/F)	+25%	Rich	Less than 3.0
	-12.5%	Lean	More than 3.35
O2S B1 S2 (HO2)	+25%	Rich	More than 0.5
	-12.5%	Lean	Less than 0.4

NOTICE:

The A/F sensor has an output delay of a few seconds and the HO2 sensor (sensor 2) output has a maximum output delay of approximately of 20 seconds.

Case	A/F Sensor (Sensor 1) Output Voltage		HO2 Sensor (Sensor 2) Output Voltage		Main Suspected Trouble Area
1	Injection Volume +25% -12.5%		Injection Volume +25% -12.5%		-
	Output Voltage More than 3.35 V Less than 3.0 V		Output Voltage More than 0.5 V Less than 0.4 V
2	Injection Volume +25% -12.5%		Injection Volume +25% -12.5%		A/F sensor A/F sensor heater A/F sensor circuit
	Output Voltage Almost no reaction		Output Voltage More than 0.5 V Less than 0.4 V
3	Injection Volume +25% -12.5%		Injection Volume +25% -12.5%		HO2 sensor HO2 sensor heater HO2 sensor circuit
	Output Voltage More than 3.35 V Less than 3.0 V		Output Voltage Almost no reaction
4	Injection volume +25% -12.5%		Injection Volume +25% -12.5%		Injector Fuel pressure Gas leakage from exhaust system (Air-fuel ratio extremely lean or rich)
	Output Voltage Almost no reaction		Output Voltage Almost no reaction

1. Following the "Control the Injection Volume for A/F Sensor" procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
   
2. To display the graph, select the following menu items on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / Enter / View / AFS B1 S1 and O2S B1 S2.
   

HINT:

1. DTC P2A00 may be set when the air-fuel ratio is stuck rich or lean.
   
2. Read freeze frame data using the intelligent tester. 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.
   
3. A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.
   
4. A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would cause the engine to run lean.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position.
   

3. Turn the tester on.
   

4. Select the following menu items: Powertrain / Engine and ECT / DTC.
   

5. Read the DTCs.
   
   

   Result:

   
   

   Display (DTC Output)	Proceed to
   P2195 or P2196	A
   P2195 or P2196 and other DTCs	B

HINT:

If any DTCs relating to the A/F sensor (DTCs for the A/F sensor heater or A/F sensor admittance) are output, troubleshoot those DTCs first.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position and turn the tester on.
   

3. Clear the DTCs (CAMRY_ACV40 RM000000PDK081X.html).
   

4. Drive the vehicle in accordance with the drive pattern described in the CONFIRMATION DRIVING PATTERN.
   

5. Select the following menu items: Powertrain / Engine and ECT / Data List / Monitor Status.
   

6. Check that the status of "O2S (A/FS) Monitor" is "Complete".
   If the status is still "Incomplete", drive the vehicle according to the driving pattern again.
   

   HINT:

   1. "Available" indicates that the component has not been monitored yet.
      
   2. "Complete" indicates that the component is functioning normally.
      
   3. "Incomplete" indicates that the component is malfunctioning.
      

7. Select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / AFS B1 S1.
   

8. Check the test value of the A/F sensor output current during fuel-cut (Refer to the Monitor Driving Pattern 2 [Detail for (h) through (k)] in the CONFIRMATION DRIVING PATTERN).
   

Result:

Test Value	Proceed to
Within normal range (1.0 mA or more, and less than 3.6 mA)	A
Outside normal range (Less than 1.0 mA, or 3.6 mA or more)	B

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine.
   

3. Turn the tester on.
   

4. Warm up the A/F sensor at an engine speed of 2,500 rpm for 90 seconds.
   

5. On the tester, select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / Snapshot / AFS B1 S1 and Engine Speed.
   

6. Check the A/F sensor voltage 3 times, when the engine is in each of the following conditions:
   

   1. While idling (for at least 30 seconds)
      

   2. At an engine speed of approximately 2,500 rpm (without any sudden changes in engine speed)
      

   3. Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.
      
      

      Standard voltage:

      
      

      Condition	A/F Sensor Voltage Variation	Reference
      (1) and (2)	Remains at approximately 3.3 V	Between 3.1 V and 3.5 V
      (3)	Increases to 3.8 V or more	This occurs during engine deceleration (when fuel-cut performed)

HINT:

1. For more information, see the diagrams below.
   
   
   
   
   
   
2. If the output voltage of the A/F sensor remains at approximately 3.3 V (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have an open circuit. (This will also happen if the A/F sensor heater has an open circuit.)
   
3. If the output voltage of the A/F sensor remains at either approximately 3.8 V or more, or 2.8 V or less (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have a short circuit.
   
4. The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and results in a momentary increase in the A/F sensor output voltage.
   
5. The ECM must establish a closed throttle valve position learning value to perform fuel cut. If the battery terminal has been reconnected, the vehicle must be driven over 16 km/h (10 mph) to allow the ECM to learn the closed throttle valve position.
   
6. When the vehicle is driven:
   The output voltage of the A/F sensor may be below 2.8 V during fuel enrichment. For the vehicle, this translates to a sudden increase in speed with the accelerator pedal fully depressed when trying to overtake another vehicle. The A/F sensor is functioning normally.
   
7. The A/F sensor is a current output element; therefore, the current is converted into a voltage inside the ECM. Measuring the voltage at the connectors of the A/F sensor or ECM will show a constant voltage result.
   

1. Read the DTCs using the intelligent tester.
   

2. Select the following menu items: Powertrain / Engine and ECT / DTC.
   
   

   Result:

   
   

   Display (DTC Output)	Proceed to
   P2195 or P2196	A
   No output	B

1. Read the DTCs using the intelligent tester.
   

2. Select the following menu items: Powertrain / Engine and ECT / DTC.
   
   

   Result:

   
   

   Display (DTC Output)	Proceed to
   No output	A
   P2195 or P2196	B

1. Disconnect the C15 A/F sensor connector.
   

2. Measure the resistance between the terminals of the A/F sensor connector.
   

   Standard resistance:

   Tester Connection	Specified Condition
   HA1A (1) - +B (2)	1.8 to 3.4 Ω at 20°C (68°F)
   HA1A (1) - A1A- (4)	10 kΩ or higher

3. Reconnect the A/F sensor connector.
   

1. Inspect the EFI MAIN fuse.
   

   1. Remove the EFI MAIN fuse from the engine room J/B.
      

   2. Measure the EFI MAIN fuse resistance.
      

      Standard resistance:

      Below 1 Ω
      

   3. Reinstall the EFI MAIN fuse.
      

2. Inspect the EFI relay.
   

   1. Remove the engine room J/B from the engine room R/B.
      

   2. Measure the EFI relay resistance.
      

      Standard resistance:

      Tester Connection	Specified Condition
      1E-7 - 1E-12	10 kΩ or higher
      	Below 1 Ω (Apply battery voltage between terminals 1E-9 and 1E-11)

   3. Reinstall the engine room J/B.
      

1. Disconnect the C15 A/F sensor connector.
   

2. Turn the ignition switch to the ON position.
   

3. Measure the voltage between the +B terminal of the A/F sensor connector and body ground.
   

   Standard voltage:

   Tester Connection	Specified Condition
   +B (C15-2) - Body ground	9 to 14 V

4. Turn the ignition switch off.
   

5. Disconnect the C24 ECM connector.
   

6. Measure the resistance between the terminals of the wire harness side connectors.
   

   Standard resistance (Check for open):

   Tester Connection	Specified Condition
   HA1A (C15-1) - HA1A (C24-109)	Below 1 Ω
   A1A+ (C15-3) - A1A+ (C24-112)	Below 1 Ω
   A1A- (C15-4) - A1A- (C24-113)	Below 1 Ω

   Standard resistance (Check for short):

   Tester Connection	Specified Condition
   HA1A (C15-1) or HA1A (C24-109) - Body ground	10 kΩ or higher
   A1A+ (C15-3) or A1A+ (C24-112) - Body ground	10 kΩ or higher
   A1A- (C15-4) or A1A- (C24-113) - Body ground	10 kΩ or higher

7. Reconnect the ECM connector.
   

8. Reconnect the A/F sensor connector.
   

   
   
   
   

1. Read the DTCs using the intelligent tester.
   

2. Select the following menu items: Powertrain / Engine and ECT / DTC.
   
   

   Result:

   
   

   Display (DTC Output)	Proceed to
   No output	A
   P2195 or P2196	B