| DTC Code | DTC Name |
|---|---|
| P2195 | Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1) |
| P2196 | Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1) |
DESCRIPTION
Tech Tips
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 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.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2195 | Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic)
|
|
| While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 3.6 mA or more for 3 seconds (2 trip detection logic) |
|
|
| P2196 | Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic)
|
|
| While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is less than 1.0 mA for 3 seconds (2 trip detection logic) |
|
Tech Tips
When any of these DTCs are set, check the air fuel ratio sensor voltage output by entering the following menus on the intelligent tester: Powertrain / Engine and ECT / Data List / All Data / AFS Voltage B1S1.
Short-term fuel trim values can also be read using the intelligent tester.
The ECM regulates the voltages at the A1A+ and A1A- terminals of the ECM to a constant level. Therefore, the air fuel ratio sensor voltage output cannot be confirmed without using the intelligent tester.
If an air fuel ratio sensor malfunction is detected, the ECM sets a DTC.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
CAUTION:
Strictly observe posted speed limits, traffic laws, and road conditions when performing these drive patterns.
Tech Tips
This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off.
Turn the power switch on (IG) and turn the tester on.
Put the engine in inspection mode Click here.
Start the engine, and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [A].
On the intelligent tester, enter the following menus to check the fuel-cut status: Powertrain / Engine and ECT / Data List / All Data / Idle Fuel Cut.
Drive the vehicle at between 75 and 120 km/h (47 and 75 mph) for at least 10 minutes [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Move the shift lever in B [C].
Accelerate the vehicle to 75 km/h (47 mph) or more by depressing the accelerator pedal for at least 10 seconds [D].
Soon after performing step [D] above, release the accelerator pedal for at least 8 seconds without depressing the brake pedal in order to execute fuel-cut control [E].
Tech Tips
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 1000 rpm).
Allow the vehicle to decelerate until the vehicle speed decreases to less than 10 km/h (6 mph).
Repeat steps [C] through [E] above at least 3 times in one driving cycle.
Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
Read the pending DTC [F].
If a pending DTC is output, the system is malfunctioning.
Tech Tips
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2195 or P2196.
Check the DTC judgment result.
| Tester Display | Description |
|---|---|
| NORMAL |
|
| ABNORMAL |
|
| INCOMPLETE |
|
| UNKNOWN |
|
Tech Tips
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows NORMAL, the system is normal.
If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [F].
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Check the judgement result.
Tech Tips
If a the judgement result shows ABNORMAL, the system has a malfunction.
If a the judgement result shows NORMAL, the system is normal.
INSPECTION PROCEDURE
Tech Tips
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 to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the intelligent tester.
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG) and turn the tester on.
Put the engine in inspection mode Click here.
Start the engine.
Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the intelligent tester.
Tech Tips
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%.
Each sensor reacts in accordance with increases in the fuel injection volume.
| Tester Display (Sensor) |
Injection Volume | Status | Voltage |
|---|---|---|---|
| AFS Voltage B1S1 (Air fuel ratio) |
+25% | Rich | Less than 3.1 V |
| AFS Voltage B1S1 (Air fuel ratio) |
-12.5% | Lean | More than 3.4 V |
| O2S B1S2 (Heated oxygen) |
+25% | Rich | More than 0.55 V |
| O2S B1S2 (Heated oxygen) |
-12.5% | Lean | Less than 0.4 V |
Note
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.
| Case | Air Fuel Ratio Sensor (Sensor 1) Output Voltage |
Heated Oxygen Sensor (Sensor 2) Output Voltage |
Main Suspected Trouble Area |
|---|---|---|---|
| 1 | |
|
- |
| 2 | |
|
|
| 3 | |
|
|
| 4 | |
|
|
Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.
To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS Voltage B1S1 and O2S B1S2.
Tech Tips
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.
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.
PROCEDURE
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
Tech Tips
If any DTCs other than P2195 and P2196 are output, troubleshoot those DTCs first.
| B |
|
GO TO DTC CHART Click here |
| A |
|
CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
Has the vehicle run out of fuel in the past?
| NO |
|
READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF AIR FUEL RATIO SENSOR) Click here |
| YES |
|
DTC CAUSED BY RUNNING OUT OF FUEL
READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF AIR FUEL RATIO SENSOR)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Put the engine in inspection mode Click here.
Allow the vehicle to drive in accordance with the drive pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Current B1S1.
Read the value of the air fuel ratio sensor output current during fuel-cut.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE AIR FUEL RATIO SENSOR NO.2 Click here |
| A |
|
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG) and turn the tester on.
Put the engine in inspection mode Click here.
Start the engine.
Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.
Enter the following menus: Powertrain / Engine and ECT / Data List / AFS Voltage B1S1 and Engine Speed, then press the Record button.
Check the air fuel ratio sensor voltage 3 times, when the engine is in each of the following conditions:
(1) While idling (check for at least 30 seconds) (Step "A").
(2) At an engine speed of approximately 2500 rpm (without any sudden changes in engine speed) (Step "B").
(3) The engine speed is raised to 2500 rpm and then the accelerator pedal is quickly released so that the throttle valve is fully closed (Step "C").
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
For more information, see the diagrams below.
Tech Tips
If the output voltage of the air fuel ratio sensor remains at approximately 3.3 V (see Malfunction Condition diagram) under any conditions, including those above, the air fuel ratio sensor may have an open circuit. (This will also happen if the air fuel ratio sensor heater has an open circuit.)
If the output voltage of the air fuel ratio sensor remains at either approximately 3.8 V or higher, or below 2.8 V (see Malfunction Condition diagram) under any conditions, including those above, the air fuel ratio sensor may have a short circuit.
The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and results in a momentary increase in the air fuel ratio sensor output voltage.
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.
When the vehicle is driven:
The output voltage of the air fuel ratio 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 air fuel ratio sensor is functioning normally.
The air fuel ratio 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 air fuel ratio sensor or ECM will show a constant voltage result.
| NG |
|
| OK |
|
PERFORM CONFIRMATION DRIVING PATTERN
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs.
Put the engine in inspection mode Click here.
Drive the vehicle referring to the Confirmation Driving Pattern.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
Read the Pending DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |
| A |
|
REPLACE AIR FUEL RATIO SENSOR NO.2
Replace the air fuel ratio sensor Click here.
| NEXT |
|
PERFORM CONFIRMATION DRIVING PATTERN
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs.
Put the engine in inspection mode Click here.
Drive the vehicle referring to the Confirmation Driving Pattern.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
Read the Pending DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
END |
| A |
|
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tech Tips
The A/C switch and all accessory switches should be off.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.
Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.
Note
Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.
| OK |
|---|
| MAP change in response to EGR step position when Throttle Idle Position is ON in Data List. |
| Standard | ||||||||
|---|---|---|---|---|---|---|---|---|
|
||||||||
Tech Tips
While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE ECM Click here |
| A |
|
INSPECT EGR VALVE ASSEMBLY
Remove the EGR valve assembly Click here.
Check if the EGR valve is stuck open.
| OK |
|---|
| EGR valve is tightly closed. |
Reinstall the EGR valve assembly Click here.
| NG |
|
REPLACE EGR VALVE ASSEMBLY Click here |
| OK |
|
REPLACE ECM
Replace the ECM Click here.
| NEXT |
|
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off and wait for 30 seconds.
Turn the power switch on (IG) and turn the tester on.
Put the engine in inspection mode Click here.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2195 or P2196.
Check the DTC judgment result.
| NEXT |
|
END
INSPECT AIR FUEL RATIO SENSOR NO.2 (HEATER RESISTANCE)
| *1 | Component without harness connected (to Air Fuel Ratio Sensor) |
Disconnect the air fuel ratio sensor connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the air fuel ratio sensor connector.
| NG |
|
REPLACE AIR FUEL RATIO SENSOR NO.2 Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
Disconnect the air fuel ratio sensor connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Open) | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Standard Resistance (Check for Short) | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| *1 | Front view of wire harness connector (to Air Fuel Ratio Sensor) |
*2 | Front view of wire harness connector (to ECM) |
Reconnect the air fuel ratio sensor connector.
Reconnect the ECM connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM) |
| OK |
|
CHECK INTAKE SYSTEM
Check the intake system for vacuum leaks Click here.
| OK |
|---|
| No leaks from the intake system. |
| NG |
|
REPAIR OR REPLACE INTAKE SYSTEM |
| OK |
|
CHECK FUEL PRESSURE
Check the fuel pressure Click here.
| NG |
|
REPAIR OR REPLACE FUEL SYSTEM |
| OK |
|
INSPECT FUEL INJECTOR ASSEMBLY
Check the fuel injector assembly injection (whether fuel volume is high or low, and whether injection pattern is poor) Click here.
| NG |
|
REPLACE FUEL INJECTOR ASSEMBLY Click here |
| OK |
|
REPLACE AIR FUEL RATIO SENSOR NO.2
Replace the air fuel ratio sensor Click here.
| NEXT |
|
PERFORM CONFIRMATION DRIVING PATTERN
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs.
Put the engine in inspection mode Click here.
Drive the vehicle referring to the Confirmation Driving Pattern.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
Read the Pending DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
END |
| A |
|
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tech Tips
The A/C switch and all accessory switches should be off.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.
Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.
Note
Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.
| OK |
|---|
| MAP change in response to EGR step position when Throttle Idle Position is ON in Data List. |
| Standard | ||||||||
|---|---|---|---|---|---|---|---|---|
|
||||||||
Tech Tips
While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE ECM Click here |
| A |
|
INSPECT EGR VALVE ASSEMBLY
Remove the EGR valve assembly Click here.
Check if the EGR valve is stuck open.
| OK |
|---|
| EGR valve is tightly closed. |
Reinstall the EGR valve assembly Click here.
| NG |
|
REPLACE EGR VALVE ASSEMBLY Click here |
| OK |
|
REPLACE ECM
Replace the ECM Click here.
| NEXT |
|
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off and wait for 30 seconds.
Turn the power switch on (IG) and turn the tester on.
Put the engine in inspection mode Click here.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2195 or P2196.
Check the DTC judgment result.
| NEXT |
|
END
REPLACE AIR FUEL RATIO SENSOR NO.2
Replace the air fuel ratio sensor Click here.
| NEXT |
|
PERFORM CONFIRMATION DRIVING PATTERN
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs.
Put the engine in inspection mode Click here.
Drive the vehicle referring to the Confirmation Driving Pattern.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
Read the Pending DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE ECM Click here |
| A |
|
CHECK FOR INTERMITTENT PROBLEMS Click here