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
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 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 of the planar type and is integrated with 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 air fuel ratio detection. The heat generated by the heater is conducted to the solid electrolyte through the alumina, therefore the sensor activation is accelerated.
A three way catalytic converter is used in order to convert the carbon monoxide, hydrocarbons and nitrogen oxide into less harmful substances. To allow the three way catalytic converter to function effectively, it is necessary to keep the air fuel ratio of the engine near the stoichiometric air fuel ratio.
*: The value changes inside the ECM. Since the air fuel ratio sensor is a current output element, 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): (a) Air fuel ratio sensor voltage is higher than 3.8 V. (b) Heated oxygen sensor voltage is 0.21 V or higher. |
|
While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is 2.2 mA or higher for 3 seconds (2 trip detection logic). |
|
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P2196 | Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic): (a) Air fuel ratio sensor voltage is below 2.8 V. (b) Heated oxygen sensor voltage is below 0.71 V. |
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While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is below 0.7 mA for 3 seconds (2 trip detection logic). |
|
Tech Tips
When either of these DTCs is output, check the air fuel ratio sensor output voltage by entering the following menus on the GTS: Powertrain / Engine and ECT / Data List / AFS Voltage B1S1.
Short-term fuel trim values can also be read using the GTS.
The ECM regulates the voltages at the A1A+ and A1A- terminals of the ECM to a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the GTS.
If the air fuel ratio sensor is malfunctioning, the ECM stores DTC P2195 or P2196.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs Click here.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [A].
On the GTS, enter the following menus to check the fuel-cut status: Powertrain / Engine and ECT / Data List / Idle Fuel Cut.
Drive the vehicle at a speed between 60 and 100 km/h (37 and 63 mph) for at least 10 minutes [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Shift the transaxle to 2nd gear [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.
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].
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 / Trouble Codes / Pending [F].
Read the pending DTCs.
Tech Tips
If a pending DTC is output, the system is malfunctioning.
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.
GTS Display | Description |
---|---|
NORMAL |
|
ABNORMAL |
|
INCOMPLETE |
|
N/A |
|
Tech Tips
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.
CAUTION / NOTICE / HINT
Tech Tips
Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.
Read freeze frame data using the GTS. 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.
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.
PROCEDURE
CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs.
Result | Proceed to |
---|---|
P2195 or P2196 is output | A |
"P2195 or P2196" and "P0136, P0137 or P0138" are output | A |
P2195 or P2196 and other DTCs are output | B |
Tech Tips
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 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 GTS (AIR FUEL RATIO SENSOR CURRENT) Click here |
YES |
PERFORM CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs Click here.
Turn the ignition switch off and wait for 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in 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.
Result | Proceed to |
---|---|
NORMAL (DTC is not output) | A |
ABNORMAL (DTC P2195 or P2196 is output) | B |
A |
DTC CAUSED BY RUNNING OUT OF FUEL |
B |
READ VALUE USING GTS (AIR FUEL RATIO SENSOR CURRENT)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs Click here.
Enter the following menus: Powertrain / Engine and ECT / Data List / AFS Current B1S1.
Check the value of the air fuel ratio sensor output current during fuel-cut, referring to the Monitor Drive Pattern Detail for Procedure "C" though Procedure "E" in the Confirmation Driving Pattern.
Tech Tips
To measure the air fuel ratio sensor current precisely, perform the fuel-cut operation as long as possible.
If it is difficult to measure the air fuel ratio sensor current, use the snapshot function of the GTS.
Result | ||||||
---|---|---|---|---|---|---|
|
B |
REPLACE AIR FUEL RATIO SENSOR Click here |
A |
READ VALUE USING GTS (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)
Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
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 / Active Test / Control the Injection Volume for A/F Sensor / Data List / AFS Voltage B1S1 and O2S B1S2.
Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.
Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the GTS.
Tech Tips
Change the fuel injection volume within the range of -12.5% to 12.5%.
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.
GTS Display (Sensor) | Injection Volume | Status | Voltage |
---|---|---|---|
AFS Voltage B1S1 (Air fuel ratio) |
12.5% | Rich | Below 3.1 V |
AFS Voltage B1S1 (Air fuel ratio) |
-12.5% | Lean | Higher than 3.4 V |
O2S B1S2 (Heated oxygen) |
12.5% | Rich | Higher than 0.55 V |
O2S B1S2 (Heated oxygen) |
-12.5% | Lean | Below 0.4 V |
Status of AFS Voltage B1S1 | Status of O2S B1S2 | Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition | Proceed to |
---|---|---|---|
Lean | Lean | Actual air fuel ratio lean | A |
Rich | Rich | Actual air fuel ratio rich | A |
Lean | Lean/Rich | Air fuel ratio sensor malfunction | B |
Rich | Lean/Rich | Air fuel ratio sensor malfunction | B |
Lean/Rich | Lean/Rich | Normal | B |
Lean: During the Control the Injection Volume for A/F Sensor 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 for A/F Sensor 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 for A/F Sensor Active Test, the output voltage of the heated oxygen sensor alternates correctly.
B |
REPLACE AIR FUEL RATIO SENSOR Click here |
A |
CHECK INTAKE SYSTEM
Check the intake system for vacuum leaks Click here.
OK |
---|
No leaks in intake system. |
Tech Tips
Perform "Inspection After Repair" after repairing or replacing the intake system Click here.
NG |
REPAIR OR REPLACE INTAKE SYSTEM |
OK |
CHECK FOR EXHAUST GAS LEAK
Check for exhaust gas leaks.
OK |
---|
No gas leaks. |
Tech Tips
Perform "Inspection After Repair" after repairing or replacing the exhaust system Click here.
NG |
REPAIR OR REPLACE EXHAUST SYSTEM |
OK |
CHECK FUEL PRESSURE
Check the fuel pressure Click here.
NG |
CHECK FUEL LINE Click here |
OK |
INSPECT FUEL INJECTOR ASSEMBLY
Check the fuel injector assembly (whether fuel volume is high or low, and whether injector pattern is poor) Click here.
Tech Tips
Perform "Inspection After Repair" after replacing the fuel injector assembly Click here.
NG |
REPLACE FUEL INJECTOR ASSEMBLY Click here |
OK |
REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor Click here.
Tech Tips
Perform "Inspection After Repair" after replacing the air fuel ratio sensor Click here.
NEXT |
PERFORM CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs Click here.
Turn the ignition switch off and wait for 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in 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.
Result | Proceed to |
---|---|
ABNORMAL (DTC P2195 or P2196 is output) | A |
NORMAL (DTC is not output) | B |
B |
END |
A |
REPLACE ECM
Replace the ECM Click here.
NEXT |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTC Click here.
Turn the ignition switch off and wait for 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in 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.
GTS Display | Description |
---|---|
NORMAL |
|
ABNORMAL |
|
INCOMPLETE |
|
N/A |
|
NEXT |
END |
REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor Click here.
Tech Tips
Perform "Inspection After Repair" after replacing the air fuel ratio sensor Click here.
NEXT |
PERFORM CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs Click here.
Turn the ignition switch off and wait for 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in 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.
Result | Proceed to |
---|---|
NORMAL (DTC is not output) | A |
ABNORMAL (DTC P2195 or P2196 is output) | B |
A |
END |
B |
REPLACE ECM Click here |
CHECK FUEL LINE
Check the fuel lines for leaks or blockage.
Tech Tips
Perform "Inspection After Repair" after replacing the fuel pump Click here.
OK |
REPLACE FUEL PUMP Click here |
NG |
REPAIR OR REPLACE FUEL LINE |