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) |
P2197 | Oxygen (A/F) Sensor Signal Stuck Lean (Bank 2 Sensor 1) |
P2198 | Oxygen (A/F) Sensor Signal Stuck Rich (Bank 2 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 a 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 through the heater to heat the sensor in order to facilitate accurate air-fuel ratio 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, thereby accelerating the sensor activation.
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 (TWC) is used. For the most efficient use of the Three-Way Catalytic Converter (TWC), the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.
*: The 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 P2197 |
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. |
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While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is 3.6 mA or higher for 3 seconds (2 trip detection logic). |
|
|
P2196 P2198 |
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 0.59 V. |
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While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is below 1.4 mA for 3 seconds (2 trip detection logic). |
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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 is stored, check the air fuel ratio sensor output voltage by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Voltage B1S1 or AFS Voltage B2S1.
Short-term fuel trim values can also be read using the GTS.
The ECM maintains the voltages at the A1A+ and A1A-, and A2A+ and A2A- terminals of the ECM at 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, P2196, P2197 or P2198.
MONITOR DESCRIPTION
Sensor voltage detection monitorUnder air-fuel ratio feedback control, If the air fuel ratio sensor output voltage is below 2.8 V (very rich condition) for 5 seconds despite the rear heated oxygen sensor output voltage being below 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 rear heated oxygen sensor output voltage being 0.21 V or higher, DTC P2195 or P2197 is stored.
Sensor current detection monitorA 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 higher 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 below 1.4 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 or P2198 (stuck on low side).
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 engine switch on (IG).
Turn the GTS on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the GTS on.
Start the engine and warm it up until the ECT 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 (38 and 63 mph) for at least 10 minutes [B].
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Shift the transmission to 2nd gear [C].
Accelerate the vehicle to 60 km/h (38 mph) or more by depressing the accelerator pedal for at least 10 seconds [D].
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].
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 [F].
Read the pending DTCs.
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, P2196, P2197 or P2198.
Check the DTC judgment result.
GTS Display | Description |
---|---|
NORMAL |
|
ABNORMAL |
|
INCOMPLETE |
|
N/A |
|
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.
INSPECTION PROCEDURE
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 (TWC) and located near the engine assembly.
Read freeze frame data using the GTS. 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.
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
CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, P2197 OR P2198)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read DTCs.
Result | Proceed to |
---|---|
P2195, P2196, P2197 or P2198 is output | A |
"P2195, P2196, P2197 or P2198" and "P0136, P0137, P0138, P0156, P0157 or P0158" are output | A |
P2195, P2196, P2197 or P2198 and other DTCs are output | B |
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.
CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
Has the vehicle run out of fuel in the past?
PERFORM CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs (Click here).
Turn the engine switch off.
Turn the engine switch on (IG) 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, P2196, P2197 or P2198.
Check the DTC judgment result.
Result | Proceed to |
---|---|
NORMAL (DTC is not output) | A |
ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) | B |
READ VALUE USING GTS (TEST VALUE OF AIR FUEL RATIO SENSOR)
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear the DTCs (Click here).
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Current B1S1 and AFS Current B2S1.
Check the test value of the air fuel ratio sensor output current during fuel-cut.
Result | ||||||
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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.
Perform the Control the Injection Volume operation with the engine idling.
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 GTS.
Change the fuel injection volume within the range of -12.5% to +12.5%. 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 air fuel ratio sensor output voltage does not change (almost no reaction) while performing the Active Test, the air fuel ratio sensor may be malfunctioning.
GTS Display (Sensor) | Injection Volume | Status | Voltage |
---|---|---|---|
AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio) |
+12.5% | Rich | Below 3.1 V |
AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio) |
-12.5% | Lean | Higher than 3.4 V |
O2S B1S2 or O2S B2S2 (Heated oxygen) |
+12.5% | Rich | Higher than 0.55 V |
O2S B1S2 or O2S B2S2 (Heated oxygen) |
-12.5% | Lean | Below 0.4 V |
Status of AFS Voltage B1S1 or AFS Voltage B2S1 | Status of O2S B1S2 or O2S B2S2 | 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 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.
Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2] (Click here).
CHECK INTAKE SYSTEM
Check the intake system for vacuum leaks (Click here).
OK |
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No leaks in intake system. |
CHECK FOR EXHAUST GAS LEAK
Check for exhaust gas leaks.
OK |
---|
No gas leaks. |
CHECK FUEL PRESSURE
Check the fuel pressure (Click here).
INSPECT FUEL INJECTOR ASSEMBLY
Check the fuel injector assembly (whether fuel volume is high or low, and whether injector pattern is poor) (Click here).
REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor (Click here).
PERFORM CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs (Click here).
Turn the engine switch off.
Turn the engine switch on (IG) 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, P2196, P2197 or P2198.
Check the DTC judgment result.
Result | Proceed to |
---|---|
ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) | A |
NORMAL (DTC is not output) | B |
REPLACE ECM
Replace the ECM (Click here).
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTC (Click here).
Turn the engine switch off.
Turn the engine switch on (IG) 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, P2196, P2197 or P2198.
Check the DTC judgment result.
GTS Display | Description |
---|---|
NORMAL |
|
ABNORMAL |
|
INCOMPLETE |
|
N/A |
|
REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor (Click here).
PERFORM CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs (Click here).
Turn the engine switch off.
Turn the engine switch on (IG) 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, P2196, P2197 or P2198.
Check the DTC judgment result.
Result | Proceed to |
---|---|
NORMAL (DTC is not output) | A |
ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) | B |
CHECK FUEL LINE
Check the fuel lines for leaks or blockage.
GO TO DTC CHARTClick here
DTC CAUSED BY RUNNING OUT OF FUEL
REPAIR OR REPLACE INTAKE SYSTEM
REPAIR OR REPLACE EXHAUST SYSTEM
REPLACE FUEL INJECTOR ASSEMBLYClick here
END
END
END
REPLACE ECMClick here
REPLACE FUEL PUMPClick here
REPAIR OR REPLACE FUEL LINE