SFI SYSTEM, Diagnostic DTC:P2195, P2196, P2197, P2198

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

Tech Tips

Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.

The air fuel ratio sensor generates 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 duration. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air fuel ratio accurately.

The air fuel ratio sensor is a planar type and 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 a narrow type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, therefore 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.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P2195	Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)	Either of following conditions 1 or 2 met: 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).	Open or short in air fuel ratio sensor (bank 1 sensor 1) circuit Air fuel ratio sensor (bank 1 sensor 1) Intake system Exhaust gas leak Fuel pressure (for low pressure side) Fuel pressure (for high pressure side) Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P2196	Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)	Either of following conditions 1 or 2 met: Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic): (a) Air fuel ratio sensor voltage is less than 2.8 V. (b) Heated oxygen sensor voltage is less than 0.59 V. While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is less than 0.47 mA for 3 seconds (2 trip detection logic).	Open or short in air fuel ratio sensor (bank 1 sensor 1) circuit Air fuel ratio sensor (bank 1 sensor 1) Intake system Exhaust gas leak Fuel pressure (for low pressure side) Fuel pressure (for high pressure side) Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P2197	Oxygen (A/F) Sensor Signal Stuck Lean (Bank 2 Sensor 1)	Either of following conditions 1 or 2 met: 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).	Open or short in air fuel ratio sensor (bank 2 sensor 1) circuit Air fuel ratio sensor (bank 2 sensor 1) Intake system Exhaust gas leak Fuel pressure (for low pressure side) Fuel pressure (for high pressure side) Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)
P2198	Oxygen (A/F) Sensor Signal Stuck Rich (Bank 2 Sensor 1)	Either of following conditions 1 or 2 met: Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic): (a) Air fuel ratio sensor voltage is less than 2.8 V. (b) Heated oxygen sensor voltage is less than 0.59 V. While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is less than 0.47 mA for 3 seconds (2 trip detection logic).	Open or short in air fuel ratio sensor (bank 2 sensor 1) circuit Air fuel ratio sensor (bank 2 sensor 1) Intake system Exhaust gas leak Fuel pressure (for low pressure side) Fuel pressure (for high pressure side) Fuel injector assembly (for port injection) Fuel injector assembly (for direct injection) ECM	Comes on (Euro-OBD) / - (Except Euro-OBD)	DTC stored (Euro-OBD) / - (Except Euro-OBD)

Tech Tips

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 stored, check the air fuel ratio sensor voltage output by entering the following menus on the GTS: Powertrain / Engine / 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 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 GTS.
If an air fuel ratio sensor malfunction is detected, the ECM will store 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 2.2 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 less than 0.47 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 or P2198 (stuck on low side).

MONITOR STRATEGY

Required Sensors/Components (Main)	Air fuel ratio sensor
Required Sensors/Components (Related)	Heated oxygen sensor
Frequency of Operation	Continuous: Sensor voltage detection monitor Once per driving cycle: Sensor current detection monitor
Duration	3 seconds: Sensor current detection monitor 5 seconds: Sensor voltage detection monitor

TYPICAL ENABLING CONDITIONS

Sensor Voltage Detection Monitor
Time after engine start	30 seconds or more
Fuel system status	Closed-loop

Sensor Current Detection Monitor
Battery voltage	11 V or higher
Engine coolant temperature	75°C (167°F) or higher
Atmospheric pressure	76 kPa(abs) [570 mmHg(abs)] or higher
Air fuel ratio sensor status	Activated
Continuous time of fuel-cut	3 seconds or more, and less than 10 seconds

TYPICAL MALFUNCTION THRESHOLDS

P2195 and P2197: Sensor Voltage Detection Monitor (Lean Side Malfunction)
Heated oxygen sensor voltage	0.21 V or higher
Air fuel ratio sensor voltage	Higher than 3.8 V

P2196 and P2198: Sensor Voltage Detection Monitor (Rich Side Malfunction)
Heated oxygen sensor voltage	Less than 0.59 V
Air fuel ratio sensor voltage	Less than 2.8 V

P2195 and P2197: Sensor Current Detection Monitor (High Side Malfunction)
Air fuel ratio sensor current	2.2 mA or higher

P2196 and P2198: Sensor Current Detection Monitor (Low Side Malfunction)
Air fuel ratio sensor current	Less than 0.47 mA

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
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 engine coolant temperature reaches 75°C (167°F) or higher [A].
Drive the vehicle at a speed 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.
Using the GTS, enter the following menus to check the fuel-cut status: Powertrain / Engine / Data List / All Data / Idle Fuel Cut.
With the shift lever in M [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
- While "Idle Fuel Cut" on the Data List is ON, fuel-cut control is being executed.
- Fuel-cut is performed when both of the following conditions are met:
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 / Trouble Codes [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 / Utility / All Readiness.
Input the DTC: P2195, P2196, P2197 or P2198.

Check the DTC judgment result.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

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.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips

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.
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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC 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 / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTC P2195, P2196, P2197 or P2198 is output	A
DTC P2195, P2196, P2197 or P2198 and P0136, P0137, P0138, P0156, P0157 or P0158 are output	A
DTC P2195, P2196, P2197 or P2198 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.

GO TO DTC CHART Click here

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST

Has the vehicle run out of fuel in the past?

Result

Proceed to
YES
NO

READ VALUE USING GTS (AFS CURRENT B1S1) Click here

YES

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

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Powertrain > Engine > Clear DTCs
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.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.

Powertrain > Engine > Utility

Tester Display

All Readiness
Input the DTC: P2195, P2196, P2197 or P2198.

Tester Display
All Readiness

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output)	B

DTC CAUSED BY RUNNING OUT OF FUEL

READ VALUE USING GTS (AFS CURRENT B1S1)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Powertrain > Engine > Clear DTCs

Enter the following menus: Powertrain / Engine / Data List / All Data / AFS Current B1S1 and AFS Current B2S1.

Powertrain > Engine > Data List

Tester Display
AFS Current B1S1
AFS Current B2S1

Check the test value of the air fuel ratio sensor output current during fuel-cut, referring to the Driving Pattern Detail for [C] through [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

Proceed to

Within normal range

(0.47 mA or higher, and lower than 2.2 mA)

Outside normal range

(lower than 0.47 mA, or 2.2 mA or higher)

REPLACE AIR FUEL RATIO SENSOR Click here

PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F 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 / Active Test / Control the Injection Volume for A/F Sensor / All Data / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

Powertrain > Engine > Active Test

Active Test Display
Control the Injection Volume for A/F Sensor

Data List Display
AFS Voltage B1S1
AFS Voltage B2S1
O2S B1S2
O2S B2S2

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 or AFS Voltage B2S1 and O2S B2S2) displayed on the GTS.

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 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 AFS Voltage B2S1 (Air fuel ratio)	12.5%	Rich	Below 3.1 V
AFS Voltage B1S1 AFS Voltage B2S1 (Air fuel ratio)	-12.5%	Lean	Higher than 3.4 V
O2S B1S2 O2S B2S2 (Heated oxygen)	12.5%	Rich	Higher than 0.55 V
O2S B1S2 O2S B2S2 (Heated oxygen)	-12.5%	Lean	Below 0.4 V

Result

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
Lean/Rich	Lean/Rich	Normal

Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor output voltages (AFS Voltage B1S1 and AFS Voltage B2S1) are consistently higher than 3.4 V, and the heated oxygen sensor output voltages (O2S B1S2 and O2S B2S2) are consistently below 0.4 V.
Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage B1S1 and AFS Voltage B2S1 are consistently below 3.1 V, and the O2S B1S2 and O2S B2S2 are 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.

Tech Tips

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

Click here

GO TO STEP 17 Click here

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Click here

OK
No leaks in the intake system.

Result

Proceed to
OK
NG

REPAIR OR REPLACE INTAKE SYSTEM

CHECK FOR EXHAUST GAS LEAK

Check for exhaust gas leaks.

OK
No gas leaks.

Result

Proceed to
OK
NG

REPAIR OR REPLACE EXHAUST SYSTEM

CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)

Check the fuel pressure (for low pressure side).

Click here

Result

Proceed to
OK
NG

CHECK FUEL LINE Click here

INSPECT FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION)

Inspect the fuel injector assembly (for port injection) (whether fuel volume is high or low, and whether injection pattern is poor).

Click here

Result

Proceed to
OK
NG

REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION) Click here

CHECK FUEL PRESSURE (FOR HIGH PRESSURE SIDE)

Check the fuel pressure (for high pressure side).

Click here

Result

Proceed to
OK
NG

REPAIR OR REPLACE FUEL SYSTEM (FOR HIGH PRESSURE SIDE)

INSPECT FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION)

Inspect the fuel injector assembly (for direct injection).

Click here

Result

Proceed to
OK
NG

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Click here

REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

Click here

Result

Proceed to
NEXT

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

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Powertrain > Engine > Clear DTCs
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.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.

Powertrain > Engine > Utility

Tester Display

All Readiness
Input the DTC: P2195, P2196, P2197 or P2198.

Check the DTC judgment result.

Result

Result	Proceed to
ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output)	A
NORMAL (DTCs are not output)	B

END

REPLACE ECM

Replace the ECM.

Click here

Result

Proceed to
NEXT

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 DTCs.

Powertrain > Engine > Clear DTCs
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.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.

Powertrain > Engine > Utility

Tester Display

All Readiness
Input the DTC: P2195, P2196, P2197 or P2198.

Check the DTC judgment result.

Result
GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

Result

Proceed to
NEXT

END

CHECK FUEL LINE

Check the fuel lines for leaks or blockage.

Result

Proceed to
OK
NG

REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

REPAIR OR REPLACE FUEL LINE

REPLACE AIR FUEL RATIO SENSOR

Replace the air fuel ratio sensor.

Click here

Result

Proceed to
NEXT

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

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.

Powertrain > Engine > Clear DTCs
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.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.

Powertrain > Engine > Utility

Tester Display

All Readiness
Input the DTC: P2195, P2196, P2197 or P2198.

Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTCs are not output)	A
ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output)	B

END

REPLACE ECM Click here