SFI SYSTEM(except K111, K111F), Diagnostic DTC:P2195, P2196

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

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, and 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.	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 (A) or (B) met (2 trip detection logic): (A) Conditions (a) and (b) continue for 5 seconds or more: Air fuel ratio sensor voltage higher than 3.8 V. Heated oxygen sensor voltage is 0.21 V or higher. (B) While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 2.2 mA or higher for 3 seconds.	Open or short in air fuel ratio sensor (sensor 1) circuit Air fuel ratio sensor (sensor 1) Intake system Fuel pressure Fuel injector assembly ECM	Comes on	DTC stored
P2196	Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)	Either of following conditions (A) or (B) met (2 trip detection logic): (A) Conditions (a) and (b) continue for 5 seconds or more: Air fuel ratio sensor voltage below 2.8 V. Heated oxygen sensor voltage is below 0.59 V. (B) While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is below 0.7 mA for 3 seconds.	Open or short in air fuel ratio sensor (sensor 1) circuit Air fuel ratio sensor (sensor 1) Intake system Fuel pressure Fuel injector assembly ECM	Comes on	DTC stored

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 (A) or (B) met (2 trip detection logic):

(A)

Conditions (a) and (b) continue for 5 seconds or more:

Air fuel ratio sensor voltage higher than 3.8 V.
Heated oxygen sensor voltage is 0.21 V or higher.

(B)

While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 2.2 mA or higher for 3 seconds.

Open or short in air fuel ratio sensor (sensor 1) circuit
Air fuel ratio sensor (sensor 1)
Intake system
Fuel pressure
Fuel injector assembly
ECM

Comes on

DTC stored

P2196

Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)

Either of following conditions (A) or (B) met (2 trip detection logic):

(A)

Conditions (a) and (b) continue for 5 seconds or more:

Air fuel ratio sensor voltage below 2.8 V.
Heated oxygen sensor voltage is below 0.59 V.

(B)

While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is below 0.7 mA for 3 seconds.

Open or short in air fuel ratio sensor (sensor 1) circuit
Air fuel ratio sensor (sensor 1)
Intake system
Fuel pressure
Fuel injector assembly
ECM

Comes on

DTC stored

Tech Tips

When any of these DTCs is stored, check the air fuel ratio sensor voltage output by entering the following menus on the GTS: Powertrain / Engine and ECT / Data List / All Data / 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 voltage output cannot be confirmed without using the GTS.
If an air fuel ratio sensor malfunction is detected, the ECM stores a DTC.

MONITOR DESCRIPTION

Sensor Voltage Detection Monitor
Under 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. 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 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 (stuck on high side). If the air fuel ratio sensor output is below 0.7 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 (stuck on low side).

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON 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].
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 62 mph) for at least 10 minutes [B].

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.
With the shift lever in S position (for CVT Models) or 2nd gear (for Manual Transaxle Models) [C], accelerate the vehicle to 60 km/h (37 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 resumes 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.
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	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

Refer to DTC P0031.

Click here

CAUTION / NOTICE / HINT

Note

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

Tech Tips

Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.
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.

PROCEDURE

CHECK 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.

Powertrain > Engine and ECT > Trouble Codes

Read the DTCs.

Result

Result	Proceed to
DTC P2195 or P2196 is output	A
DTC P2195 or P2196 and P0136, P0137 or P0138 are output	A
DTC 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.

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

GO TO STEP 4 Click here

YES

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P2195 or P2196.

Tester Display
All Readiness

Check the DTC judgment.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

NORMAL

(DTC is not output)

ABNORMAL

(DTC P2195 or P2196 is output)

DTC CAUSED BY RUNNING OUT OF FUEL

READ VALUE USING GTS (AFS CURRENT B1S1)

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Enter the following menus: Powertrain / Engine and ECT / Data List / AFS Current B1S1.

Powertrain > Engine and ECT > Data List

Tester Display

AFS Current B1S1

Tester Display
AFS Current B1S1

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

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

Outside normal range

(lower than 0.7 mA, or 2.2 mA or higher)

REPLACE AIR FUEL RATIO SENSOR Click here

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 / All Data / AFS Voltage B1S1 and O2S B1S2.

Powertrain > Engine and ECT > Active Test

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

Data List Display
AFS Voltage B1S1
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

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 (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

Result

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
Lean/Rich	Lean/Rich	Normal

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

Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage B1S1 is consistently below 3.1 V, and the O2S B1S2 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.

Tech Tips

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

Click here

GO TO STEP 15 Click here

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Click here

OK
No leaks in the intake system.

Tech Tips

Perform "Inspection After Repair" after repairing or replacing the intake system.

Click here

Result

Proceed to
OK
NG

REPAIR OR REPLACE INTAKE SYSTEM

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

Result

Proceed to
OK
NG

REPAIR OR REPLACE EXHAUST SYSTEM

CHECK FUEL PRESSURE

Check the fuel pressure.

Click here

Result

Proceed to
OK
NG

CHECK FUEL LINE Click here

INSPECT FUEL INJECTOR ASSEMBLY

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

Click here

Tech Tips

Perform "Inspection After Repair" after replacing the fuel injector assembly.

Click here

Result

Proceed to
OK
NG

REPLACE FUEL INJECTOR ASSEMBLY Click here

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

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P2195 or P2196.

Tester Display
All Readiness

Check the DTC judgment result.

Result

Proceed to

ABNORMAL

(DTC P2195 or P2196 is output)

NORMAL

(DTC is not output)

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 ignition switch to ON.
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P2195 or P2196.

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.

Tech Tips

Perform "Inspection After Repair" after replacing the fuel pump.

Click here

Result

Proceed to
OK
NG

REPLACE FUEL PUMP Click here

REPAIR OR REPLACE FUEL LINE

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

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P2195 or P2196.

Check the DTC judgment result.

Result

Proceed to

NORMAL

(DTC is not output)

ABNORMAL

(DTC P2195 or P2196 is output)

END

REPLACE ECM Click here