Toyota Venza: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1) (P2195,P2196)

Toyota Venza Service Manual / 1ar-fe Engine Control / Sfi System / Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1) (P2195,P2196)

DESCRIPTION

HINT:

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) (a) Air fuel ratio sensor voltage higher than 3.8 V (b) Heated oxygen sensor voltage is 0.21 V or higher	Open or short in air fuel ratio sensor (bank 1 sensor 1) circuit Air fuel ratio sensor (bank 1 sensor 1) Intake system Gas leaks from exhaust system Fuel pressure Fuel injector assembly ECM
P2195	While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 2.2 mA or more for 3 seconds (2 trip detection logic)	Air fuel ratio sensor (bank 1 sensor 1) ECM
P2196	Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic) (a) Air fuel ratio sensor voltage below 2.8 V (b) Heated oxygen sensor voltage is below 0.69 V	Open or short in air fuel ratio sensor (bank 1 sensor 1) circuit Air fuel ratio sensor (bank 1 sensor 1) Intake system Gas leaks from exhaust system Fuel pressure Fuel injector assembly ECM
P2196	While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is less than 0.7 mA for 3 seconds (2 trip detection logic)	Air fuel ratio sensor (bank 1 sensor 1) ECM

HINT:

When any of these DTCs are set, check the air fuel ratio sensor voltage output by entering the following menus on the Techstream: Powertrain / Engine / Data List / AFS Voltage B1S1.
Short-term fuel trim values can also be read using the Techstream.
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 Techstream.
If an air fuel ratio sensor malfunction is detected, the ECM sets a DTC.

MONITOR DESCRIPTION

Sensor Voltage Detection Monitor

Under the air fuel ratio feedback control, if the air fuel ratio sensor voltage output indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the air fuel ratio sensor. The ECM illuminates the MIL and stores a DTC.

Example:

If the air fuel ratio sensor voltage output is below 2.8 V (very rich condition) and heated oxygen sensor output voltage below 0.69 V for 5 seconds, the ECM stores DTC P2196. Alternatively, if the air fuel ratio sensor voltage output is higher than 3.8 V (very lean condition) and heated oxygen sensor output voltage 0.21 V or more for 5 seconds, 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).

MONITOR STRATEGY

Related DTCs	P2195: Air Fuel Ratio Sensor (Bank 1 Sensor 1) Signal Stuck Lean P2196: Air Fuel Ratio Sensor (Bank 1 Sensor 1) Signal Stuck Rich
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	5 seconds: Sensor voltage detection monitor 3 seconds: Sensor current detection monitor
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

ALL

Monitor runs whenever following DTCs not stored

P0016 (VVT System - Misalignment)

P0017 (Exhaust VVT System - Misalignment)

P0031, P0032, P101D (Air Fuel Ratio Sensor Heater)

P0102, P0103 (Mass Air Flow Sensor)

P0112, P0113 (Intake Air Temperature Sensor)

P0115, P0117, P0118 (Engine Coolant Temperature Sensor)

P0125 (Insufficient Coolant Temperature for Closed Loop Fuel Control)

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle Position Sensor)

P0128 (Thermostat)

P0171, P0172 (Fuel System)

P0300 - P0304 (Misfire)

P0335 (Crankshaft Position Sensor)

P0340 (Camshaft Position Sensor)

P0451, P0452, P0453 (EVAP System)

P0500 (Vehicle Speed Sensor)

P0505 (IAC Valve)

P219A, P219C, P219D, P219E, P219F (Air Fuel Ratio Imbalance)

Sensor Voltage Detection Monitor (P2195, P2196):

Time after engine start	30 seconds or more
Air fuel ratio sensor status	Activated
Fuel system status	Closed loop

Sensor Current Detection Monitor (P2195, P2196):

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

Sensor Voltage Detection Monitor (Lean Side Malfunction P2195):

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

Sensor Voltage Detection Monitor (Rich Side Malfunction P2196):

Rear heated oxygen sensor voltage	Below 0.69 V
Air fuel ratio sensor voltage	Below 2.8 V

Sensor Current Detection Monitor (High Side Malfunction P2195):

Duration of following condition	3 seconds or more
Air fuel ratio sensor current	2.2 mA or higher

Sensor Current Detection Monitor (Low Side Malfunction P2196):

Duration of following condition	3 seconds or more
Air fuel ratio sensor current	Below 0.7 mA

MONITOR RESULT

Refer to Checking Monitor Status (See page
).

CONFIRMATION DRIVING PATTERN

This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page ).

Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on.
Start the engine, and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [A].
On the Techstream, enter the following menus to check the fuel-cut status: Powertrain / Engine / Data List / Idle Fuel Cut.
Drive the vehicle at 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.
Shift the transmission to S position [C].
Accelerate the vehicle to 64 km/h (40 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 4 seconds without depressing the brake pedal in order to execute fuel-cut control [E].
HINT:

Fuel-cut is performed when the following conditions are met:
- Accelerator pedal is fully released.
- Engine speed is 1400 rpm or more (fuel injection restart engine speed).
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.
HINT:
- 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 or P2196.

Check the DTC judgment result.

Techstream 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

HINT:

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].

If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page ).
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
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

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

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

HINT:

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

2.	CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST

(a) Has the vehicle run out of fuel in the past?

GO TO STEP 4

YES

3.	CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(i) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(j) Input the DTC: P2195 or P2196.

(k) Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTC is not output)	A
ABNORMAL (DTC P2195 or P2196 is output)	B

DTC CAUSED BY RUNNING OUT OF FUEL

4.	READ VALUE USING TECHSTREAM (TEST VALUE OF AIR FUEL RATIO SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Drive the vehicle in accordance with the drive pattern described in the Confirmation Driving Pattern.

(g) Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Current.

(h) Check that the status of O2 Sensor is Complete. If the status is still Incomplete, drive the vehicle according to the driving pattern again.

(i) Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details / RANGE B1S1.

(j) Check the test value of the air fuel ratio sensor output current during fuel cut.

Result	Proceed to
Within normal range (0.7 mA or higher, and below 2.2 mA)	A
Outside normal range (Below 0.7 mA, or 2.2 mA or higher)	B

GO TO STEP 14

5.	READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(d) Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume / AFS Voltage B1S1 and O2S B1S2.

(f) Perform the Control the Injection Volume operation with the engine idling.

(g) Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the Techstream.

HINT:

Change the fuel injection volume within the range of -12% to +12%. 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 sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

Techstream Display (Sensor)	Injection Volume	Status	Voltage
AFS Voltage B1S1 (Air fuel ratio)	+12%	Rich	Less than 3.1 V
AFS Voltage B1S1 (Air fuel ratio)	-12%	Lean	More than 3.4 V
O2S B1S2 (Heated oxygen)	+12%	Rich	More than 0.55 V
O2S B1S2 (Heated oxygen)	-12%	Lean	Less than 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	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.

HINT:

Refer to "Data List / Active Test" [AFS Voltage B1S1, O2S B1S2] (See page ).

GO TO STEP 14

6.	CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks (See page ).

OK:

No leaks in the intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system (See page ).

REPAIR OR REPLACE INTAKE SYSTEM

7.	CHECK EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks.

HINT:

Perform "Inspection After Repair" after repairing or replacing the exhaust system (See page ).

REPAIR OR REPLACE EXHAUST SYSTEM

8.	CHECK FUEL PRESSURE

(a) Check the fuel pressure (See page ).

GO TO STEP 16

9.	INSPECT FUEL INJECTOR ASSEMBLY

(a) Check the fuel injector assembly (whether fuel volume is high or low, and whether injection pattern is poor) (See page
).

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly (See page ).

REPLACE FUEL INJECTOR ASSEMBLY

10.	REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor (See page ).

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See page ).

11.	CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(i) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(j) Input the DTC: P2195 or P2196.

(k) Check the DTC judgment result.

Result

Result	Proceed to
ABNORMAL (DTC P2195 or P2196 is output)	A
NORMAL (DTC is not output)	B

END

12.	REPLACE ECM

(a) Replace the ECM (See page ).

13.	CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTC (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(i) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(j) Input the DTC: P2195 or P2196.

(k) Check the DTC judgment result.

Result

Techstream 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

END

14.	REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor (See page ).

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See page ).

15.	CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Turn the ignition switch to ON and turn the Techstream on.

(g) Start the engine and warm it up.

(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(i) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(j) Input the DTC: P2195 or P2196.

(k) Check the DTC judgment result.

Result

Result	Proceed to
NORMAL (DTC is not output)	A
ABNORMAL (DTC P2195 or P2196 is output)	B

END

REPLACE ECM

16.	CHECK FUEL LINE

(a) Check the fuel lines for leaks or blockage.

HINT:

Perform "Inspection After Repair" after replacing the fuel pump (See page ).

REPLACE FUEL PUMP

REPAIR OR REPLACE FUEL LINE

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