DTC P2195: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1); DTC P2196: Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1): Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P2195 or P2196 is output	A
   DTC P2195 or P2196 and other DTCs are output	B

   HINT: 

   If any DTCs other than P2195 and P2196 are output, troubleshoot those DTCs first.

B → See step   21 

A: Go to next step 

1. Has the vehicle run out of fuel in the past?

NO → See step   3 

YES → DTC CAUSED BY RUNNING OUT OF FUEL 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear DTCs. Refer to DTC CHECK / CLEAR .
5. Allow the vehicle to drive in accordance with the drive pattern described in the CONFIRMATION DRIVING PATTERN.
6. Enter the following menus: Powertrain / Engine and ECT / Monitor / O2 Sensor /Status2.
7. Check that the status2 of O2 Sensor is Complete.

   If the status is still Incomplete, perform the drive pattern increasing the vehicle speed and using the second gear to decelerate the vehicle.

8. Enter the following menus: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details / RANGE B1 S1.
9. Check the test value of the air fuel ratio sensor output current during fuel-cut.

   Result

   Result	Proceed to
   Within normal range (1.0 mA or higher, and below 3.6 mA)	A
   Outside normal range (Below 1.0 mA, or 3.6 mA or higher)	B

B → See step   18 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Turn the Techstream on.
4. Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.
5. Enter the following menus: Powertrain / Engine and ECT / Data List / AFS Voltage B1 S1 and Engine Speed, then press the Record button.
6. Check the air fuel ratio sensor voltage three times, when the engine is in each of the following conditions:
   • (1) While idling (check for at least 30 seconds)
   • (2) At an engine speed of approximately 2500 rpm (without any sudden changes in engine speed)
   • (3) Raise the engine speed to 4000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.

   Standard Voltage

   Condition	Air Fuel Ratio Sensor Voltage Variation	Reference
   (1) and (2)	Changes at approximately 3.3 V	Between 3.1 V and 3.5 V
   (3)	Increases to 3.8 V or higher	This occurs during engine deceleration (when fuel-cut performed)

   HINT: 

   For more information, see the diagrams below.

   Fig 1: Air Fuel Ratio Sensor Voltage And Engine RPM Chart

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT: 

   • If the output voltage of the air fuel ratio sensor remains at approximately 3.3 V (see Malfunction Condition diagram in the figure above. See Fig 1) under any conditions, including those above, the air fuel ratio sensor may have an open circuit. (This will also happen if the air fuel ratio sensor heater has an open circuit.)
   • If the output voltage of the air fuel ratio sensor remains at either approximately 3.8 V or higher, or below 2.8 V (see Malfunction Condition diagram in the figure above. See Fig 1) under any conditions, including those above, the air fuel ratio sensor may have a short circuit.
   • The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and results in a momentary increase in the air fuel ratio sensor output voltage.
   • The ECM must establish a closed throttle valve position learning value to perform fuel cut. If the battery terminal has been reconnected, the vehicle must be driven over 10 mph (16 km/h) to allow the ECM to learn the closed throttle valve position.
   • When the vehicle is driven:

     The output voltage of the air fuel ratio sensor may be below 2.8 V during fuel enrichment. For the vehicle, this translates to a sudden increase in speed with the accelerator pedal fully depressed when trying to overtake another vehicle. The air fuel ratio sensor is functioning normally.

   • The air fuel ratio sensor is a current output element; therefore, the current is converted into a voltage inside the ECM. Measuring the voltage at the connectors of the air fuel ratio sensor or ECM will show a constant voltage result.

NG → See step   10 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear DTCs.
5. Drive the vehicle referring the Confirmation Driving Pattern.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P2195 or P2196 is output	A
   DTC is not output	B

B → CHECK FOR INTERMITTENT PROBLEMS 

A: Go to next step 

1. Replace the air fuel ratio sensor. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear DTCs.
5. Drive the vehicle referring the Confirmation Driving Pattern.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC is not output	A
   DTC P2195 or P2196 is output	B

B → See step   22 

A → END 

NG → See step   23 

OK: Go to next step 

1. Disconnect the air fuel ratio sensor connector.
   Fig 2: Identifying ECM Connector And Air Fuel Ratio Sensor Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   B37-1 (HA1A) - B29-109 (HA1A)	Always	Below 1 Ω
   B37-3 (A1A+) - B29-112 (A1A+)
   B37-4 (A1A-) - B29-113 (A1A-)

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   B37-1 (HA1A) or B29-109 (HA1A) - Body ground	Always	10 kΩ or higher
   B37-3 (A1A+) or B29-112 (A1A+) - Body ground
   B37-4 (A1A-) or B29-113 (A1A-) - Body ground

4. Reconnect the air fuel ratio sensor connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM) 

OK: Go to next step 

1. Check the intake system for vacuum leak. Refer to ON-VEHICLE INSPECTION .

   OK

   No leaks from intake system.

NG → REPAIR OR REPLACE INTAKE SYSTEM 

OK: Go to next step 

1. Check the fuel pressure. Refer to ON-VEHICLE INSPECTION - Step 2 .

NG → REPAIR OR REPLACE FUEL SYSTEM 

OK: Go to next step 

1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor). Refer to INSPECTION .

NG → See step   24 

OK: Go to next step 

1. Replace the air fuel ratio sensor. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear DTCs.
5. Drive the vehicle referring the Confirmation Driving Pattern.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC is not output	A
   DTC P2195 or P2196 is output	B

B → See step   25 

A → END 

1. Replace the air fuel ratio sensor. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear DTCs.
5. Drive the vehicle referring the Confirmation Driving Pattern.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC is not output	A
   DTC P2195 or P2196 (Air fuel ratio sensor pending DTCs) is output	B

B → See step   26 

A → END