CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)
READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF AIR FUEL RATIO SENSOR)
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
INSPECT FUEL INJECTOR ASSEMBLY
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
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) |
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 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. The heat generated by the heater is conducted to the solid electrolyte through the alumina, thereby accelerating the sensor activation.
A three way catalytic converter is used in order to convert the carbon monoxide, hydrocarbons and nitrogen oxide into less harmful substances. To allow the three way catalytic converter to function effectively, it is necessary to keep the air fuel ratio of the engine near the stoichiometric air fuel ratio.
*: The value changes inside the ECM. Since the air fuel ratio sensor is a current output element, 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) are met for 10 seconds or more (2 trip detection logic): (a) The air fuel ratio sensor voltage is higher than 3.8 V. (b) The 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 (2 trip detection logic). |
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P2196 | Conditions (a) and (b) are met for 10 seconds or more (2 trip detection logic): (a) The air fuel ratio sensor voltage is below 2.8 V for 10 seconds. (b) The heated oxygen sensor voltage is below 0.6 V. |
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While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is below 0.78 mA (2 trip detection logic). |
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- HINT:
- When either of these DTCs is stored, check the air fuel ratio sensor output voltage using the intelligent tester. Enter the following menus: Powertrain / Engine and ECT / Data List / AFS Voltage B1S1.
- Short-term fuel trim values can also be read using the intelligent tester.
- The ECM maintains the voltages at the A1A+ and A1A- terminals of the ECM at a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the intelligent tester.
- If the air fuel ratio sensor is malfunctioning, the ECM stores DTC P2195 or P2196.
WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN
- This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.
- Connect the intelligent tester to the DLC3.
- Turn the ignition switch to ON.
- Turn the tester on.
- Clear the DTCs (RAV4_ACA30 RM000000PDK0AHX.html).
- Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher (Procedure "A").
- Using the intelligent tester check the fuel-cut status. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Idle Fuel Cut.
- Drive the vehicle at a speed between 60 km/h (38 mph) and 120 km/h (75 mph) for at least 10 minutes (Procedure "B").
- Shift the transaxle to 2nd gear (Procedure "C").
- Drive the vehicle at a proper vehicle speed to perform the fuel-cut operation (Procedure "D") (refer to the following hint).
- HINT:
- Fuel-cut is performed when the following conditions are met:
- The accelerator pedal fully is released.
- The engine speed is 2500 rpm or more (fuel injection resumes at 1000 rpm).
- Accelerate the vehicle to 64 km/h (40 mph) or more by depressing the accelerator pedal for at least 10 seconds (Procedure "E").
- Soon after performing Procedure "E" above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal in order to execute fuel-cut control (Procedure "F").
- Allow the vehicle to decelerate until the vehicle speed is less than 10 km/h (6 mph).
- Repeat steps from Procedure "C" through Procedure "F" above at least 3 times in one driving cycle.
- CAUTION:
- Strictly observe posted speed limits, traffic laws and road conditions when performing these driving patterns.
INSPECTION PROCEDURE
- NOTICE:
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
- HINT:
- Intelligent tester only:
- Malfunctioning areas can be identified by performing the "Control the Injection Volume for A/F Sensor" function provided in the Active Test. The "Control the Injection Volume for A/F Sensor" function can help determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.
- Connect the intelligent tester to the DLC3.
- Start the engine.
- Turn the tester on.
- Warm up the engine at an engine speed of 2500 rpm for approximately 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 for A/F Sensor" operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
- Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the tester.
- HINT:
- The "Control the Injection Volume for A/F Sensor" operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- The sensors react in accordance with increases and decreases in the fuel injection volume.
- Standard:
Tester Display
(Sensor)Injection Volume Status Voltage AFS Voltage B1S1
(Air fuel ratio sensor)+25% Rich Below 3.1 V -12.5% Lean Higher than 3.4 V O2S B1S2
(Heated oxygen sensor)+25% Rich Higher than 0.55 V -12.5% Lean Below 0.4 V
- NOTICE:
- The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor (sensor 2) output has a maximum output delay of approximately 20 seconds.
Case | Air Fuel Ratio Sensor Output Voltage | Heated Oxygen Sensor Output Voltage | Main Suspected Trouble Area |
1 | ![]() | ![]() | - |
2 | ![]() | ![]() |
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3 | ![]() | ![]() |
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4 | ![]() | ![]() |
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- Following the "Control the Injection Volume for A/F Sensor" procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.
- To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / View / AFS Voltage B1S1 and O2S B1S2.
- HINT:
- DTC P2A00 may be stored when the air fuel ratio is stuck rich or lean.
- Read freeze frame data using the intelligent tester. 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.
1.CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.
Read the DTCs.
Result Result Proceed to P2195 or P2196 is output A "P2195 or P2196" and "P0136, P0137 or P0138" are output A 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.
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A | |
2.READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF AIR FUEL RATIO SENSOR) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Clear the DTCs (RAV4_ACA30 RM000000PDK0AHX.html).
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / Monitor Status.
Check that the status of "O2 Sensor" is "Complete".
If the status is still "Incomplete", drive the vehicle according to the driving pattern again.- HINT:
- "Available" indicates that the component has not been monitored yet.
- "Complete" indicates that the component is functioning normally.
- "Incomplete" indicates that the component is malfunctioning.
Enter the following menus: Powertrain / Engine and ECT / Data List / AFS Current B1S1.
Check the test value of the air fuel ratio sensor output current during fuel-cut (refer to Monitor Driving Pattern 2 [Detail for "C" through "F"] in Confirmation Driving Pattern).
Test Value | Proceed to |
Within normal range (0.78 mA or higher, and below 3.6 mA) | A |
Outside normal range (Below 0.78 mA, or 3.6 mA or higher) | B |
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A | |
3.READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR) |
Connect the intelligent tester to the DLC3.
Start the engine.
Turn the tester 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 / Data List / AFS Voltage B1S1 and Engine Speed / Function / Snap Shot Record.
Check the air fuel ratio sensor voltage 3 times, once under each of the following conditions:
Engine idling (for at least 30 seconds) (Step "A").
Engine running at an engine speed of approximately 2500 rpm (without any sudden changes in engine speed) (Step "B").
Engine speed to raised 4000 rpm and then accelerator pedal quickly released so that throttle valve is fully closed (Step "C").
- Standard Voltage:
Condition A/F Sensor Voltage Variation Reference Step "A" and Step "B" Remains at approximately 3.3 V Between 3.1 V and 3.5 V Step "C" Increases to 3.8 V or higher Occurs during engine deceleration
(when fuel-cut performed)
- HINT:
- For more information, see the diagrams below.
- If the output voltage of the air fuel ratio sensor remains at approximately 3.3 V (see "Malfunctioning" diagram) 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 2.8 V or less (see "Malfunctioning" diagram) 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 learned value to perform fuel cut. If the battery cable has been disconnected and reconnected, the vehicle must be driven over 16 km/h (10 mph) 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.
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OK | |
4.PERFORM CONFIRMATION DRIVING PATTERN |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Clear the DTCs (RAV4_ACA30 RM000000PDK0AHX.html).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the intelligent tester on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
NEXT | |
5.CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196) |
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2195 or P2196.
Check the DTC judgment result.
Result Result Proceed to ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) A NORMAL (DTC is not output) B
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A | |
6.REPLACE AIR FUEL RATIO SENSOR |
Replace the air fuel ratio sensor (RAV4_ACA30 RM000001RO300SX.html).
NEXT | |
7.PERFORM CONFIRMATION DRIVING PATTERN |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Clear the DTCs (RAV4_ACA30 RM000000PDK0AHX.html).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the intelligent tester on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
NEXT | |
8.CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196) |
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2195 or P2196.
Check the DTC judgment result.
Result Result Proceed to ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) A NORMAL (DTC is not output) B
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A | ||
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9.CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST |
Has the vehicle run out of fuel in the past?
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YES | ||
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10.INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) |
Inspect the air fuel ratio sensor (RAV4_ACA30 RM000001Z1P00UX_01_0001.html).
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OK | |
11.CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM) |
Disconnect the air fuel ratio sensor connector.
Disconnect the ECM connector.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition B7-2 (+B) - Body ground Ignition switch ON 11 to 14 V
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection Condition Specified Condition B7-1 (HA1A) - B32-109 (HA1A) Always Below 1 Ω B7-3 (A1A+) - B32-112 (A1A+) Always Below 1 Ω B7-4 (A1A-) - B32-113 (A1A-) Always Below 1 Ω
- Standard Resistance (Check for Short):
Tester Connection Condition Specified Condition B7-1 (HA1A) or B32-109 (HA1A) - Body ground Always 10 kΩ or higher B7-3 (A1A+) or B32-112 (A1A+) - Body ground Always 10 kΩ or higher B7-4 (A1A-) or B32-113 (A1A-) - Body ground Always 10 kΩ or higher
Reconnect the ECM connector.
Reconnect the air fuel ratio sensor connector.
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OK | |
12.CHECK INTAKE SYSTEM |
Check the intake system for vacuum leakage.
- OK:
- No leakage from intake system.
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OK | |
13.CHECK FUEL PRESSURE |
Check the fuel pressure (RAV4_ACA30 RM000000QE3013X_02_0005.html).
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OK | |
14.INSPECT FUEL INJECTOR ASSEMBLY |
Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (RAV4_ACA30 RM000000VZW010X_01_0001.html).
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OK | |
15.REPLACE AIR FUEL RATIO SENSOR |
Replace the air fuel ratio sensor (RAV4_ACA30 RM000001RO300SX.html).
NEXT | |
16.PERFORM CONFIRMATION DRIVING PATTERN |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Clear the DTCs (RAV4_ACA30 RM000000PDK0AHX.html).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the intelligent tester on.
Start the engine and warm it up.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
NEXT | |
17.CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196) |
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2195 or P2196.
Check the DTC judgment result.
Result Result Proceed to ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) A NORMAL (DTC is not output) B
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A | ||
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