Dtc P2195 Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)

DESCRIPTION

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

INSPECTION PROCEDURE

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)

REPLACE AIR FUEL RATIO SENSOR

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)

CHECK AIR INDUCTION SYSTEM

CHECK FUEL PRESSURE

INSPECT FUEL INJECTOR ASSEMBLY

REPLACE AIR FUEL RATIO SENSOR

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

DESCRIPTION

HINT:

1. Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.
   
2. Sensor 1 refers to the sensor mounted in front of the three way catalytic converter and located near the engine assembly.
   

HINT:

1. 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.
   
2. Short-term fuel trim values can also be read using the intelligent tester.
   
3. 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.
   
4. If the air fuel ratio sensor is malfunctioning, the ECM stores DTC P2195 or P2196.
   

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

1. This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.
   
   
   
   
   
   
1. Connect the intelligent tester to the DLC3.
   
2. Turn the ignition switch to ON [A].
   
3. Turn the tester on.
   
4. Clear the DTCs (HILUX_TGN26 RM000000PDK12LX.html).
   
5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) [B].
   
6. Drive the vehicle at 60 km/h (37 mph) or more for 20 minutes or more [C].
   

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

   HINT:

   1. This step is performed to complete ethanol concentration learning.
      
   2. If DTC P0136, P2195 or P2196 is output when any of the following conditions is met, it is necessary to complete ethanol concentration learning to meet preconditions.
      
   1. The battery has been disconnected and reconnected.
      
   2. The DTCs have been cleared.
      
   3. Both fuel tank assemblies (for main and sub tanks) have been filled with fuel.
      
7. Drive the vehicle at more than 40 km/h (25 mph) for 20 seconds or more [D].
   

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

8. Allow the engine to idle for 30 seconds or more [E].
   
9. Repeat procedure [D] and [E] described above at least 3 times.
   
10. Allow the engine to idle for 40 seconds or more [F].
    
11. Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
    
12. Read the pending DTCs.
    

    HINT:

    If a pending DTC is output, the system is malfunctioning.

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.

1. Connect the intelligent tester to the DLC3.
   
2. Start the engine.
   
3. Turn the tester on.
   
4. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
   
5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
   
6. 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).
   
7. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the tester.
   

HINT:

1. 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%.
   
2. 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)	+12.5%	Rich	Below 3.1 V
	-12.5%	Lean	Higher than 3.4 V
O2S B1S2 (Heated oxygen sensor)	+12.5%	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 (Sensor 1) Output Voltage	Heated Oxygen Sensor (Sensor 2) Output Voltage	Main Suspected Trouble Area
1			-
2			Air fuel ratio sensor Air fuel ratio sensor heater Air fuel ratio sensor circuit
3			Heated oxygen sensor Heated oxygen sensor heater Heated oxygen sensor circuit
4			Fuel injector assembly Fuel pressure Gas leak from exhaust system (air-fuel ratio extremely rich or lean)

1. 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.
   
2. 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:

1. 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.
   
2. 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.
   
3. 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. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the tester on.
   

4. Enter the following menus: Powertrain / Engine and ECT / DTC.
   

5. 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.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the tester on.
   

4. Clear the DTCs (HILUX_TGN26 RM000000PDK12LX.html).
   

5. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
   

6. Enter the following menus: Powertrain / Engine and ECT / Utility / Monitor Status.
   

7. 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:

   1. "Available" indicates that the component has not been monitored yet.
      
   2. "Complete" indicates that the component is functioning normally.
      
   3. "Incomplete" indicates that the component is malfunctioning.
      

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

9. 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).
   

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine.
   

3. Turn the tester 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 B1S1 and Engine Speed / Function / Snap Shot Record.
   

6. Check the air fuel ratio sensor voltage 3 times, once under each of the following conditions:
   

   1. Engine idling (for at least 30 seconds) (Step "A").
      

   2. Engine running at an engine speed of approximately 2500 rpm (without any sudden changes in engine speed) (Step "B").
      

   3. 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:

1. For more information, see the diagrams below.
   
   
   
   
   
   
2. 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).
   
3. 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.
   
4. 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.
   
5. 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.
   
6. 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.
   
7. 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.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the intelligent tester on.
   

4. Clear the DTCs (HILUX_TGN26 RM000000PDK12LX.html).
   

5. Turn the ignition switch off and wait for at least 30 seconds.
   

6. Turn the ignition switch to ON and turn the intelligent tester on.
   

7. Start the engine and warm it up.
   

8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
   

1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
   

2. Input the DTC: P2195 or P2196.
   

3. Check the DTC judgment result.
   
   

   Result

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

1. Replace the air fuel ratio sensor (HILUX_TGN26 RM00000142300ZX.html).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the intelligent tester on.
   

4. Clear the DTCs (HILUX_TGN26 RM000000PDK12LX.html).
   

5. Turn the ignition switch off and wait for at least 30 seconds.
   

6. Turn the ignition switch to ON and turn the intelligent tester on.
   

7. Start the engine and warm it up.
   

8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
   

1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
   

2. Input the DTC: P2195 or P2196.
   

3. Check the DTC judgment result.
   
   

   Result

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

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

1. Inspect the air fuel ratio sensor (HILUX_TGN26 RM000001421010X.html).
   

1. Disconnect the air fuel ratio sensor connector.
   

2. Disconnect the ECM connector.
   

3. Measure the voltage according to the value(s) in the table below.
   

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   C85-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

4. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance (Check for Open):

   Tester Connection	Condition	Specified Condition
   C85-1 (HA1A) - C97-6 (HA1A)	Always	Below 1 Ω
   C85-3 (A1A+) - C97-7 (A1A+)	Always	Below 1 Ω
   C85-4 (A1A-) - C97-1 (A1A-)	Always	Below 1 Ω

   Standard Resistance (Check for Short):

   Tester Connection	Condition	Specified Condition
   C85-1 (HA1A) or C97-6 (HA1A) - Body ground	Always	10 kΩ or higher
   C85-3 (A1A+) or C97-7 (A1A+) - Body ground	Always	10 kΩ or higher
   C85-4 (A1A-) or C97-1 (A1A-) - Body ground	Always	10 kΩ or higher

5. Reconnect the ECM connector.
   

6. Reconnect the air fuel ratio sensor connector.
   

   
   
   
   

1. Check the air induction system for vacuum leakage.
   

   OK:

   No leakage from air induction system.
   

1. Check the fuel pressure (HILUX_TGN26 RM000000YL704QX_01_0002.html).
   

1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (HILUX_TGN26 RM000000YL901AX.html).
   

1. Replace the air fuel ratio sensor (HILUX_TGN26 RM00000142300ZX.html).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the intelligent tester on.
   

4. Clear the DTCs (HILUX_TGN26 RM000000PDK12LX.html).
   

5. Turn the ignition switch off and wait for at least 30 seconds.
   

6. Turn the ignition switch to ON and turn the intelligent tester on.
   

7. Start the engine and warm it up.
   

8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
   

1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
   

2. Input the DTC: P2195 or P2196.
   

3. Check the DTC judgment result.
   
   

   Result

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