Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

Hand-held tester only:

It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation. The A/F CONTROL operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble areas are malfunctioning or not.

Perform the ACTIVE TEST A/F CONTROL operation.
HINT:

The A/F CONTROL operation lowers the injection volume 12.5% or increases the injection volume 25%.
1. Connect the hand-held tester to the DLC3 on the vehicle.
2. Turn the ignition switch ON.
3. Warm up the engine by running the engine at 2,500 RPM for approximately 90 seconds.
4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
5. Perform the A/F CONTROL operation with the engine in an idle condition (press the right or left button).
  Result:
  
  A/F sensor reacts in accordance with increase and decrease of injection volume:
  
  +25 % --> RICH output: Less than 3.0 V
  
  -12.5 % --> LEAN output: More than 3.35 V
  
  Heated oxygen sensor reacts in accordance with increase and decrease of injection volume:
  
  +25 % --> RICH output: More than 0.55 V
  
  -12.5 % --> LEAN output: Less than 0.4 V

NOTE: The A/F sensor output has a few seconds of delay and the heated oxygen sensor output has about 20 seconds of delay at maximum.

Fig 1: A/F Sensor And Heated Oxygen Sensor Output Voltage Chart

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The following procedure of A/F CONTROL enables the user to check its output (show its graph indication) of A/F sensor and heated oxygen sensor.

To display the graph, enter ACTIVE TEST/ A/F CONTROL/USER DATA, then select "AFS B1S1 and O2S B1S2" or "AFS B2S1 and O2S B2S2" by pressing the "YES" button followed by the "ENTER" button and then the "F4" button.

HINT:

DTC P2A00 or P2A03 may be also detected, when the air-fuel ratio is stuck rich or lean.
A low A/F sensor voltage could be caused by a RICH air-fuel mixture. Check for conditions that would cause the engine to run with a RICH air-fuel mixture.
A high A/F sensor voltage could be caused by a LEAN air-fuel mixture. Check for conditions that would cause the engine to run with a LEAN air-fuel mixture.
Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

CHECK OTHER DTC OUTPUT (IN ADDITION TO A/F SENSOR DTC)
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Turn the ignition switch to ON and turn the hand-held tester or the OBD II scan tool ON.
3. Select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
4. Read the DTCs.
  Result:
  
  Fig 2: DTC Output Result Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:

If any other code besides P2A00 and/or P2A03 are output, perform troubleshooting for those DTCs first.

B: GO TO RELEVANT DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )

A: GO TO NEXT STEP.
READ VALUE OF OBD II SCAN TOOL OR HAND-HELD TESTER (OUTPUT VOLTAGE OF A/F SENSOR)
1. Connect the hand-held tester or the OBD II scan tool to the DLC 3.
2. Warm up the A/F sensors (bank 1, 2 sensor 1) by running the engine at 2,500 RPM for approximately 90 seconds.
3. Read A/F sensor voltage output on the OBD II scan tool or the hand-held tester.
4. Hand-held tester only:
  On the hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / SNAPSHOT / MANUAL SNAPSHOT / USER DATA. Read the values.
5. Select "AFS B1 S1 or AFS B2 S1 / ENGINE SPD" and press YES.
6. Monitor the A/F sensor voltage carefully.
7. Check the A/F sensor voltage output under the following conditions:
  1. Allow the engine to idle for 30 seconds.
  2. Run the engine at approximately 2,500 RPM. Do not suddenly change the RPM.
  3. Raise the engine speed to 4,000 RPM and quickly release the accelerator pedal so that the throttle is fully closed.
    Standard:
    
    Condition (1) and (2)
    
    Voltage change of 3.3 V (0.66 V) (*) (between approximately 3.1 to 3.5 V) as shown in the illustration.
    
    Condition (3)
    
    A/F sensor voltage increases to 3.8 V (0.76 V) (*) or more when fuel is cut during engine deceleration as shown in the illustration.
    
    (*) Voltage when using the OBD II scan tool.
  Fig 3: A/F Sensor Voltage And Engine RPM Chart (Normal And Malfunction Condition)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
- Whenever the A/F sensor output voltage remains at approximately 3.3 V (0.660 V) (*) (see "Malfunction Condition" graphic) under any condition as well as the above conditions, the A/F sensor may have an open-circuit. This will happen also when the A/F sensor heater has an open-circuit.
- Whenever the A/F sensor output voltage remains at a certain value of approximately 3.8 V (0.76 V) (*) or more, or 2.8 V (0.56 V) (*) or less (see "Malfunction Condition" graphic) under any condition as well as the above conditions, the A/F sensor may have a short-circuit.
- The ECM will stop fuel injection (fuel is cut) during engine deceleration. This will cause a LEAN condition and should result in a momentary increase in A/F sensor output voltage.
- The ECM must establish a closed throttle position learned value to perform fuel cut. If the battery cable was reconnected, the vehicle must be driven over 10 mph to allow the ECM to learn the closed throttle position.
- When the vehicle is driven:
  The output voltage of the A/F sensor may be below 2.8 V (0.76 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 A/F sensor is functioning normally.
- The A/F sensor is a current output element, and therefore the current is converted into voltage inside the ECM. If measuring voltage at connectors of A/F sensor or ECM, you will observe a constant voltage.
Voltage when using the OBD II scan tool.

OK: Go to step 11

NG: GO TO NEXT STEP.
INSPECT AIR FUEL RATIO SENSOR (RESISTANCE OF A/F SENSOR HEATER)
1. Disconnect the A10 or A11 A/F sensor connector.
2. Measure the resistance between the terminals of the A/F sensor.
  Standard:
  
  Fig 4: A/F Sensor Connector Terminals Specified Condition Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Reconnect the A/F sensor connector.
  
  Fig 5: Identifying A/F Sensor Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE AIR FUEL RATIO SENSOR

OK: GO TO NEXT STEP.
INSPECT AIR FUEL RATIO SENSOR HEATER RELAY
1. Remove the A/F sensor heater relay from the engine room R/B.
2. Check for continuity in the A/F sensor heater relay.
  Standard:
  
  Fig 6: A/F Sensor Heater Relay Terminals Continuity Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Reinstall the A/F sensor heater relay.
  
  Fig 7: Checking Continuity Between A/F Sensor Heater Relay Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE AIR FUEL RATIO SENSOR HEATER RELAY

OK: GO TO NEXT STEP.
CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
1. Disconnect the A10 or A11 A/F sensor connector.
2. Disconnect the E9 ECM connector.
3. Check the resistance between the wire harness side connectors.
  Standard (Check for open):
  
  Fig 8: A/F Sensor And ECM Terminals Specified Condition Chart (Check For Open)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard (Check for short):
  
  Fig 9: A/F Sensor And ECM Terminals Specified Condition Chart (Check For Short)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Reconnect the A/F sensor connector.
5. Reconnect the ECM connector.
  
  Fig 10: Identifying A/F Sensor Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 11: Disconnecting E9 ECM Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 12: A/F Sensor Heater Relay Reference Chart (Bank 1 Sensor 1)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: GO TO NEXT STEP.
CHECK AIR INDUCTION SYSTEM
1. Check for vacuum leaks in the air induction system.
NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK: GO TO NEXT STEP.
CHECK CONNECTION OF PCV HOSE
NG: REPAIR OR REPLACE PCV HOSE

OK: GO TO NEXT STEP.
CHECK FUEL PRESSURE (See ON-VEHICLE INSPECTION )
1. Check fuel pressure (High or low fuel pressure).
NG: REPAIR OR REPLACE FUEL SYSTEM

OK: GO TO NEXT STEP.
INSPECT FUEL INJECTOR ASSY (See INSPECTION )
1. Check injector injection (High or low fuel injection quantity or poor injection pattern).
NG: REPLACE FUEL INJECTOR ASSY (See FUEL INJECTOR ASSY (3MZ-FE) )

OK: GO TO NEXT STEP.
REPLACE AIR FUEL RATIO SENSOR
GO: GO TO NEXT STEP.
PERFORM CONFIRMATION DRIVING PATTERN (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) )
HINT:

Clear all DTCs prior to performing the confirmation driving pattern (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) ).

GO: GO TO NEXT STEP.
READ OUTPUT DTC (SEE IF A/F SENSOR DTC OUTPUT AGAIN)
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Turn the ignition switch to ON and turn the hand-held tester or the OBD II scan tool ON.
3. Select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
4. Read the DTCs.
  Result:
  
  Fig 13: DTC Output Result Table (1 Of 3)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
B: REPLACE ECM (See ECM (3MZ-FE) ) AND PERFORM CONFIRMATION DRIVING PATTERN (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) )

A: GO TO NEXT STEP.
CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
NO: CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )

YES: GO TO NEXT STEP.

DTC IS CAUSED BY RUNNING OUT OF FUEL
PERFORM CONFIRMATION DRIVING PATTERN (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) )
HINT:

Clear all DTCs prior to performing the confirmation driving pattern (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) ).

GO: GO TO NEXT STEP.
READ OUTPUT DTC (SEE IF A/F SENSOR DTC OUTPUT AGAIN)
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Turn the ignition switch ON and push the hand-held tester or the OBD II scan tool main switch ON.
3. Select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
4. Read the DTCs.
  Result:
  
  Fig 14: DTC Output Result Table (2 Of 3)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
B: RESET MEMORY AND PERFORM CONFIRMATION DRIVING PATTERN (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) )

A: GO TO NEXT STEP.
REPLACE AIR FUEL RATIO SENSOR
GO: GO TO NEXT STEP.
PERFORM CONFIRMATION DRIVING PATTERN (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) )
HINT:

Clear all DTCs prior to performing the confirmation driving pattern (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) ).

GO: GO TO NEXT STEP.
READ OUTPUT DTC (SEE IF A/F SENSOR DTC OUTPUT AGAIN)
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Turn the ignition switch to ON and turn the hand-held tester or the OBD II scan tool ON.
3. Select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
4. Read the DTCs.
  Result:
  
  Fig 15: DTC Output Result Table (3 Of 3)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
B: REPLACE ECM (See ECM (3MZ-FE) ) AND PERFORM CONFIRMATION DRIVING PATTERN (See 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), DTC P2197 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1), DTC P2198 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 2 SENSOR 1) )

A: GO TO NEXT STEP.
CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
NO: CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )

YES: GO TO NEXT STEP.

DTC IS CAUSED BY RUNNING OUT OF FUEL