Inspection Procedure
WARNING: This page is about a different car, the 2007 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
HINT:
Intelligent tester only:
Malfunctioning areas can be identified by performing the A/F CONTROL function provided in the ACTIVE TEST. The A/F CONTROL function can help to determine whether the Air-fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the A/F CONTROL operation using the intelligent tester.
- Connect the intelligent tester to the DLC3.
- Start the engine and turn the tester ON.
- Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
- On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
- Perform the A/F CONTROL operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
- Monitor the output voltages of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2) displayed on the tester.
HINT:
- The A/F CONTROL 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
VOLTAGE REFERENCE
| Tester Display (Sensor) | Injection Volume | Status | Voltages |
|---|---|---|---|
| AFS B1 S1 (A/F) | +25 % | Rich | Less than 3.0 |
| -12.5 % | Lean | More than 3.35 | |
| O2S B1 S2 (HO2) | +25 % | Rich | More than 0.5 |
| -12.5% | Lean | Less than 0.4 |
NOTE:
The A/F sensor has an output delay of a few seconds and the HO2 sensor (sensor 2) output has a maximum output delay of approximately of 20 seconds.
AIR-FUEL RATIO SPECIFICATIONS
| Case | A/F Sensor (Sensor 1) Output Voltage | HO2 Sensor (Sensor 2) Output Voltage | Main Suspected Trouble Areas | ||
|---|---|---|---|---|---|
| 1 | Injection Volume +25 % -12.5 % | Injection Volume +25 % -12.5% | - | ||
| Output Voltage More than 3.35 V Less than 3.0 V | Output Voltage More than 0.5 V Less than 0.4 V | ||||
| 2 | Injection Volume +25 % -12.5% | Injection Volume +25 % -12.5 % |
|
||
| Output Voltage Almost no reaction | Output Voltage More than 0.5 V Less than 0.4 V | ||||
| 3 | Injection Volume +25 % -12.5 % | Injection Volume +25 % -12.5 % |
|
||
| Output Voltage More than 3.35 V Less than 3.0 V | Output Voltage Almost no reaction | ||||
| 4 | Injection volume +25 % -12.5 % | Injection Volume +25 % -12.5 % |
|
||
| Output Voltage Almost no reaction | Output Voltage Almost no reaction | ||||
Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1 S1 and O2S B1 S2, and press the YES button and then the ENTER button followed by the F4 button.
HINT:
- DTC P2A00 may be set 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 A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.
- 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 lean.
- CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)
- Connect an intelligent tester to the DLC3.
- Turn the ignition switch ON.
- Turn the tester ON.
- Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
- Read DTCs.
Result
RESULTDisplay (DTC Output) Proceed To P2195 or P2196 A P2195 or P2196 and other DTCs B HINT:
If any DTCs relating to the A/F sensor (DTCs for the A/F sensor heater or A/F sensor admittance) are output, troubleshoot those DTCs first.
B: GO TO DTC CHART
A: GO to next step
- READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF A/F SENSOR)
- Connect the intelligent tester to the DLC3.
- Turn the ignition switch ON and turn the tester ON.
- Clear DTCs (see DTC CHECK / CLEAR ).
- Drive the vehicle in accordance with the drive pattern described in the CONFIRMATION DRIVING PATTERN.
- Select the following menu items: DIAGNOSIS / ENHANCED OBD II / MONITOR INFO / MONITOR STATUS.
- Check that the status of O2S MON is COMPL.
If the status is still INCMPL, drive the vehicle according to the driving pattern again.
HINT:
- AVAIL indicates that the component has not been monitored yet.
- COMPL indicates that the component is functioning normally.
- INCMPL indicates that the component is malfunctioning.
- Select the following menu items: DIAGNOSIS / ENHANCED OBD II / MONITOR INFO / TEST RESULT / RANGE B1 S1; then press the ENTER button.
- Check the test value of the A/F sensor output current during fuel-cut.
Result
RESULTTest Value Proceed To Within normal range (1.0 mA or more, and less than 3.6 mA) A Outside normal range (Less than 1.0 mA, or 3.6 mA or more) B B: GO to step 12
A: GO to next step
- READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF A/F SENSOR)
- Connect the intelligent tester to the DLC3.
- Start the engine.
- Turn the tester ON.
- Warm up the A/F sensor at an engine speed of 2,500 rpm for 90 seconds.
- On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / SNAPSHOT / MANUAL SNAPSHOT / USER DATA / AFS B1 S1 and ENGINE SPD.
- Check the A/F sensor voltage 3 times, when the engine is in each of the following conditions:
- While idling (check for at least 30 seconds)
- At an engine speed of approximately 2,500 rpm (without any sudden changes in engine speed)
- Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.
Standard voltage
VOLTAGE SPECIFICATIONConditions A/F Sensor Voltage Variations Reference (1) and (2) Remains at approximately 3.3 V Between 3.1 V and 3.5 V (3) Increases to 3.8 V or more This occurs during engine deceleration (when fuel-cut performed) HINT:
- For more information, see the diagrams below.
- If the output voltage of the A/F sensor remains at approximately 3.3 V (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have an open circuit. (This will also happen if the A/F sensor heater has an open circuit.)
- If the output voltage of the A/F sensor remains at either approximately 3.8 V or more, or 2.8 V or less (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have a short circuit.
- The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and result in a momentary increase in the A/F 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 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 A/F 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 A/F sensor is functioning normally.
- The A/F 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 A/F sensor or ECM will show a constant voltage result.
NG: GO to step 9
OK: GO to next step
- PERFORM CONFIRMATION DRIVING PATTERN
- CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
- Read DTCs using the intelligent tester.
- Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
Result
RESULTDisplay (DTC Output) Proceed To P2195 or P2196 A No output B B: END
A: GO to next step
- REPLACE AIR-FUEL RATIO SENSOR
- PERFORM CONFIRMATION DRIVING PATTERN
- CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
- Read DTCs using the intelligent tester.
- Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
Result
RESULTDisplay (DTC Output) Proceed To No output A P2195 or P2196 B B: REPLACE ECM
A: END
- INSPECT AIR-FUEL RATIO SENSOR (HEATER RESISTANCE)
(see
INSPECTION PROCEDURE )
NG: REPLACE AIR-FUEL RATIO SENSOR
OK: GO to next step
- INSPECT INTEGRATION RELAY (EFI MAIN RELAY)
(see
INSPECTION )
NG: REPLACE INTEGRATION RELAY (EFI MAIN RELAY)
OK: GO to next step
- CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
- Disconnect the B7 A/F sensor connector.
- Turn the ignition switch ON.
- Measure the voltage between the +B terminal of the A/F sensor connector and body ground.
Standard voltage
TESTER CONNECTION SPECIFIED CONDITIONTester Connections Specified Conditions B7-2 (+B) - Body ground 9 to 14 V - Turn the ignition switch OFF.
- Disconnect the B30 ECM connector.
- Measure the resistance.
Standard resistance (Check for open)
TESTER CONNECTION SPECIFIED CONDITIONTester Connections Specified Conditions B7-1 (HA1A) - B30-109 (HA1A) Below 1 Ω B7-3 (A1A+) - B30-112 (A1A+) Below 1 Ω B7-4 (A1A-) - B30-113 (A1A-) Below 1 Ω Standard resistance (Check for short)
TESTER CONNECTION SPECIFIED CONDITIONTester Connections Specified Conditions B7-1 (HA1A) or B30-109 (HA1A) - Body ground 10 kΩ or higher B7-3 (A1A+) or B30-112 (A1A+) - Body ground 10 kΩ or higher B7-4 (A1A-) or B30-113 (A1A-) - Body ground 10 kΩ or higher - Reconnect the ECM connector.
- Reconnect the A/F sensor connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: GO to next step
- REPLACE AIR-FUEL RATIO SENSOR
- PERFORM CONFIRMATION DRIVING PATTERN
- CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)
- Read DTCs using the intelligent tester.
- Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.
Result
RESULTDisplay (DTC Output) Proceed To No output A P2195 or P2196 B B: REPLACE ECM
A: END