Inspection Procedure
HINT:
Techstream 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 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 Control the Injection Volume for A/F sensor operation using Techstream.
- Connect Techstream 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 Techstream, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F sensor.
- Perform the Control the Injection Volume for A/F sensor operation with the engine in an idling condition (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 or AFS B2 S1 and O2S B2 S2) 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 %.
- Each sensor reacts in accordance with increases in the fuel injection volume.FUEL INJECTION VOLUME REFERENCE
Tester Display (Sensor) Injection Volume Status Voltage AFS B1 S1 or AFS B2S1 (A/F) +25 % Rich Less than 3.0 V AFS B1 S1 or AFS B2S1 (A/F) -12.5% Lean More than 3.35 V O2S B1 S2 or O2S B2 S2 (HO2) +25 % Rich More than 0 55 V O2S B1 S2 or O2S B2 S2 (HO2) -12 5 % Lean Less than 0.4 V
NOTE:
The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum output delay of approximately 20 seconds.
A/F SENSOR OUTPUT VOLTAGE REFERENCE
| 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 55 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 55 V Less than 0 4V |
||||
| 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 Control the Injection Volume for A/F sensor procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
- To display the graph, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS B1 S1 or AFS B2 S1 and O2S B1 S2 or O2S B2 S2 then press the graph button on the Data List view.
HINT:
- DTC P2A00 or P2A03 may also be set, 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 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.
- Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (See FREEZE FRAME DATA ).
- CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00 AND/OR P2A03)
- Connect Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the tester on.
- Enter the following menus: Powertrain / Engine / Trouble Code.
- Read the DTCs.
Result
RESULT CHARTDisplay (DTC Output) Proceed to P2A00 and/or P2A03 A P2A00 and/or P2A03 and other DTCs B HINT:
If any DTCs other than P2A00 or P2A03 are output, troubleshoot those DTCs first.
B: GO TO DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )
A: Go to next step.
- INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
- Disconnect the B3 or B4 A/F sensor connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Bank 1 sensor 1)
TESTER CONNECTION SPECIFIED CONDITION CHARTTester Connection Condition Specified Condition HT (1) - +B (2) 20°C (68°F) 1.8 to 3.4 Ω HT (1) - AF- (4) - 10 kΩ or higher Standard Resistance (Bank 2 sensor 1)
TESTER CONNECTION SPECIFIED CONDITION CHARTTester Connection Condition Specified Condition HT (1) - +B (2) 20°C (68°F) 1.8 to 3.4 Ω HT (1) - AF- (4) - 10 kΩ or higher - Reconnect the A/F sensor connector.
NG: REPLACE AIR FUEL RATIO SENSOR (See REMOVAL )
OK: Go to next step.
- CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
- Disconnect the B3 and B4 A/F sensor connectors.
- Turn the engine switch on (IG).
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
TESTER CONNECTION SPECIFIED CONDITION CHARTTester Connection Specified Condition +B (B3-2) - Body ground 9 to 14 V +B (B4-2) - Body ground 9 to 14 V - Turn the engine switch off.
- Disconnect the B12 ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open)
TESTER CONNECTION SPECIFIED CONDITION CHARTTester Connection Specified Condition HT (B3-1) - HA1A (B12-86) Below 1 Ω AF+ (B3-3) - A1A+ (B12-93) Below 1 Ω AF- (B3-4) -A1A- (B12-116) Below 1 Ω HT (B4-1) - HA2A (B12-109) Below 1 Ω AF+ (B4-3) - A2A+ (B12-120) Below 1 Ω AF- (B4-4) - A2A- (B12-119) Below 1 Ω Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Standard Resistance (Check for short)
TESTER CONNECTION SPECIFIED CONDITION CHARTTester Connection Specified Condition HT (B3-1) or HA1A (B12-86) - Body ground 10 kΩ or higher AF+ (B3-3) or A1A+ (B12-93) - Body ground 10 kΩ or higher AF- (B3-4) or A1A- (B12-116) - Body ground 10 kΩ or higher HT (B4-1) or HA2A (B12-109) - Body ground 10 kΩ or higher AF+ (B4-3) or A2A+ (B12-120) - Body ground 10 kΩ or higher AF- (B4-4) or A2A- (B12-119) - Body ground 10 kΩ or higher - Reconnect the ECM connector.
- Reconnect the A/F sensor connectors.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step.
- PERFORM CONFIRMATION DRIVING PATTERN
- CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)
- Read the DTCs using Techstream.
- Enter the following menus: Powertrain / Engine / Trouble Code.
Result
RESULT CHARTDisplay (DTC Output) Proceed to P2A00 and/or P2A03 A No output B
B: REPLACE ECM (See REMOVAL )
A: Go to next step.
- REPLACE AIR FUEL RATIO SENSOR
- Replace the air fuel ratio sensor (See REMOVAL ).
- PERFORM CONFIRMATION DRIVING PATTERN
- CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)
- Read the DTCs using Techstream.
- Enter the following menus: Powertrain / Engine / Trouble Code.
Result
RESULT CHARTDisplay (DTC Output) Proceed to No output A P2A00 and/or P2A03 B
B: REPLACE ECM (See REMOVAL )
A: END