Inspection Procedure

WARNING: This page is about a different variant/trim than selected.

HINT:

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 sensor, heated oxygen 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 the Techstream.

Connect the Techstream to the DLC3.
Start the engine.
Turn the Techstream on.
Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
Enter the following menus: Powertrain/Engine/Active Test/Control the Injection Volume for A/F Sensor.
Perform the Active Test 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 B1 S1 and O2S B1 S2) displayed on the Techstream.

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 and decreases in the fuel injection volume.

VOLTAGE STATUS CHART

Techstream Display (Sensor)	Injection Volume	Status	Voltage
AFS Voltage B1 S1 (Air fuel ratio)	+25%	Rich	Below 3.1 V
AFS Voltage B1 S1 (Air fuel ratio)	-12.5%	Lean	Higher than 3.4 V
O2S B1 S2 (Heated oxygen)	+25%	Rich	Higher than 0.55 V
O2S B1 S2 (Heated oxygen)	-12.5%	Lean	Below 0.4 V

NOTE: The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

AIR FUEL RATIO SENSOR REFERENCE

Case	Air Fuel Ratio Sensor (Bank 1 Sensor 1) Output Voltage	Heated Oxygen Sensor (Bank 1 Sensor 2) Output Voltage	Main Suspected Trouble Area
1	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	-
2	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Air fuel ratio sensor Air fuel ratio sensor heater Air fuel ratio sensor circuit
3	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Heated oxygen sensor Heated oxygen sensor heater Heated oxygen sensor circuit
4	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Injector Fuel pressure Gas leak from exhaust system (Air fuel ratio extremely rich or lean)

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/Active Test/Control the Injection Volume for A/F Sensor/All Data/AFS Voltage B1 S1 and O2S B1 S2; and then press the graph button on the Data List view.

HINT:

DTC P2A00 may be also stored when the air fuel ratio is stuck at rich or lean.
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.
Read freeze frame data using the 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 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.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain/Engine/Trouble Codes.

Read the DTCs.

Result

RESULT CHART

Result	Proceed to
DTC P2A00 is output	A
DTC P2A00 and other DTCs are output	B

HINT:

If any DTCs other than P2A00 are output, troubleshoot those DTCs first.

B: GO TO DTC CHART

A: Go to next step

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) (See INSPECTION PROCEDURE )
NG: REPLACE AIR FUEL RATIO SENSOR (See REMOVAL )

OK: Go to next step
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM) (See INSPECTION PROCEDURE )
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step
PERFORM CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs.
5. Turn the ignition switch off.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Drive the vehicle in accordance with the driving pattern described in the CONFIRMATION DRIVING PATTERN .

CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)

Enter the following menus: Powertrain/Engine/Utility/All Readiness.
Input the DTC: P2A00.

Check the DTC judgment.

Result

RESULT CHART

Result	Proceed to
ABNORMAL (DTC P2A00 is output)	A
NORMAL (DTC is not output)	B

B: CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )

A: Go to next step

REPLACE AIR FUEL RATIO SENSOR
1. Replace the air fuel ratio sensor (See REMOVAL ).
PERFORM CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs.
5. Turn the ignition switch off.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Drive the vehicle in accordance with the driving pattern described in the CONFIRMATION DRIVING PATTERN .

CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)

Enter the following menus: Powertrain/Engine/Utility/All Readiness.
Input the DTC: P2A00.

Check the DTC judgment.

Result

RESULT CHART

Result	Proceed to
ABNORMAL (DTC P2A00 is output)	A
NORMAL (DTC is not output)	B

B: REPAIR COMPLETED

A: CHECK ENGINE TO DETERMINE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO (See INSPECTION PROCEDURE )