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 in an idling condition (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	Less than 3.1 V
AFS Voltage B1 S1 (Air fuel ratio)	-12.5%	Lean	More than 3.4 V
O2S B1 S2 (Heated oxygen)	+25%	Rich	More than 0.55 V
O2S B1 S2 (Heated oxygen)	-12.5%	Lean	Less than 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/AFS Voltage B1 S1 and O2S B1 S2; then press the graph button on the Data List screen.
NOTE: Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

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 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.
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.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)

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 P2195 or P2196 is output	A
DTC P2195 or P2196 and other DTCs are output	B

HINT:

If any DTCs other than P2195 and P2196 are output, troubleshoot those DTCs first.

B: GO TO DTC CHART

A: Go to next step

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
1. Has the vehicle run out of fuel in the past?
  NO: Go to step 3
  
  YES: DTC CAUSED BY RUNNING OUT OF FUEL

READ VALUE USING TECHSTREAM (TEST VALUE OF AIR FUEL RATIO SENSOR)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs (See DTC CHECK/CLEAR ).
Turn the ignition switch off.
Turn the ignition switch to ON and turn the Techstream on.
Allow the vehicle to drive in accordance with the drive pattern described in the CONFIRMATION DRIVING PATTERN .
Enter the following menus: Powertrain/Engine/Monitor/O2 Sensor.
Check that the Status 2 of O2 Sensor is Complete.
If the status is still Incomplete, perform the driving pattern increasing the vehicle speed and using second gear to decelerate the vehicle.
Enter the following menus: Powertrain/Engine/Monitor/O2 Sensor/Details/RANGE B1S1.

Check the test value of the air fuel ratio sensor output current during fuel-cut.

Result

RESULT CHART

Result	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 18

A: Go to next step

READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)

Connect the Techstream to the DLC3.
Start the engine.
Turn the Techstream on.
Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.
Enter the following menus: Powertrain/Engine/Data List/All Data/AFS Voltage B1 S1 and Engine Speed, then press the Record button.

Check the air fuel ratio sensor voltage three times, when the engine is in each of the following conditions:

While idling (check for at least 30 seconds) (step "A").
At an engine speed of approximately 2500 rpm (without any sudden changes in engine speed) (step "B").

Raise the engine speed to 4000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed (step "C").

Standard Voltage

AIR FUEL RATIO SENSOR REFERENCE

Condition	Air Fuel Ratio Sensor Voltage Variation	Reference
Step "A" and "B"	Changes at approximately 3.3 V	Between 3.1 V and 3.4 V
Step "C"	Increases to 3.8 V or higher	This occurs during engine deceleration (when fuel-cut performed)

HINT:

For more information, see the diagrams below.

Fig 1: Engine Speed And Air Fuel Ratio Sensor Voltage Malfunction Chart

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

If the output voltage of the air fuel ratio sensor remains at approximately 3.3 V (see Malfunction Condition 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.)
If the output voltage of the air fuel ratio sensor remains at either approximately 3.8 V or higher, or below 2.8 V (see Malfunction Condition diagram) under any conditions, including those above, the air fuel ratio sensor may have a short circuit.
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.
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 10 mph (16 km/h) to allow the ECM to learn the closed throttle valve position.
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.
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 result.
NG: Go to step 10

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 (See DTC CHECK/CLEAR ).
5. Turn the ignition switch off.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Start the engine and warm it up.
8. Drive the vehicle referring to the CONFIRMATION DRIVING PATTERN .

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Enter the following menus: Powertrain/Engine/Utility/All Readiness.
Input the DTC: P2195 or P2196.

Check the DTC judgment.

Result

RESULT CHART

Result	Proceed to
ABNORMAL (DTC P2195 or P2196 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 (See DTC CHECK/CLEAR ).
5. Turn the ignition switch off.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Start the engine and warm it up.
8. Drive the vehicle referring to the CONFIRMATION DRIVING PATTERN .

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Enter the following menus: Powertrain/Engine/Utility/All Readiness.
Input the DTC: P2195 or P2196.

Check the DTC judgment.

Result

RESULT CHART

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

B: REPLACE ECM (See REMOVAL )

A: REPAIR COMPLETED

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

Disconnect the air fuel ratio sensor connector.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
1 (HA1A) -2 (+B)	20°C (68°F)	1.8 to 3.4 Ω
1 (HA1A) - 4 (A1A-)	Always	10 kΩ or higher

Reconnect the air fuel ratio sensor connector.
NG: REPLACE AIR FUEL RATIO SENSOR (See REMOVAL )

Fig 2: Identifying Air Fuel Ratio Sensor Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to next step

CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)

Disconnect the air fuel ratio sensor connector.
Disconnect the ECM connector.

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

Standard Resistance (Check for Open)

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
B20-1 (HA1A) - B49-29 (HA1A)	Always	Below 1 Ω
B20-3 (A1A+) - B49-7 (A1A+)	Always	Below 1 Ω
B20-4 (A1A-) - B49-1 (A1A-)	Always	Below 1 Ω

Standard Resistance (Check for Short)

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
B20-1 (HA1A) or B49-29 (HA1A) - Body ground	Always	10 kΩ or higher
B20-3 (A1A+) or B49-7 (A1A+) - Body ground	Always	10 kΩ or higher
B20-4 (A1A-) or B49-1 (A1A-) - Body ground	Always	10 kΩ or higher

Reconnect the air fuel ratio sensor connector.
Reconnect the ECM connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR ECM)

Fig 3: Identifying Air Fuel Ratio Sensor And ECM Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to next step

CHECK INTAKE SYSTEM
1. Check the intake system for vacuum leaks (See ON-VEHICLE INSPECTION ).
  OK:
  
  No leaks in the intake system.
  
  NG: REPAIR OR REPLACE INTAKE SYSTEM
  
  OK
CHECK FUEL PRESSURE
1. Check the fuel pressure (See ON-VEHICLE INSPECTION ).
  NG: Go to step 21
  
  OK: Go to next step
INSPECT FUEL INJECTOR ASSEMBLY
1. Check the fuel injector assembly injection (whether fuel volume is high or low, and whether injection pattern is poor) (See INSPECTION ).
  NG: REPLACE FUEL INJECTOR ASSEMBLY (See REMOVAL )
  
  OK: 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 (See DTC CHECK/CLEAR ).
5. Turn the ignition switch off.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Start the engine and warm it up.
8. Drive the vehicle referring to the CONFIRMATION DRIVING PATTERN .

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Enter the following menus: Powertrain/Engine/Utility/All Readiness.
Input the DTC: P2195 or P2196.

Check the DTC judgment.

Result

RESULT CHART

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

B: REPLACE ECM (See REMOVAL )

A: REPAIR COMPLETED

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 (See DTC CHECK/CLEAR ).
5. Turn the ignition switch off.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Start the engine and warm it up.
8. Drive the vehicle referring to the CONFIRMATION DRIVING PATTERN .

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)

Enter the following menus: Powertrain/Engine/Utility/All Readiness.
Input the DTC: P2195 or P2196.

Check the DTC judgment.

Result

RESULT CHART

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

B: REPLACE ECM (See REMOVAL )

A: REPAIR COMPLETED

CHECK FUEL LINE
1. Check the fuel lines for leaks or blockage.
  NG: REPAIR OR REPLACE FUEL LINE
  
  OK: REPLACE FUEL PUMP (See REMOVAL )