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HOMESERVICE MANUALSTOYOTA2009FJ CRUISER RWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROL SYSTEM - DTC P0010 - P0175DTC P0171 SYSTEM TOO LEAN (BANK 1); DTC P0172 SYSTEM TOO RICH (BANK 1); DTC P0174 SYSTEM TOO LEAN (BANK 2); DTC P0175 SYSTEM TOO RICH (BANK 2)INSPECTION PROCEDURE

2009 Toyota FJ Cruiser RWD

Inspection Procedure

2009 Toyota FJ Cruiser RWDSECTION 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 a Techstream.

Connect a 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.
Select the following menu items: Powertrain / Engine and ECT / 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 voltage outputs of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) 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 and decreases in the fuel injection volume.

Standard

STANDARD VOLTAGE

Tester Display (Sensor)	Injection Volumes	Status	Voltages
AFS B1S1 or AFS B2S1 (A/F)	+25 %	Rich	Less than 3.0
AFS B1S1 or AFS B2S1 (A/F)	-12.5%	Lean	More than 3.35
O2S B1S2 or O2S B2S2 (HO2)	+25 %	Rich	More than 0.55
O2S B1S2 or O2S B2S2 (HO2)	-12.5%	Lean	Less than 0.4

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.

OUTPUT DELAY

Case	A/F Sensor (Sensor 1) Output Voltage			HO2 Sensor (Sensor 2) Output Voltage			Main Suspected Trouble Area
1	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	-
1	Output Voltage	More than 3.35 V Less than 3.0 V	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Output Voltage	More than 0.55 V Less than 0.4 V	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	-
2	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	A/F sensor A/F sensor heater A/F sensor circuit
2	Output Voltage	Almost no reaction	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Output Voltage	More than 0.55 V Less than 0.4 V	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	A/F sensor A/F sensor heater A/F sensor circuit
3	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	HO2 sensor HO2 sensor heater HO2 sensor circuit
3	Output Voltage	More than 3.35 V Less than 3.0 V	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Output Voltage	Almost no reaction	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	HO2 sensor HO2 sensor heater HO2 sensor circuit
4	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Injection Volume	+25% -12.5%	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Fuel Injector Fuel pressure Gas leak from exhaust system (Air fuel ratio extremely rich or lean)
4	Output Voltage	Almost no reaction	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Output Voltage	Almost no reaction	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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, select the following menu items on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor / A/F Control System / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2, then press the graph button on the Data List view.

HINT:

Read freeze frame data using a Techstream. Freeze frame data record 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 DTC P0171, P0172, P0174OR P0175)

Connect a Techstream to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.

Read DTCs.

Result

RESULT REFERENCE

Display (DTC Output)	Proceed To
P0171, P0172, P0174 or P0175	A
P0171, P0172, P0174 or P0175 and other DTCs	B

HINT:

If any DTCs other than P0171, P0172, P0174 or P0175 are output, troubleshoot those DTCs first.

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

A: Go to next step

CHECK PCV HOSE CONNECTIONS
OK: PCV hose is connected correctly and is not damaged.

NG: REPAIR OR REPLACE PCV HOSE

OK: Go to Next Step
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leak.
  OK: No leak from air induction system.
NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK: Go to Next Step

PERFORM ACTIVE TEST USING TECHSTREAM (A/F CONTROL)

Connect a 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.
Select the following menu items: Powertrain / Engine and ECT / 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 voltage outputs of A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) 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 and decreases in the fuel injection volume.

Standard

STANDARD VOLTAGE

Tester Display (Sensor)	Injection Volumes	Status	Voltages
AFS B1S1 or AFS B2S1 (A/F)	+25 %	Rich	Less than 3.0
AFS B1S1 or AFS B2S1 (A/F)	-12.5%	Lean	More than 3.35
O2S B1S2 or O2S B2S2 (HO2)	+25 %	Rich	More than 0.55
O2S B1S2 or O2S B2S2 (HO2)	-12.5 %	Lean	Less than 0.4

Result:

RESULT REFERENCE

Status AFS B1S1 or AFS B2S1	Status O2SB1S2 or O2S B2S2	A/F Condition and A/F Sensor Condition	Misfires	Suspected Trouble Areas	Proceed To
Lean/Rich	Lean/Rich	Normal	-	-	C
Lean	Lean	Actual air-fuel ratio lean	May occur	PCV valve and hose PCV hose connections Fuel injector blockage Gas leak from exhaust system Air induction system Fuel pressure Mass Air Flow (MAF) meter Engine Coolant Temperature (ECT)sensor	A
Rich	Rich	Actual air-fuel ratio rich	-	Fuel injector leak or blockage Gas leak from exhaust Ignition system Fuel pressure MAF meter ECT sensor	A
Lean	Lean/Rich	A/F sensor malfunction	-	A/F sensor	B
Rich	Lean/Rich	A/F sensor malfunction	-	A/F sensor	B
Lean: During Control the Injection Volume for A/F sensor, the A/F sensor output voltage (AFS) is consistently more than 3.35 V, and the HO2 sensor output voltage (O2S) is consistently less than 0.4 V. Rich: During Control the Injection Volume for A/F sensor, the AFS is consistently less than 3.0 V, and the O2S is consistently more than 0.55 V. Lean/Rich: During Control the Injection Volume for A/F sensor of the ACTIVE TEST, the output voltage of the heated oxygen sensor alternates correctly.

B:Go to step 11

C:Go to step 15

A: Go to next step

READ VALUE USING TECHSTREAM (COOLANT TEMP)
1. Connect a Techstream to the DLC3.
2. Turn the ignition switch ON and turn the tester ON.
3. Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
4. Read the Coolant Temp twice, when the engine is both cold and warmed up.
  Standard: With cold engine: Same as ambient air temperature. With warm engine: 80°C to 100°C (176°C to 212°F).
NG: REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

OK: Go to Next Step
READ VALUE USING TECHSTREAM (MAF)
1. Read the values using a Techstream (MAF).
  NOTE:
  - Turn the ignition switch to OFF.
  - Perform the inspection with the vehicle indoors and on a level surface.
  - Perform the inspection of the mass air flow meter while it is installed in the air cleaner case (installed on the vehicle).
  - During the test, do not use the exhaust air duct to perform suction on the exhaust pipe.
  1. Connect a Techstream to the DLC3.
  2. Turn the ignition switch ON (do not start the engine).
  3. Turn the tester ON.
  4. Select the following menu items: Powertrain / Engine and ECT / Data List / MAF.
  5. Wait for 30 seconds, and read the values on the tester.
    Standard value:
    
    Less than 0.72 g/sec
2. Inspect the mass air flow meter.
  1. Remove the mass air flow meter (See REMOVAL ).
  2. Using a work light, check that the platinum filament (heater portion) in the mass air flow meter has no foreign matter attached.
    OK: No foreign matter attached
    
    Fig 1: Identifying Platinum Filament (Heater Portion) In Mass Air Flow Meter
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Reinstall the mass air flow meter (See INSTALLATION ).
NG: REPLACE MASS AIR FLOW METER (See REMOVAL )

OK: Go to Next Step
CHECK FUEL PRESSURE
1. Check the fuel pressure (See ON-VEHICLE INSPECTION ).
NG: REPAIR OR REPLACE FUEL SYSTEM

OK: Go to Next Step
CHECK EXHAUST GAS LEAK
OK: No gas leak.

NG: REPAIR OR REPLACE EXHAUST SYSTEM

OK: Go to Next Step
CHECK SPARK AND IGNITION
HINT:

If the spark plugs or ignition system malfunctions, engine misfire may occur. The misfire count can be read using a Techstream. Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 Misfire Rate (to Cylinder #6 Misfire Rate).

NG: REPAIR OR REPLACE IGNITION SYSTEM

OK: Go to Next Step
INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)
HINT:

If the fuel injectors malfunction, engine misfire may occur.

The misfire count can be read using a Techstream. Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 Misfire Rate (to Cylinder #6 Misfire Rate).

NG: REPLACE FUEL INJECTOR ASSEMBLY (See ON-VEHICLE INSPECTION )

OK: Go to Next Step

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

Disconnect the B31 or B33 A/F sensor connector.

Fig 2: Identifying B31 Or B33 A/F Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance (Bank 1 Sensor 1)

TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

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

Standard Resistance (Bank 2 Sensor 1)

TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

Tester Connections	Specified Conditions
HA2A (1)-+B (2)	1.8 Ω to 3.4 Ω at 20°C (68°F)
HA2A (1)-A2A- (4)	10 kΩ or higher

Reconnect the A/F sensor connector.

NG: REPLACE AIR FUEL RATIO SENSOR (See REMOVAL )

OK: Go to Next Step

INSPECT AIR FUEL RATIO SENSOR HEATER RELAY

Remove the A/F sensor heater relay from the engine room relay block.

Fig 3: Identifying EFI Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

Tester Connections	Specified Conditions
3-5	10 Ω or higher
3-5	Below 1 Ω When battery voltage applied to terminal 1 and 2

Reinstall the A/F sensor heater relay.

NG: REPLACE AIR FUEL RATIO SENSOR HEATER RELAY

OK: Go to Next Step

CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)

Disconnect the B31 or B33 A/F sensor connector.

Fig 4: Identifying B31 Or B33 A/F Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Turn the ignition switch ON.

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

Standard Voltage

TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

Tester Connections	Specified Conditions
+B (B33-2) - Body ground	11 to 14 V
+B (B31-2) - Body ground	11 to 14 V

Turn the ignition switch OFF.
Disconnect the B2 ECM connector.

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

Standard Resistance (Check for open)

TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

Tester Connections	Specified Conditions
HA1A (B33-1) - HA1A (B2-2)	Below 1 Ω
A1A+ (B33-3) - A1A+ (B2-22)
A1A- (B33-4) - A1A- (B2-30)
HA2A (B31-1) - HA2A (B2-1)
A2A+ (B31-3) - A2A+ (B2-23)
A2A- (B31-4) - A2A- (B2-31)

Standard Resistance (Check for short)

TESTER CONNECTIONS SPECIFIED CONDITIONS CHART

Tester Connections	Specified Conditions
HA1A (B33-1) or HA1A (B2-2) - Body ground	10 kΩ or higher
A1A+ (B33-3) or A1A+ (B2-22) - Body ground
A1A- (B33-4) or A1A- (B2-30) - Body ground
HA2A (B31-1) or HA2A (B2-1) - Body ground
A2A+ (B31-3) or A2A+ (B2-23) - Body ground
A2A- (B31-4) or A2A- (B2-31) - Body ground

Reconnect the ECM connector.
Reconnect the A/F sensor connector.

Fig 5: A/F Sensor - System Diagram (Bank 1 Sensor 1)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

REPLACE AIR FUEL RATIO SENSOR
1. Replace the A/F sensor (See REMOVAL ).
PERFORM CONFIRMATION DRIVING PATTERN

Fig 6: Identifying Vehicle Speed - Driving Pattern
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Connect a Techstream to the DLC3.
2. Turn the ignition switch ON and turn the tester ON.
3. Clear DTCs (See DTC CHECK/CLEAR ).
4. Switch the ECM from normal mode to check mode using the tester (See CHECK MODE PROCEDURE ).
5. Start the engine and warm it up with all the accessories switched OFF.
6. Drive the vehicle at between 38 mph and 75 mph (60 km/h and 120 km/h) and at an engine speed of between 1,400 rpm and 3,200 rpm for 3 to 5 minutes.
  HINT:
  
  If the system is still malfunctioning, the MIL will be illuminated during step (f).
  
  NOTE: If the conditions in this test are not strictly followed, no malfunction will be detected.

CHECK WHETHER DTC OUTPUT RECURS (DTC P0171, P0172, P0174 OR P0175)

Connect a Techstream to the DLC3.
Turn the ignition switch ON and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.

Read DTCS.

Result

RESULT REFERENCE

Display (DTC Output)	Proceed To
No output	A
P0171, P0172, P0174 or P0175	B

B: REPLACE ECM

A: Go to next step

END

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.