Engine Controls - System/component Tests - V6 & V8: Other Toyota Avalon XX10 рестайлинг

ELECTRONIC THROTTLE CONTROL SYSTEM (ETCS)

Note. The ETCS may also be referred to as the Electronic Throttle Control System-Intelligent (ETCS-I or ETCS-i).

Land Cruiser & LX470

For testing of throttle body and components, see THROTTLE BODY under IDLE CONTROL SYSTEM.

INTAKE AIR CONTROL VALVE SYSTEM

Note. Intake Air Control Valve (IACV) system may also be referred to as Acoustic Control Induction System (ACIS).

Scheme 69

Scheme 70

1. Using 3-way connector, connect vacuum gauge in vacuum line to actuator valve. (Scheme 69) Actuator valve is located at end of air intake chamber. Start engine. With engine idling, ensure no vacuum reading is obtained.
2. Fully open throttle and ensure vacuum reading momentarily reads approximately 8 in. Hg and actuator valve rod pulls inward. If actuator valve rod pulls inward, system is operating correctly. If actuator valve rod does not pull inward, proceed to next step.
3. Disconnect vacuum hose from actuator valve. Using vacuum pump, apply 8 in. Hg of vacuum to actuator valve. Ensure actuator valve rod pulls inward and remains pulled inward for at least one minute. Replace actuator valve if defective. If actuator valve operates correctly, reconnect vacuum hose. Proceed to next step.
4. Disconnect hoses from vacuum tank. Vacuum tank is located near driver's side front corner of engine compartment, below battery tray. Apply air pressure to port "B" on vacuum tank. Ensure air flows from port "A". Perform STEP 1. (Scheme 70) Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2. (Scheme 70)
5. Plug port "B" on vacuum tank. Using vacuum pump, apply 8 in. Hg of vacuum to port "A". Perform STEP 3. (Scheme 70) Ensure vacuum reading will hold for at least one minute. Replace vacuum tank if defective and recheck system operation. If vacuum tank is okay, reconnect vacuum hoses. Proceed to next step.
6. Remove "V" bank cover located on top of engine. (Scheme 71)-4. Disconnect electrical connector and vacuum hoses from intake air control valve Vacuum Switching Valve (VSV). (Scheme 71)-4. NOTE: It may be necessary to remove emission control valve set which contains various vacuum switching valves for access to intake air control valve VSV.
7. Using ohmmeter, check that continuity exists between electrical terminals on intake air control valve VSV and that resistance is 33-39 ohms at 68°F (20°C). Replace intake air control valve VSV if no continuity exists or resistance is not within specification.
8. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of intake air control valve VSV. Replace intake air control valve VSV if continuity exists between electrical terminal and body of intake air control valve VSV.
9. Apply air pressure to port "B" on intake air control valve VSV. Ensure air flows from the filter. Perform STEP 1. (Scheme 73) Apply battery voltage and ground to electrical terminals on intake air control valve VSV. Apply air pressure to port "B" on intake air control valve VSV. Ensure air flows from port "A" and not from the filter. Perform STEP 2. (Scheme 73) Replace intake air control valve VSV if defective. Recheck system operation.
10. If intake air control valve VSV is okay, reinstall VSV. Remove glove box for access to Engine Control Module (ECM). Turn ignition on. Using voltmeter, check voltage between ground and ECM terminal ACIS (Red/Yellow wire). (Scheme 74)and (Scheme 75). This is the wire from intake air control valve VSV to the ECM. NOTE: For additional identification of ECM terminals, see PIN VOLTAGE CHART S article.
11. Voltage should be 9-14 volts. If voltage is within specification, substitute another ECM and recheck system operation. If voltage is not within specification, check for defective EFI main relay or wiring harness between EFI main relay and ECM. See «EFI MAIN RELAY»(ref-95583-S17143643002001040200000) under MOTORS & RELAYS. See appropriate wiring diagram in WIRING DIAGRAMS article.

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

Power & Ground Circuits

For testing of Engine Control Module (ECM) power and ground circuits, see PIN VOLTAGE CHART S article. See ECM LOCATION table for identifying ECM mounting locations.

ECM LOCATION

For testing of accelerator pedal position sensor, see THROTTLE BODY under IDLE CONTROL SYSTEM.

Avalon Calif. Emission Vehicles & Camry Calif. Emission Vehicles With A/T

1. Two heated A/F sensors are used, one on each exhaust manifold. Heated A/F sensor on rear (firewall side) exhaust manifold may be referred to as bank No. 1 sensor No. 1. Heated A/F sensor on front (radiator side) exhaust manifold may be referred to as bank No. 2 sensor No. 1.
2. To check the heater resistance on A/F sensor, disconnect electrical connector at A/F sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 76) Replace the A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C).
3. If problem exists in A/F sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

Scheme 76

AIRFLOW METER

Note. Airflow meter may be referred to as Mass Airflow (MAF) meter.

Avalon, Camry & Sienna

1. Turn ignition off. Disconnect electrical connector from airflow meter. Airflow meter is bolted to the side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter and note airflow meter terminal identification. (Scheme 77)-11.
2. Using ohmmeter, check resistance between terminals E2 and THA. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-95583-S20638539122001040200000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on the airflow meter with electrical connector installed. (Scheme 80)-14.
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 80)-14. While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter.

1. Turn ignition off. Disconnect electrical connector from airflow meter. Airflow meter is bolted to the top side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter and note airflow meter terminal identification. (Scheme 77)-11.
2. Using ohmmeter, check resistance between terminals E2 and THA. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-95583-S20638539122001040200000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on the airflow meter with electrical connector installed. (Scheme 80)-14.
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 80)-14. While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter.

Tacoma, T100 & 4Runner

1. Turn ignition off. Disconnect electrical connector from airflow meter. Airflow meter is located between air intake hose and upper cap on air cleaner assembly. Remove airflow meter and note airflow meter terminal identification. (Scheme 77)-11.
2. Using ohmmeter, check resistance between terminals E2 and THA. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-95583-S20638539122001040200000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on the airflow meter with electrical connector installed. (Scheme 80)-14.
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 80)-14. While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter.

AIRFLOW METER RESISTANCE

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Avalon & Land Cruiser & LX470

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on the brakelight switch. (Scheme 83)-16.
2. Using ohmmeter, check that continuity exists between terminals No. 1 and 2 with brake pedal depressed. Check that no continuity exists between terminals No. 1 and 2 with brake pedal released.
3. Check that no continuity exists between terminals No. 3 and 4 with brake pedal depressed. Check that continuity exists between terminals No. 3 and 4 with brake pedal released. Adjust or replace brakelight switch if operation is not as described.

Camry, Sienna, Tacoma, T100 & 4Runner

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of the brake pedal. Note terminal identification on brakelight switch. (Scheme 83)-16.
2. On models without cruise control, use ohmmeter to check that no continuity exists between terminals No. 1 and 2 with brake pedal released. Check that continuity exists between terminals No. 1 and 2 with brake pedal depressed. Adjust or replace brakelight switch if operation is not as described.
3. On models with cruise control, use ohmmeter to check that no continuity exists between terminals No. 1 and 2 with brake pedal released. Check that continuity exists between terminals No. 1 and 2 with brake pedal depressed.
4. Check that no continuity exists between terminals No. 3 and 4 with brake pedal depressed. Check that continuity exists between terminals No. 3 and 4 brake pedal released. Adjust or replace brakelight switch if operation is not as described.

Scheme 83

Scheme 84

CAMSHAFT POSITION SENSOR

For testing camshaft position sensor, see appropriate BASIC TESTING article.

CRANKSHAFT POSITION SENSOR

For testing crankshaft position sensor, see appropriate BASIC TESTING article.

Avalon & Camry

1. Manufacturer recommends removing throttle body for access to EGR gas temperature sensor. See appropriate REMOVE/INSTALL/OVERHAUL article. Remove EGR gas temperature sensor. EGR gas temperature sensor is screwed into bottom of pipe that EGR valve is mounted on.
2. Place threaded end of EGR gas temperature sensor and thermometer in container of oil. Attach ohmmeter between electrical terminals on EGR gas temperature sensor.
3. Heat oil and note resistance at specified temperature. See «EGR GAS TEMPERATURE SENSOR RESISTANCE»(ref-95583-S21443730662001040200000) table. Replace EGR gas temperature sensor if resistance is not within specification. Reinstall EGR gas temperature sensor.

Tacoma 2WD All Models & 4WD Regular Cab, & T100 2WD 1/2 Ton

1. Remove EGR gas temperature sensor. EGR gas temperature sensor is screwed into side of EGR valve.
2. Place threaded end of EGR gas temperature sensor and thermometer in container of oil. Attach ohmmeter between electrical terminals on EGR gas temperature sensor.
3. Heat oil and note resistance at specified temperature. See «EGR GAS TEMPERATURE SENSOR RESISTANCE»(ref-95583-S21443730662001040200000) table. Replace EGR gas temperature sensor if resistance is not within specification. Reinstall EGR gas temperature sensor.

EGR GAS TEMPERATURE SENSOR RESISTANCE

For testing of EGR position sensor, see EGR POSITION SENSOR under EMISSION SYSTEMS & SUB-SYSTEMS .

1. Ensure ignition is off. Note location of ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-95583-S35681385472001040200000) table. Remove ECT sensor. See appropriate REMOVE/INSTALL/OVERHAUL article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 85) Replace ECT sensor if resistance is not within specification.
3. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Fill cooling system.

1. Note location of ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-95583-S35681385472001040200000) table. Manufacturer recommends removing throttle body for access to ECT sensor. Remove ECT sensor. See appropriate REMOVE/INSTALL/OVERHAUL article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 85) Replace ECT sensor if resistance is not within specification.
3. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Install throttle body. Fill cooling system.

1. Note location of ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-95583-S35681385472001040200000) table. Manufacturer recommends removing upper timing belt cover and fuel crossover pipe for access to ECT sensor. Remove ECT sensor. See appropriate REMOVE/INSTALL/OVERHAUL article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 85) Replace ECT sensor if resistance is not within specification.
3. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Fill cooling system.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION

Scheme 85

For testing of fuel pump switch, see FUEL PUMP SWITCH (LAND CRUISER & LX470) under FUEL DELIVERY under FUEL SYSTEM.

HEATED OXYGEN SENSOR

Note. On Avalon Calif. emission vehicles and Camry Calif. emission vehicles with A/T, a heated oxygen sensor is used on exhaust pipe behind catalytic converter and a Air/Fuel (A/F) sensor is used on each exhaust manifold. For testing of the A/F sensor, see AIR/FUEL (A/F) SENSOR under ENGINE SENSORS & SWITCHES. On Avalon except Calif. emission vehicles and Camry except Calif. emission vehicles with A/T, a heated oxygen sensor is used on each oxygen manifold and on exhaust pipe, behind catalytic converter.

Avalon

1. Heated oxygen sensor on rear (firewall side) exhaust manifold may be referred to as bank No. 1 sensor No. 1. Heated oxygen sensor on front (radiator side) exhaust manifold may be referred to as bank No. 2 sensor No. 1. Heated oxygen sensor on the exhaust pipe behind catalytic converter may be referred to as bank No. 1 sensor No. 2.
2. To test the heater on the heated oxygen sensor, disconnect electrical connector from appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 86)and (Scheme 87) -20. NOTE: Electrical connector for heated oxygen sensor on exhaust pipe behind catalytic converter is located below passenger's side front seat, near center console on column shift models and contains a Dark Gray 4-pin electrical connector. On floor shift models, electrical connector is located on passenger's side, below carpet, near center console and contains a Dark Gray 4-pin electrical connector.
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 86)and (Scheme 87) -20. Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

Camry

1. Heated oxygen sensor on rear (firewall side) exhaust manifold may be referred to as bank No. 1 sensor No. 1. Heated oxygen sensor on front (radiator side) exhaust manifold may be referred to as bank No. 2 sensor No. 1. Heated oxygen sensor on the exhaust pipe behind catalytic converter may be referred to as bank No. 1 sensor No. 2.
2. To test the heater on the heated oxygen sensor, disconnect electrical connector from appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 86)and (Scheme 87) -20. NOTE: Electrical connector for heated oxygen sensor on exhaust pipe behind catalytic converter is located below driver's side front seat, below carpet near center console and contains a Dark Gray 4-pin electrical connector.
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 86)and (Scheme 87) -20. Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

Scheme 86

Scheme 87

Scheme 88

1. Four heated oxygen sensors are used, one on each exhaust manifold, and one on each exhaust pipe, behind catalytic converter. On driver's side, heated oxygen sensor on exhaust manifold may be referred to as bank No. 1 sensor No. 1, and heated oxygen sensor on exhaust pipe behind catalytic converter may be referred to as bank No. 1 sensor No. 2. On passenger's side, heated oxygen sensor on exhaust manifold may be referred to as bank No. 2 sensor No. 1, and heated oxygen sensor on exhaust pipe behind catalytic converter may be referred to as bank No. 2 sensor No. 2.
2. To test the heater on the heated oxygen sensor, disconnect electrical connector from appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 89)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 89) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

Scheme 89

Sienna

1. Three heated oxygen sensors are used, one on each exhaust manifold, and one on exhaust pipe, behind catalytic converter. Heated oxygen sensor on rear (firewall side) exhaust manifold may be referred to as bank No. 1 sensor No. 1. Heated oxygen sensor on front (radiator side) exhaust manifold may be referred to as bank No. 2 sensor No. 1. Heated oxygen sensor on exhaust pipe behind catalytic converter may be referred to as bank No. 1 sensor No. 2.
2. To test the heater on the heated oxygen sensor, disconnect electrical connector from appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 90)and (Scheme 91). NOTE: Electrical connector for heated oxygen sensor on exhaust pipe behind catalytic converter is located below passenger's side front seat, underneath the carpet and contains a Dark Gray 4-pin electrical connector.
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 90)and (Scheme 91). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

Scheme 90

Scheme 91

1. Two heated oxygen sensors are used, one on exhaust pipe in front of catalytic converter, and one on exhaust pipe behind catalytic converter. Heated oxygen sensor on exhaust pipe in front of catalytic converter may be referred to as bank No. 1 sensor No. 1. Heated oxygen sensor exhaust pipe behind catalytic converter may be referred to as bank No. 1 sensor No. 2.
2. To test the heater on the heated oxygen sensor, disconnect electrical connector from appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 92)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 92) Replace heated oxygen sensor if resistance is not within specification. See «OXYGEN SENSOR HEATER RESISTANCE»(ref-95583-S22431172102001040200000) table.
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

OXYGEN SENSOR HEATER RESISTANCE

Scheme 92

Avalon, Camry, Sienna, Tacoma, T100 & 4Runner

1. Knock sensors No. 1 and 2 are located below intake manifold on the cylinder block. (Scheme 93)-27. Manufacturer recommends removing knock sensor from cylinder block before testing. See appropriate REMOVE/INSTALL/OVERHAUL article.
2. Using ohmmeter, check that no continuity exists between electrical terminal on knock sensor and body of knock sensor. Replace knock sensor if continuity exists.

1. Knock sensors No. 1 and 2 are located below intake manifold on the cylinder block. (Scheme 93)-27. Remove intake manifolds for access to knock sensor. See appropriate REMOVE/INSTALL/OVERHAUL article.
2. Using ohmmeter, check that no continuity exists between electrical terminal on knock sensor and body of knock sensor. Replace knock sensor if continuity exists.

Scheme 93

Scheme 94

Scheme 95

All A/T Models

1. Disconnect electrical connector from Park/Neutral Position (PNP) switch. PNP switch is mounted on side of transmission/transaxle. Note terminal identification. (Scheme 96)
2. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(ref-95583-S11082986252001040200000) table. If proper continuity cannot obtained, adjust or replace switch as necessary.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 96

Power steering pressure switch is located on power steering pump, near the pressure hose. Testing information is not available.

For testing of throttle control motor, see THROTTLE BODY under IDLE CONTROL SYSTEM.

1. Ensure ignition is off. Disconnect electrical connector from Throttle Position (TP) sensor mounted on side of throttle body. Note terminal identification on TP sensor. (Scheme 97)-32.
2. Apply vacuum to throttle opener. Using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-95583-S06611560392001040200000) table. Replace components as necessary if resistance is not within specification.

For testing of throttle position sensor, see THROTTLE BODY under IDLE CONTROL SYSTEM.

Scheme 97

Scheme 98

Scheme 99

Scheme 100

THROTTLE POSITION SENSOR RESISTANCE (1)

VAPOR PRESSURE SENSOR

For testing of vapor pressure sensor, see FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS .

1. Vehicle speed sensor is located on transaxle. (Scheme 101)-34. Remove vehicle speed sensor. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 103)-36.
2. Using jumper wires, connect positive battery terminal to terminal No. 1 (outer terminal) and negative battery terminal to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 103)-36.
3. While rotating vehicle speed sensor shaft, ensure voltage changes from zero to at least 11 volts. Voltage should change 4 times per revolution of the shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

Vehicle speed sensor is located on transmission. (Scheme 101)-34. Testing information is not available.

Sienna, Tacoma & 4Runner

1. Wheel speed sensors on each wheel deliver an input signal to Anti-Lock Brake System (ABS) Electronic Control Unit (ECU). ABS ECU converts input signals from wheel speed sensors to a 4-pulse input signal to the instrument cluster. Instrument cluster then converts 4-pulse input signal to a rectangular waveform and then sends input signal to Engine Control Module (ECM).
2. If problem exists with vehicle speed sensor, a Diagnostic Trouble Code (DTC) will be stored in Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

T100

1. Vehicle speed sensor is located on rear of combination meter in instrument cluster. Connect ohmmeter between terminals "A" and "B" on rear of combination meter. Terminals are located near vehicle speed sensor. (Scheme 105)
2. Rotate speedometer cable shaft and note reading. Ohmmeter should deflect from continuity to no continuity 4 times per revolution of speedometer cable shaft. Replace speedometer if reading does not deflect as specified.

Scheme 101

Scheme 102

Scheme 103

Scheme 104

Scheme 105

1. The 4WD switch is located on side of transfer case and contains a Gray 2-pin electrical connector. Remove 4WD switch from transfer case. Connect ohmmeter between electrical terminals on 4WD switch.
2. Push pin on end of 4WD switch inward and ensure continuity exists. No continuity should exist when pin is released (outward) position. Replace 4WD switch if defective.

See FUEL DELIVERY under FUEL SYSTEM.

For testing of throttle control motor, see THROTTLE BODY under IDLE CONTROL SYSTEM.

CIRCUIT OPENING RELAY

Note. Circuit opening relay is used on all models except Land Cruiser.

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(ref-95583-S34029405662001040200000) table. (Scheme 106)-43. CIRCUIT OPENING RELAY LOCATION Application Location Avalon (1) Top Rear Corner Of Relay Box Behind Passenger's Side Kick Panel Camry & Sienna (1) In Relay Box At Driver's Side Front Corner Of Engine Bay, Near Battery & Air Cleaner Tacoma Behind Lower Instrument Panel Cover, Next To Driver's Side Of Steering Column T100 Behind Glove Box, Near Passenger's Side Kick Panel 4Runner Below Right Corner Of Fuse/Relay Box Behind Lower Instrument Panel Cover At Driver's Side Of Instrument Panel To Left Of Steering Column, Just Above Hood Release Lever (1) Circuit opening relay may be marked as CIR OPN relay in the relay box.
2. To test circuit opening relay continuity, use ohmmeter to check continuity between specified terminals. (Scheme 112)-49.
3. To test circuit opening relay operation, apply battery voltage and ground to relay and use ohmmeter to check continuity between specified terminals. (Scheme 112)-49. Replace circuit opening relay if defective.

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

Scheme 111

EFI MAIN RELAY

Note. EFI main relay may also be referred to as EFI relay.

1. Ensure ignition is off. Remove EFI main relay from relay box at driver's side front corner of engine compartment, near battery.
2. To test EFI main relay continuity, use ohmmeter to check continuity between specified terminals. (Scheme 112)-51.
3. To test EFI main relay operation, apply battery voltage and ground to relay and use ohmmeter to check continuity between specified terminals. (Scheme 112)-51. Replace EFI main relay if defective.

Scheme 112

Scheme 113

Scheme 114

Scheme 115

Scheme 116

Scheme 117

Scheme 118

See CIRCUIT OPENING RELAY under MOTORS & RELAYS.

EFI Main Relay (Fuel Pump Relay)

See EFI MAIN RELAY under MOTORS & RELAYS.

Fuel Pump Electronic Control Unit (Land Cruiser & LX470)

Fuel pump Electronic Control Unit (ECU) is located behind inner panel, just behind driver's rear wheelwell. (Scheme 119) Testing information is not available. If problem exists with fuel pump ECU or wiring circuit, a Diagnostic Trouble Code (DTC) P1200 will be stored in Engine Control Module (ECM). For diagnosis of DTC, see appropriate TESTS W/CODES article.

Scheme 119

Note. Fuel pump switch may also be referred to as fuel pump inertia switch or fuel pump control switch.

Fuel Pump Switch (Land Cruiser & LX470)

1. Fuel pump switch is located on driver's side of instrument panel and contains a reset switch. (Scheme 120) Disconnect electrical connector at fuel pump switch. It may be necessary to remove carpet and fuel pump switch for access to electrical connector.
2. Using ohmmeter, check that no continuity exists between electrical terminals on fuel pump switch with reset switch in OFF position. Check that continuity exists between electrical terminals on fuel pump switch with reset switch in ON position. Replace fuel pump switch if defective. Ensure reset switch is in the ON position for fuel pump operation.

Scheme 120

Fuel Pump Pressure

For fuel pump pressure testing, see appropriate BASIC TESTING article.

Fuel Injectors (Sienna)

1. Remove "V" bank cover on top of engine for access to fuel injectors. (Scheme 71)-4. Ensure ignition is off.
2. Disconnect electrical connector at fuel injector. Using ohmmeter, check resistance between electric terminals on fuel injector. Replace fuel injector if resistance is not 13.4-14.2 ohms at 68°F (20°C).
3. To check fuel injector volume, remove fuel injector. See appropriate REMOVE/INSTALL/OVERHAUL article. Fuel injector is connected to fuel filter for checking fuel injector volume.
4. Ensure area around fuel hose and outlet on top of fuel filter is clean. Remove union bolts with gaskets, and disconnect fuel hose from outlet at top of fuel filter. Install Union (SST 90405-09015) and delivery hose from Fuel Injector Measuring Kit (SST 09268-41047), gaskets and union bolt on top of fuel filter. see scheme 61-64. Tighten union bolt to 22 ft. lbs. (30 N.m).
5. Check that grommet and "O" ring are installed on top of fuel injector. Using Clamp (SST 09268-41100), and adapter from fuel injector measuring kit, connect fuel injector to the delivery hose. see scheme 61-64.
6. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage.
7. Connect scan tool to data link connector No. 3. see scheme 65-71. Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: Fuel pump may also be operated to pressurize fuel system by applying battery voltage to electrical terminals on fuel pump. For operating of fuel pump, see FUEL PUMP RESISTANCE & OPERATION under «FUEL DELIVERY»(ref-95583-S11888205302001040200000) under FUEL SYSTEM.
8. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. see scheme 72 Measure fuel injector volume. Test each fuel injector 2-3 times. Replace fuel injector if fuel injector volume is not within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-95583-S13733065552001040200000) table. NOTE: Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME»(ref-95583-S13733065552001040200000) SPECIFICATIONS table.
9. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop within 12 minutes. Replace fuel injector if leakage exceeds specification. Disconnect negative battery cable. Remove test equipment.
10. Using NEW gaskets, install fuel hose on top of fuel filter. Tighten union bolt to 22 ft. lbs. (30 N.m). Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

Fuel Injectors (Tacoma, T100 & 4Runner)

1. Remove necessary components for access to fuel injectors. Ensure ignition is off. Disconnect electrical connector at fuel injector.
2. Using ohmmeter, check resistance between electric terminals on fuel injector. Replace fuel injector if resistance is not 13.8 ohms at 68°F (20°C).
3. To check fuel injector volume, remove fuel injector. See appropriate REMOVE/INSTALL/OVERHAUL article. Fuel injector is connected to fuel inlet pipe and fuel pressure regulator for checking fuel injector volume.
4. Ensure area around fuel inlet pipe and fuel inlet hose is clean. Fuel inlet hose goes from the fuel inlet pipe near the frame up to the fuel rail. Disconnect fuel inlet hose from fuel inlet pipe. Connect Adapter (SST 09268-52011) and delivery hose from Fuel Injector Measuring Kit (SST 09268-41046) to fuel inlet pipe. see scheme 61-64.
5. Remove fuel pressure regulator from fuel rail. See appropriate REMOVE/INSTALL/OVERHAUL article. Using NEW "O" ring, install Union (SST 09268-41091) on fuel pressure regulator. see scheme 61-64. Connect delivery hose to union and fuel return hose on fuel pressure regulator.
6. Check that "O" ring is installed on top of fuel injector. Using clamp and union from fuel injector measuring kit, connect fuel injector to the delivery hose. see scheme 61-64.
7. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage.
8. Connect scan tool to data link connector No. 3. see scheme 65-71. Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: Fuel pump may also be operated to pressurize fuel system by applying battery voltage to electrical terminals on fuel pump. For operating of fuel pump, see FUEL PUMP RESISTANCE & OPERATION under «FUEL DELIVERY»(ref-95583-S11888205302001040200000) under FUEL SYSTEM.
9. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. see scheme 72 Measure fuel injector volume. Test each fuel injector 2-3 times. Replace fuel injector if fuel injector volume is not within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-95583-S13733065552001040200000) table. NOTE: Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME»(ref-95583-S13733065552001040200000) SPECIFICATIONS table.
10. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop within one minute. Replace fuel injector if leakage exceeds specification. Disconnect negative battery cable. Remove test equipment.
11. Using NEW "O" ring, install fuel pressure regulator. Tighten bolts to 71 INCH lbs. (8.0 N.m). Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

FUEL INJECTOR VOLUME SPECIFICATIONS

Fuel Cut System

1. On Avalon, Camry and Sienna, remove "V" bank cover on top of engine for access to fuel injectors. (Scheme 71)-4.
2. On all models, connect scan tool to data link connector No. 3. see scheme 65-71. Scan tool is used to read engine RPM. Start engine and warm engine to normal operating temperature.
3. Ensure A/C and all accessories are off. Gradually increase engine RPM to specified RPM. See «FUEL CUT SYSTEM TESTING SPEED»(ref-95583-S35823342272001040200000) table. FUEL CUT SYSTEM TESTING SPEED Application Engine RPM Avalon, Camry, Sienna, Tacoma, T100 & 4Runner 3500 Land Cruiser & LX470 2500
4. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily and then resumes operating (fuel return RPM).
5. Ensure fuel return RPM is within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(ref-95583-S39434712732001040200000) table. Shut engine off. Remove scan tool.

FUEL CUT SYSTEM SPECIFICATIONS (1)

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in appropriate ON-VEHICLE ADJUSTMENTS article.
2. Turn ignition off. Apply parking brake and place transmission/transaxle in Neutral. Ensure A/C is off. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1 located in the engine compartment. (Scheme 121)-76. See «DATA LINK CONNECTOR NO»(ref-95583-S36486426722001040200000). 1 LOCATION table. DATA LINK CONNECTOR NO. 1 LOCATION Application Location Avalon & Camry On End Of Air Intake Chamber At Passenger's Side Of Engine Sienna On Engine Mount Bracket Near Passenger's Side Strut Tower Tacoma, T100 & 4Runner Center Of Air Intake Chamber At Driver's Side Of Engine
3. Start engine and note engine RPM. After engine RPM is kept at 1000 RPM for 5 seconds, ensure engine returns to idle speed. If engine speed is not as specified, test IAC valve resistance and IAC valve operation. If engine speed is as specified, remove jumper wire. Turn ignition off.
4. To test IAC valve resistance, ensure ignition is off. Disconnect electrical connector from IAC valve. IAC valve is located on lower area of throttle body. Using ohmmeter, checking resistance between +B terminal and each remaining terminal on IAC valve. (Scheme 124)-79.
5. Replace IAC valve if resistance is not within specification. See «IAC VALVE RESISTANCE»(ref-95583-S27585917482001040200000) table. IAC VALVE RESISTANCE Application Ohms All Models Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C).
6. To test IAC valve operation, remove IAC valve from throttle body. See appropriate REMOVE/INSTALL/OVERHAUL article. Apply battery voltage to +B terminal on IAC valve. Apply battery ground to proper terminal and ensure valve opens and closes. (Scheme 127)-81. Replace IAC valve if defective.
7. If IAC valve resistance is within specification and operates correctly, check wiring circuit between Engine Control Module (ECM) and IAC valve. See «ECM LOCATION»(ref-95583-S13592534272001040200000) table. See appropriate wiring diagram in WIRING DIAGRAMS article.

Note. If all components and wiring circuit are okay, but idle problem still exists, the air assist system may be defective. For testing of air assist system, see AIR ASSIST SYSTEM under IDLE CONTROL SYSTEM .

ECM LOCATION

Scheme 121

Scheme 122

Scheme 123

Scheme 124

Scheme 125

Scheme 126

Scheme 127

Scheme 128

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in appropriate ADJUSTMENTS article.
2. Turn ignition off. Apply parking brake and place transmission/transaxle in Neutral. Ensure A/C is off. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1 located in the engine compartment. (Scheme 121)-76. See «DATA LINK CONNECTOR NO»(ref-95583-S36486426722001040200000). 1 LOCATION table. DATA LINK CONNECTOR NO. 1 LOCATION Application Location Avalon & Camry On End Of Air Intake Chamber At Passenger's Side Of Engine Sienna On Engine Mount Bracket Near Passenger's Side Strut Tower Tacoma, T100 & 4Runner Center Of Air Intake Chamber At Driver's Side Of Engine
3. Start engine and note engine RPM. After engine RPM is kept at 900-1300 RPM for 10 seconds, ensure engine returns to idle speed. Turn ignition off.
4. On Avalon, Camry and Sienna, disconnect air assist hose from air pipe. (Scheme 129)-84. Air assist hose fits between IAC valve and air pipe. Place plug on end of air pipe and air assist hose. (Scheme 129)-84.
5. On Tacoma, T100 and 4Runner, disconnect air assist hose from IAC valve. (Scheme 129)-84. Place plug on end of air assist hose. (Scheme 129)-84.
6. On all models, start engine and note idle speed. Idle speed should be 500 RPM or less which may cause the engine to stall. Turn ignition off.
7. If idle speed is not 500 RPM or less, check for air leak between air assist hoses, air pipe and fuel injectors. Remove plug(s) and jumper wire. Reconnect air assist hose.

Scheme 129

Scheme 130

Scheme 131

THROTTLE BODY

Note. Land Cruiser & LX470 uses Electronic Throttle Control System (ETCS) for controlling idle speed. ETCS consists of throttle body, accelerator pedal position sensor, Throttle Position (TP) sensor, throttle control motor, magnetic clutch and Engine Control Module (ECM).

Scheme 132

Scheme 133

Scheme 134

1. Remove intake manifold cover located on top of engine for access to throttle body. Ensure throttle cable and throttle lever on throttle body move smoothly. Note location of throttle control motor on throttle body. (Scheme 132)
2. Turn ignition on. Rotate throttle lever on throttle body to full throttle while listing for operating sound at throttle control motor and that no grinding noise is heard at throttle control motor and throttle body. Throttle lever will also rotate accelerator pedal position sensor.
3. If throttle control motor operating sound is heard, go to next step. If throttle control motor operating sound is not heard, throttle control motor, wiring harness or Engine Control Motor (ECM) may be defective. The ECM is located above glove box, near passenger's side of instrument panel. Go to step 12) for testing of throttle control motor.
4. To test operation of accelerator pedal position sensor, scan tool may be used or voltmeter may be used. If using scan tool, go to next step. If using voltmeter, go to step 8).
5. Connect scan tool to data link connector No. 3. see scheme 65-71. Scan tool is used to read throttle valve opening which is displayed as a percentage. Ensure Malfunction Indicator Light (MIL) on instrument panel is not illuminated. If MIL is not illuminated, go to next step. If MIL is illuminated, a Diagnostic Trouble Code (DTC) may be stored in the ECM. For diagnosis of DTC, see appropriate TESTS W/CODES article.
6. Rotate throttle lever on throttle body to full throttle while reading throttle valve opening on scan tool which is accessed by THROTTLE POS under CURRENT DATA. Throttle lever will also rotate accelerator pedal position sensor. Throttle valve opening should be at least 60 percent.
7. If throttle valve opening is at least 60 percent, go to step 10). If throttle valve opening is not at least 60 percent, problem may exist in accelerator pedal position sensor, wiring circuit or ECM. Go to step 15) for testing of accelerator pedal position sensor.
8. Access the ECM located above glove box, near passenger's side of instrument panel. Ensure ignition is turned on. Using voltmeter, check voltage between ECM terminals VPA (Red wire) and E2 (Brown/White wire) with accelerator pedal released and with accelerator pedal fully depressed. (Scheme 133)
9. Voltage should.3-.9 volt with accelerator pedal released and 3.2-4.8 volts with accelerator pedal fully depressed. If voltage is within specification, go to next step. If voltage is not within specification, problem may exist in accelerator pedal position sensor, wiring circuit or ECM. Go to step 15) for testing of accelerator pedal position sensor.
10. Start engine and allow engine to idle. Check operation of Malfunction Indicator Light (MIL) on instrument panel. If MIL is not illuminated, go to next step. If MIL is illuminated, a Diagnostic Trouble Code (DTC) may be stored in the ECM. For diagnosis of DTC, see appropriate TESTS W/CODES article.
11. To test operation of air assist system, allow engine to warm to normal operating temperature. Apply parking brake. Place transmission in Neutral. Ensure A/C is off. Note engine idle speed. Engine idle speed should be 650-750 RPM. If all steps above have been performed, drive vehicle to verify proper operation of throttle body.
12. To test throttle control motor, disconnect electrical connector at throttle control motor. (Scheme 132) Note terminal identification on throttle control motor. (Scheme 134)
13. Using ohmmeter, check resistance between specified terminals. See «THROTTLE CONTROL MOTOR RESISTANCE»(ref-95583-S10299427892001040200000) table. If resistance is within specification, reinstall electrical connector. If resistance is not within specification, replace throttle control motor. See appropriate REMOVE/INSTALL/OVERHAUL article. THROTTLE CONTROL MOTOR RESISTANCE Terminal No. Ohms @ 68°F (20°C) 1 (M+) Red Wire & 2 (M-) White Wire.3-100.0 3 (CL-) Blue Wire & 4 (CL+) Green Wire 4.2-5.2
14. To test TP sensor, disconnect electrical connector at TP sensor. (Scheme 132) Using ohmmeter, check resistance between terminals VC (Blue/Red wire) and E2 (Brown/White wire) on TP sensor. (Scheme 135) Replace TP sensor if resistance is not 1.25-2.35 ohms at 68°F (20°C). See appropriate REMOVE/INSTALL/OVERHAUL article.
15. To test accelerator pedal position sensor, disconnect electrical connector at accelerator pedal position sensor. (Scheme 132) Using ohmmeter, check resistance between terminals VC (Blue/Red wire) and E2 (Brown/White wire) on accelerator pedal position sensor. (Scheme 136) Replace accelerator pedal position sensor if resistance is not 1.64-3.28 ohms at 68°F (20°C). See appropriate REMOVE/INSTALL/OVERHAUL article.

Scheme 135

Scheme 136

IGNITION SYSTEM

Note. For basic ignition checks, see appropriate BASIC TESTING article.

Knock Sensor

See KNOCK SENSOR under ENGINE SENSORS & SWITCHES.

Manufacturer does not list an EGR system test, only individual component testing is listed. If a problem exists in the EGR system, a Diagnostic Trouble Code (DTC) P0401 or P0402 may be stored in the Engine Control Module (ECM). For DTC diagnosis, see appropriate TESTS W/CODES article.

Tacoma 2WD Models & 4WD W/Regular Cab & T100 2WD 1/2 Ton

1. Remove cap and filter from top of EGR vacuum modulator. Ensure filter is clean and in good condition. Clean filter with compressed air (if necessary). NOTE: Filter must be installed in EGR vacuum modulator with coarse side facing upward, away from EGR vacuum modulator.
2. Reinstall filter and cap. Using 3-way connector, install vacuum gauge in vacuum hose on top of EGR valve. This is the vacuum hose that goes from top of EGR valve to EGR Vacuum Switching Valve (VSV). Start engine. Ensure engine runs and idles smoothly to ensure proper seating of EGR valve.
3. To test operation of EGR VSV with engine cold, ensure engine coolant temperature is less than 113°F (45°C). Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1 at center of the air intake chamber at driver's side of engine. (Scheme 121)-76.
4. Increase and maintain engine speed at 2800 RPM. Ensure no vacuum reading is obtained on vacuum gauge with engine at 2800 RPM. EGR pipe should not be hot.
5. To test operation of EGR VSV with engine warm, operate engine until engine coolant temperature is greater than 176°F (80°C). Operate engine at 2800 RPM again. Ensure low vacuum reading is now obtained.
6. Disconnect vacuum hose from port "R" on EGR vacuum modulator. (Scheme 137) Using additional hose, connect port "R" on EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained with engine at 3500 RPM. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
7. Shut engine off. Remove vacuum hose, vacuum gauge and reconnect original vacuum hoses. Remove jumper wire from data link connector No. 1.
8. To test EGR valve operation, remove and plug vacuum hose located on top of EGR valve. Start engine. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall if EGR valve is operating properly. If EGR system does not operate as described, each individual component should be tested. Shut engine off.

Scheme 137

Scheme 138

Scheme 139

Scheme 140

Scheme 141

Scheme 142

Scheme 143

Avalon, Camry, Tacoma 2WD All Models & 4WD Regular Cab, & T100 2WD 1/2 Ton

See EGR GAS TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES .

EGR POSITION SENSOR

Note. EGR position sensor may also be referred to as EGR valve position sensor.

1. Disconnect electrical connector from EGR position sensor. EGR position sensor is located on top of EGR valve. (Scheme 144)
2. Using ohmmeter, check resistance between terminals E2 and VC on EGR position sensor. (Scheme 144) Resistance should be 1500-4300 ohms. If resistance is within specification, reinstall electrical connector on EGR position sensor and go to next step. If resistance is not within specification, replace EGR position sensor.
3. To test EGR position sensor output voltage, disconnect vacuum hose from EGR valve. Remove glove box for access to Engine Control Module (ECM).
4. Turn ignition on. Using voltmeter, check voltage between ECM terminals E2 and VC. (Scheme 145) See «ECM TERMINAL APPLICATION»(ref-95583-S33273692572001040200000) table for E2 and VC terminal wire colors. Voltage should be 4.5-5.5 volts. Remove voltmeter.
5. Connect voltmeter between ECM terminals E2 and EGLS. (Scheme 146) See «ECM TERMINAL APPLICATION»(ref-95583-S33273692572001040200000) table for E2 and EGLS terminal wi re colors. 6) Using vacuum pump, apply 5.1 in. Hg of vacuum to EGR valve and note voltage. Voltage should be 3.2-5.1 volts with vacuum applied on EGR valve. Release vacuum from EGR valve and note voltage. Voltage should be.4-1.6 volts with vacuum released from EGR valve. Replace EGR position sensor if voltage is not within specification. Remove vacuum pump and reinstall vacuum hose on EGR valve.

ECM TERMINAL APPLICATION

Scheme 144

Scheme 145

Scheme 146

EGR VACUUM CONTROL VALVE

Note. EGR vacuum control valve may also be referred to as the EGR VCV.

1. Disconnect vacuum hoses and remove EGR vacuum control valve. EGR vacuum control valve is located on top of engine, near EGR valve. (Scheme 138)-96.
2. Plug port "Z" and connect vacuum pump to port "S" on EGR vacuum control valve. (Scheme 147)
3. Using vacuum pump, apply 11.8 in. Hg of vacuum to EGR vacuum control valve. Vacuum pump should be operated 3 times so applied vacuum on EGR vacuum control valve remains at 8.6-11.8 in. Hg of vacuum.
4. Stop operating the vacuum pump after 3 times and note vacuum reading. Vacuum reading should decrease to 4.4-7.1 in. Hg of vacuum after 10 seconds. Replace EGR vacuum control valve is vacuum reading is not within specification.

Scheme 147

EGR VACUUM MODULATOR

Note. When testing EGR vacuum modulator, it may be necessary to monitor engine RPM by using scan tool. Scan tool may be connected to data link connector No. 3 for monitoring engine RPM. see scheme 65-71.

1. Mark vacuum hose locations and disconnect vacuum hoses from EGR vacuum modulator. (Scheme 138)-96. Block ports "P" and "R" on EGR vacuum modulator. (Scheme 137) NOTE: Ports "P" and "R" are the double ports on side of EGR vacuum modulator. Port "Q" is single port on side of EGR vacuum modulator.
2. Apply air pressure to port "Q". (Scheme 137) Air should flow freely through air filter side of EGR vacuum modulator.
3. Start engine and operate engine at 3500 RPM. Repeat test procedures in steps 1) and 2). Strong resistance of airflow should be felt. Replace EGR vacuum modulator if strong resistance is not felt. Reconnect vacuum hoses to proper locations.

1. Remove "V" bank cover and emission control valve set located on top of engine for access to EGR VSV. (Scheme 71)-4.
2. Remove EGR VSV. Using ohmmeter, ensure continuity exists between electrical terminals on EGR VSV and resistance is 27-33 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists or resistance is not within specification.
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of EGR VSV. Replace EGR VSV if continuity exists between electrical terminal and body of EGR VSV.
4. To test EGR VSV operation, apply air pressure to port "E". Ensure air flows from port "G". Perform STEP 1. (Scheme 148)
5. Apply battery voltage and ground to electrical terminals on EGR VSV. Apply air pressure to port "E". Ensure air flows from port "F" and not from port "G". Perform STEP 2. (Scheme 148) Replace EGR VSV if defective. Reinstall EGR VSV.

Scheme 148

1. Remove EGR VSV. (Scheme 138)-96. Using ohmmeter, ensure continuity exists between electrical terminals on EGR VSV and resistance is 33-39 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists or resistance is not within specification.
2. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of EGR VSV. Replace EGR VSV if continuity exists between electrical terminal and body of EGR VSV.
3. To test EGR VSV operation, apply air pressure to port "E". Ensure air flows from port "G" and not from the filter. Perform STEP 1. (Scheme 149)
4. Apply battery voltage and ground to electrical terminals on EGR VSV. Apply air pressure to port "E". Ensure air flows from filter and not from port "G". Perform STEP 2. (Scheme 149) Replace EGR VSV if defective. Reinstall EGR VSV.

Scheme 149

Avalon, Camry, Tacoma 2WD Models & 4WD W/Regular Cab & T100 2WD 1/2 Ton

1. Remove EGR valve. See appropriate REMOVE/INSTALL/OVERHAUL article.
2. Inspect EGR valve for restricted passages caused by carbon deposits. Using vacuum pump, apply vacuum directly to EGR valve and ensure valve opens. Release vacuum and ensure valve closes. Replace EGR valve if defective.

FUEL EVAPORATION SYSTEM

Note. Fuel evaporation systems contain different components depending on application. (Scheme 138)-96.

Note. Charcoal canister may also be referred to as EVAP canister.

Charcoal Canister (Avalon, Camry & Sienna)

1. Remove charcoal canister. (Scheme 138)-96. Inspect charcoal canister for cracks or damage. Install plug on port "E" on charcoal canister. (Scheme 150)-107.
2. Check for clogged filter and/or stuck check valve and diaphragm by applying.26 psi (.018 kg/cm 2 ) air pressure to port "A" while holding port "B" closed. (Scheme 150)-107. Ensure air flows freely from port "D".
3. Apply.26 psi (.018 kg/cm 2 ) air pressure to port "A" while holding ports "B" and "D" closed. (Scheme 150)-107. Ensure no air flows from port "C".
4. Using vacuum pump, apply 1.01 in. Hg of vacuum to port "B". Ensure vacuum does not decrease when port "C" is closed, and that vacuum decreases with port "C" is opened.
5. While holding port "C" closed, use vacuum pump to apply 1.01 in. Hg of vacuum to port "A". Ensure air flows into port "B". Replace charcoal canister if defective.

Charcoal Canister (Land Cruiser & LX470)

1. Remove charcoal canister. (Scheme 138)-96. Inspect charcoal canister for cracks or damage. Check for clogged filter and/or stuck check valve and diaphragm by applying.26 psi (.018 kg/cm 2 ) air pressure to port "A" while holding port "B" closed. (Scheme 150)-107. Ensure air flows freely from port "D".
2. Apply.26 psi (.018 kg/cm 2 ) air pressure to port "A" while holding ports "B" and "D" closed. (Scheme 150)-107. Ensure no air flows from port "C".
3. Using vacuum pump, apply 1.01 in. Hg of vacuum to port "B". Ensure vacuum does not decrease when port "C" is closed, and that vacuum decreases with port "C" is opened.
4. While holding port "C" closed, use vacuum pump to apply.39 in. Hg of vacuum to port "A". Ensure air flows into port "B". Replace charcoal canister if defective.

Charcoal Canister (Tacoma & 4Runner)

1. Remove charcoal canister. (Scheme 138)-96. Inspect charcoal canister for cracks or damage. Remove Vacuum Switching Valves (VSV) from top of charcoal canister.
2. Install plugs on ports "A" and "B". (Scheme 150)-107. Check for clogged filter and/or stuck check valve or diaphragm by applying.21 psi (.015 kg/cm 2 ) air pressure to port "D" while holding port "C" closed. (Scheme 150)-107. Ensure air flows freely from port "E".
3. Apply.21 psi (.015 kg/cm 2 ) air pressure to port "D" while holding ports "C" and "E" closed. (Scheme 150)-107. Ensure no air flows from port "F".
4. Using vacuum pump, apply.87 in. Hg of vacuum to port "C". Ensure vacuum does not decrease when port "F" is closed, and that vacuum decreases with port "F" is opened.
5. While holding port "F" closed, use vacuum pump to apply.87 in. Hg of vacuum to port "D". Ensure vacuum does not decrease when port "C" is closed, and that vacuum decreases with port "C" is opened. Remove plugs. Replace charcoal canister if defective.

Charcoal Canister (T100)

1. Remove charcoal canister. (Scheme 138)-96. Inspect charcoal canister for cracks or damage. Install plug on port "E" on charcoal canister. (Scheme 150)-107.
2. Check for clogged filter and/or stuck check valve and diaphragm by applying.21 psi (.015 kg/cm 2 ) air pressure to port "A" while holding port "B" closed. (Scheme 150)-107. Ensure air flows freely from port "D".
3. Apply.26 psi (.018 kg/cm 2 ) air pressure to port "A" while holding ports "B" and "D" closed. (Scheme 150)-107. Ensure no air flows from port "C".
4. Using vacuum pump, apply one in. Hg of vacuum to port "B". Ensure vacuum does not decrease when port "C" is closed, and that vacuum decreases with port "C" is opened.
5. While holding port "C" closed, use vacuum pump to apply.36 in. Hg of vacuum to port "A". Ensure air flows into port "B". Replace charcoal canister if defective.

Scheme 150

Scheme 151

Scheme 152

Scheme 153

Scheme 154

EVAP Vacuum Switching Valve

1. Remove EVAP Vacuum Switching Valve (VSV). See «EVAP VSV LOCATIONS»(ref-95583-S04297551362001040200000) table. (Scheme 71)-4 and 91-96. EVAP VSV LOCATIONS Application Location Avalon Front VSV On Emission Control Valve Set On Top Of Engine, Near Intake Manifold & Contains Blue 2-Pin Electrical Connector With Light Green & Black/Red Wires Camry & Sienna Front VSV On Emission Control Valve Set On Top Of Engine, Near Intake Manifold & Contains Blue 2-Pin Electrical Connector With Light Green & Black/Yellow Wires Land Cruiser & LX470 Mounted On Driver's Side Center Of Intake Manifold Below Intake Manifold Cover On Top Of Engine & Contains Black 2-Pin Electrical Connector With Blue/Black & Black/Yellow Wires Tacoma On End Of Charcoal Canister & Contains Black 2-Pin Electrical Connector With White/Red & White/Green Wires T100 On Top Of Charcoal Canister & Contains Black 2-Pin Electrical Connector With White/Red & White/Green Wires 4Runner On End Of Charcoal Canister & Contains Black 2-Pin Electrical Connector With White/Blue & White/Green Wires
2. Using ohmmeter, ensure continuity exists between electrical terminals on EVAP VSV and resistance is within specification. See «EVAP VSV RESISTANCE»(ref-95583-S18314398572001040200000) table. Replace EVAP VSV if no continuity exists or resistance is not within specification. EVAP VSV RESISTANCE Application Ohms @ 68°F (20°C) Avalon, Camry & Sienna 27-33 Land Cruiser, LX470 & Tacoma 30-34 T100 29-33 4Runner 30-34
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of EVAP VSV. Replace EVAP VSV if continuity exists between electrical terminal and body of EVAP VSV.
4. To test EVAP VSV operation, apply air pressure to port "E". Ensure no air flows from port "F". Perform STEP 1. (Scheme 155)or (Scheme 156).
5. Apply battery voltage and ground to electrical terminals on EVAP VSV. Apply air pressure to port "E". Ensure air flows from port "F". Perform STEP 2. (Scheme 155)or (Scheme 156). Replace EVAP VSV if defective.

Scheme 155

Scheme 156

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, disconnect electrical connector from vapor pressure sensor. (Scheme 138)-96. See «VAPOR PRESSURE SENSOR LOCATION»(ref-95583-S16946941772001040200000) table. VAPOR PRESSURE SENSOR LOCATION Application Location Avalon On Firewall, Near Passenger's Side Of Brake Booster & Contains Black 3-Pin Electrical Connector With Brown, Pink & Blue/Red Wires Camry On Firewall, Near Passenger's Side Of Brake Booster & Contains Gray 3-Pin Electrical Connector With Brown, Blue/Red & Yellow Wires Land Cruiser & LX470 On Rear Corner Of Charcoal Canister & Contains Black 3-Pin Electrical Connector With Brown/White, Blue/Red & Blue/Black Wires Sienna On Firewall, Near Brake Master Cylinder & Contains Black 3-Pin Electrical Connector With Brown, Blue/Red & Yellow Wires Tacoma On Firewall, Above Brake Booster & Contains Black 3-Pin Electrical Connector With Brown/Black, Green/Black & Red/Yellow Wires T100 On Firewall, Above Brake Booster & Contains Black 3-Pin Electrical Connector With Brown/Black, Green/Black & Red/Blue Wires 4Runner On Firewall, Above Brake Booster & Contains Black 3-Pin Electrical Connector With Brown/Black, Green/Black & Yellow/Black Wires
2. Turn ignition on. Using voltmeter, measure voltage between terminals VC and E2 on wiring harness side of electrical connector for vapor pressure sensor. The VC and E2 terminals are the 2 outer terminals. DO NOT use center terminal. Supply voltage should be 4.5-5.5 volts.
3. If supply voltage is not within specification, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor.
4. To test vapor pressure sensor output voltage, turn ignition on. Disconnect vacuum hose from vapor pressure sensor. Obtain access to Engine Control Module (ECM). See «ECM LOCATION»(ref-95583-S13592534272001040200000) table.
5. Connect voltmeter between specified ECM terminals. (Scheme 157)- and 111-112. See «ECM TERMINAL APPLICATION»(ref-95583-S33273692572001040200000) table. ECM LOCATION Model Location Avalon & Camry Behind Glove Box Land Cruiser & LX470 Above Glove Box, Near Passenger's Side Of Instrument Panel Sienna Passenger's Side Of Instrument Panel, Just Below Glove Box Tacoma Behind Glove Box T100 Behind Passenger's Side Kick Panel 4Runner Behind Glove Box ECM TERMINAL APPLICATION Application & Terminal Wire Color Avalon E2 Brown PTNK Pink Camry E2 Brown PTNK Blue/Red Land Cruiser & LX470 E2 Brown/White PTNK Blue/Black Sienna E2 Brown PTNK Blue/Red Tacoma E2 Brown/Black PTNK Red/Yellow T100 E2 Brown/Black PTNK Red/Blue 4Runner E2 Brown/Black PTNK Yellow/Black
6. Using vacuum pump, apply.59 in. Hg of vacuum to vapor pressure sensor. Ensure output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-95583-S07924900902001040200000) table.
7. Release vacuum from vapor pressure sensor. Ensure output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-95583-S07924900902001040200000) table.
8. Apply.22 psi (.015 kg/cm 2 ) to vapor pressure sensor. Ensure output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-95583-S07924900902001040200000) table. Replace vapor sensor if output voltage is not within specification. Reconnect vacuum hose.

VAPOR SENSOR OUTPUT VOLTAGE

Scheme 157

Scheme 158

Scheme 159

Vapor Pressure Sensor Vacuum Switching Valve

1. Remove vapor pressure sensor Vacuum Switching Valve (VSV). Vapor pressure sensor VSV is located on charcoal canister. (Scheme 138)-96.
2. Using ohmmeter, ensure continuity exists between electrical terminals on vapor pressure sensor VSV and resistance is within specification. See «VAPOR PRESSURE SENSOR VSV RESISTANCE»(ref-95583-S10558704292001040200000) table. Replace vapor pressure sensor VSV if no continuity exists or resistance is not within specification. VAPOR PRESSURE SENSOR VSV RESISTANCE Application Ohms @ 68°F (20°C) Avalon & Camry 33-39 Land Cruiser, LX470, Sienna, Tacoma, T100 & 4Runner 37-44
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of vapor pressure sensor VSV. Replace vapor pressure sensor VSV if continuity exists between electrical terminal and body of vapor pressure sensor VSV.
4. To test vapor pressure sensor VSV operation, apply air pressure to port "E". Ensure air flows from port "G" and not from port "F". Perform STEP 1. (Scheme 160)-115.
5. Apply battery voltage and ground to electrical terminals on vapor pressure sensor VSV. Apply air pressure to port "E". Ensure air flows from port "F" and not from port "G". Perform STEP 2. (Scheme 160)-115. Replace vapor pressure sensor VSV if defective.

Scheme 160

Scheme 161

Scheme 162

Avalon, Camry, Land Cruiser, LX470 & Sienna

1. Remove PCV valve. Apply air pressure to PCV valve at cylinder head side of PCV valve. Ensure air flows easily through PCV valve.
2. Apply air pressure to PCV valve at intake manifold side of PCV valve. Ensure air flows through PCV valve with some resistance. Replace PCV valve if valve does not function as described.

1. Remove PCV valve. Apply air pressure to PCV valve at cylinder head side of PCV valve. Ensure air flows easily through PCV valve.
2. Apply air pressure to PCV valve at intake manifold side of PCV valve. Ensure air flows through PCV valve with some resistance.
3. Apply air pressure to PCV valve at intake manifold side of PCV valve while using small screwdriver to push upward on valve located inside PCV valve, at cylinder head side of PCV valve. Ensure air flows through PCV valve with strong resistance. Replace PCV valve if valve does not function as described.

Tacoma With M/T, T100 With M/T & 4Runner With M/T

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in appropriate ADJUSTMENTS article. Shut engine off. Remove cap, filter and separator from dashpot on throttle body. (Scheme 163)
2. Start engine. Maintain engine speed at 2500 RPM. Plug Vacuum Transmitting Valve (VTV) hole in dashpot with your finger. (Scheme 164)
3. Release throttle. Dashpot should be extended and dashpot setting RPM should be 1800-2200 RPM. If dashpot setting RPM is not within specification, rotate dashpot adjusting screw to obtain correct RPM. (Scheme 165)
4. Remove finger from VTV hole in dashpot. Ensure engine returns to proper idle speed in approximately one second. Install separator, filter and cap. Ensure filter is installed with the coarse surface facing outward (away from dashpot).

Scheme 163

Scheme 164

Scheme 165

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in appropriate ADJUSTMENTS article.
2. Shut engine off. Disconnect and plug vacuum hose at throttle opener near throttle body. (Scheme 166)-122. Start engine and note engine speed. Engine speed should be 900-1950 RPM.
3. If engine speed is not within specification, replace throttle body. Shut engine off. Reinstall vacuum hose on throttle opener. Start engine and ensure engine returns to proper idle speed.

Scheme 166

Scheme 167

Scheme 168

Scheme 169