Engine Controls - System & Component Testing - V6 & V8: Other Toyota 4Runner III

ELECTRONIC THROTTLE CONTROL SYSTEM (ETCS)

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

Land Cruiser

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 240

Scheme 241

1. Using 3-way connector, connect vacuum gauge in vacuum line to actuator valve. (Scheme 240) 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 7.9 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 7.9 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 241) Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2. (Scheme 241)
5. Plug port "B" on vacuum tank. Using vacuum pump, apply 7.9 in. Hg of vacuum to port "A". Perform STEP 3. (Scheme 241) 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 242)and (Scheme 243). Disconnect electrical connector and vacuum hoses from intake air control valve Vacuum Switching Valve (VSV). (Scheme 242)and (Scheme 243). 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 244) 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 244) 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). For illustration of ECM location, see THEORY & OPERATION article. Turn ignition on. Using voltmeter, check voltage at ECM terminal ACIS (Red/Yellow wire). (Scheme 245) This is the wire from intake air control valve VSV to ECM. For additional identification of ECM terminals, see PIN VOLTAGE CHARTS 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-91239-S13562323952001030600000) under MOTORS & RELAYS. See appropriate wiring diagram in WIRING DIAGRAMS article.

Scheme 242

Scheme 243

Scheme 244

Scheme 245

Power & Ground Circuits

For testing of Engine Control Module (ECM) power and ground circuits, see PIN VOLTAGE CHARTS 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.

Scheme 246

1. Disconnect electrical connector for A/C compressor lock sensor. A/C compressor lock sensor is located near front of A/C compressor and electrical connector is located near generator. (Scheme 246) This is the electrical connector for A/C compressor lock sensor and magnetic clutch on front of A/C compressor.
2. Using ohmmeter, check resistance between terminals No. 1 and 2 on electrical connector for A/C compressor lock sensor. (Scheme 246) Replace A/C compressor assembly if resistance is not 65-125 ohms at 68°F (20°C).

AIR/FUEL (A/F) SENSOR

Note. Air/Fuel (A/F) sensor may also be referred to as Air/Fuel (A/F) ratio sensor.

Avalon Calif. Emission Vehicles, Camry Calif. Emission Vehicles With A/T, Camry Solara Calif. Emission Vehicles With A/T & Sienna Calif. Emission Vehicles

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 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 247) Replace A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C) and 1.8-3.2 ohms at 1472°F (800°C).
3. If problem exists in A/F sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 247

4Runner Calif. Emission Vehicles

1. Heated A/F is located on exhaust pipe in front of catalytic converter. Heated A/F sensor may be referred to as bank No. 1 sensor No. 1.
2. To check 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 248) Replace A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C) and 1.8-3.2 ohms at 1472°F (800°C).
3. If problem exists in A/F sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 248

AIRFLOW METER

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

Scheme 249

Scheme 250

1. Turn ignition off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter with gasket and note airflow meter terminal identification. (Scheme 249)
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-91239-S29791888242001030600000) 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 airflow meter with electrical connector installed. (Scheme 250)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 250) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter using NEW gasket.

Scheme 251

Scheme 252

1. Turn ignition off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to top side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter and note airflow meter terminal identification. (Scheme 251)
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-91239-S29791888242001030600000) 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 airflow meter with electrical connector installed. (Scheme 252)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 252) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter.

Scheme 253

Scheme 254

1. Turn ignition off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to air intake hose, near air cleaner assembly. Remove airflow meter with "O" ring (if equipped) and note airflow meter terminal identification. (Scheme 253)
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-91239-S29791888242001030600000) 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 airflow meter with electrical connector installed. (Scheme 254)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 254) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter using "O" ring (if equipped).

AIRFLOW METER RESISTANCE

Scheme 255

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on the brakelight switch. (Scheme 255)
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.

Scheme 256

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of the brake pedal. Note terminal identification on brakelight switch. (Scheme 256)
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.

CAMSHAFT POSITION SENSOR

For testing camshaft position sensor, see IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

CRANKSHAFT POSITION SENSOR

For testing crankshaft position sensor, see IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Avalon, Camry & Camry Solara

1. Manufacturer recommends removing throttle body for access to EGR gas temperature sensor. See THROTTLE BODY under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 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-91239-S05575463652001030600000) table. Replace EGR gas temperature sensor if resistance is not within specification. Reinstall EGR gas temperature sensor. EGR GAS TEMPERATURE SENSOR RESISTANCE Temperature °F (°C) Ohms 122 (50) 64,000-97,000 212 (100) 11,000-16,000 302 (150) 2000-4000

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

Avalon, Camry, Camry Solara & Sienna

1. Ensure ignition is off. Note location of ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-91239-S26185302562001030600000) table. Remove ECT sensor. See ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 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 257) 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-91239-S26185302562001030600000) table. Manufacturer recommends removing throttle body for access to ECT sensor. Remove ECT sensor. See ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 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 257) 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.

Tacoma & 4Runner

1. Note location of ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-91239-S26185302562001030600000) table. Manufacturer recommends removing upper timing belt cover and fuel crossover pipe for access to ECT sensor. Remove ECT sensor. See ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 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 257) 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 257

For testing of fuel pump switch, see FUEL PUMP SWITCH under FUEL DELIVERY under FUEL SYSTEM.

Scheme 258

Scheme 259

1. On Calif. emission vehicles, a heated oxygen sensor is used on exhaust pipe behind catalytic converter and Air/Fuel (A/F) sensor is used on each exhaust manifold. For testing of A/F sensor, see «AIR/FUEL (A/F) SENSOR»(ref-91239-S28500911142001030600000) under ENGINE SENSORS & SWITCHES. On except Calif. emission vehicles, heated oxygen sensor is used on each oxygen manifold and on exhaust pipe, behind catalytic converter.
2. 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.
3. To test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 258)and (Scheme 259). 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.
4. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 258)and (Scheme 259). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
5. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Camry & Camry Solara

1. On Calif. emission vehicles with A/T, a heated oxygen sensor is used on exhaust pipe behind catalytic converter and Air/Fuel (A/F) sensor is used on each exhaust manifold. For testing of A/F sensor, see «AIR/FUEL (A/F) SENSOR»(ref-91239-S28500911142001030600000) under ENGINE SENSORS & SWITCHES. On except Calif. emission vehicles with A/T, heated oxygen sensor is used on each exhaust manifold and on exhaust pipe, behind catalytic converter.
2. 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.
3. To test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 260)and (Scheme 261). 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.
4. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 260)and (Scheme 261). On Camry, replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C). On Camry Solara, replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
5. On all models, if problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 260

Scheme 261

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 heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 262)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 262) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. On all models, if problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 262

Sienna

1. On Calif. emission vehicles, a heated oxygen sensor is used on exhaust pipe behind catalytic converter and Air/Fuel (A/F) sensor is used on each exhaust manifold. For testing of A/F sensor, see «AIR/FUEL (A/F) SENSOR»(ref-91239-S28500911142001030600000) under ENGINE SENSORS & SWITCHES. On except Calif. emission vehicles, heated oxygen sensor is used on each exhaust manifold and on exhaust pipe, behind catalytic converter.
2. 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.
3. To test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 263)and (Scheme 264). 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.
4. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 263)and (Scheme 264). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
5. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 263

Scheme 264

1. On 4Runner Calif. emission vehicles, a heated oxygen sensor is used on exhaust pipe behind catalytic converter and Air/Fuel (A/F) sensor is used on exhaust pipe in front of catalytic converter. For testing of A/F sensor, see «AIR/FUEL (A/F) SENSOR»(ref-91239-S28500911142001030600000) under ENGINE SENSORS & SWITCHES. On 4Runner, except Calif. emission vehicles, heated oxygen sensor is used on exhaust pipe in front of catalytic converter, and one on exhaust pipe behind catalytic converter.
2. On all models, 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.
3. To test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 265)
4. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 265) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C).
5. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 265

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

1. Knock sensors No. 1 and 2 are located below intake manifold on cylinder block. (Scheme 266)and (Scheme 267). Manufacturer lists testing procedure with knock sensor removed from cylinder block before testing. Remove knock sensor. See ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 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 266

Scheme 267

1. Knock sensors No. 1 and 2 are located below intake manifold on cylinder block. (Scheme 268) Remove intake manifolds for access to knock sensor. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article for removal of intake manifolds.
2. Disconnect electrical connector at knock sensor. 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 268

A/T Models

1. Disconnect electrical connector at Park/Neutral Position (PNP) switch. PNP switch is mounted on side of transmission/transaxle. Note terminal identification. (Scheme 269)
2. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(ref-91239-S28640376592001030600000) table. If proper continuity cannot obtained, adjust or replace PNP switch as necessary.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 269

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

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

1. Ensure ignition is off. Disconnect electrical connector at Throttle Position (TP) sensor mounted on side of throttle body. Note terminal identification on TP sensor. (Scheme 270)- (Scheme 273).
2. Apply vacuum to throttle opener. Using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-91239-S00299047382001030600000) table. Replace components as necessary if resistance is not within specification.

THROTTLE POSITION SENSOR RESISTANCE (1)

Scheme 270

Scheme 271

Scheme 272

Scheme 273

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

VAPOR PRESSURE SENSOR

For testing of vapor pressure sensor, see VAPOR PRESSURE SENSOR under FUEL EVAPORATION SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS.

1. Vehicle speed sensor is located on transaxle. (Scheme 274) 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 275)and (Scheme 276).
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 275)and (Scheme 276).
3. While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts 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.

Scheme 274

Scheme 275

Scheme 276

Vehicle speed sensor is located on transmission. (Scheme 277) Testing information is not available from manufacturer.

Scheme 277

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). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 278

Scheme 279

Scheme 280

1. Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a 3-pin electrical connector. Electrical connector contains Blue, Green/Red and Pink wires.
2. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 278)- (Scheme 280).
3. 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 278)- (Scheme 280).
4. While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts 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.

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). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

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 PUMP ELECTRONIC CONTROL UNIT (LAND CRUISER) under FUEL DELIVERY under FUEL SYSTEM.

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

Scheme 281

1. A/F heater relay may also be referred to as A/F HTR relay. For A/F heater relay location, see «A/F HEATER RELAY LOCATION»(ref-91239-S36377931412001030600000) table. Testing information is not available from manufacturer. It may be necessary to consult wiring diagram for A/F heater relay testing. See appropriate wiring diagram in WIRING DIAGRAMS article. A/F HEATER RELAY LOCATION Application Location Avalon, Camry & Camry Solara In Small Fuse Relay Box At Driver's Side Front Corner Of Engine Compartment, In Front Of Battery Sienna (1) (1) Located near ECM behind passenger's side of instrument panel and contains a 4-pin connector. (Scheme 281)

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-91239-S24648648302001030600000) table. (Scheme 282)- (Scheme 286). CIRCUIT OPENING RELAY LOCATION (1) Application Location Avalon Top Corner Of Relay Box Behind Passenger's Side Kick Panel Camry, Camry Solara & Sienna In Relay Box At Driver's Side Front Corner Of Engine Compartment, Near Battery & Air Cleaner Tacoma Behind Lower Instrument Panel Cover, Next To Driver's Side Of Steering Column 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 for continuity and no continuity between specified terminals on circuit opening relay. (Scheme 287)- (Scheme 292).
3. To test circuit opening relay operation, apply battery voltage and ground to circuit opening relay and use ohmmeter to check continuity between specified terminals on circuit opening relay. (Scheme 287)- (Scheme 292). Replace circuit opening relay if defective.

Scheme 282

Scheme 283

Scheme 284

Scheme 285

Scheme 286

Scheme 287

Scheme 288

Scheme 289

Scheme 290

Scheme 291

Scheme 292

EFI MAIN RELAY

Note. EFI main relay is used on all models and 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 for continuity and no continuity between specified terminals on EFI main relay. (Scheme 287)- see scheme 55.
3. To test EFI main relay operation, apply battery voltage and ground to EFI relay and use ohmmeter to check continuity between specified terminals on EFI main relay. (Scheme 287)- see scheme 55. Replace EFI main relay if defective.

Scheme 293

See CIRCUIT OPENING RELAY under MOTORS & RELAYS.

See EFI MAIN RELAY under MOTORS & RELAYS.

Fuel Pump Electronic Control Unit (Land Cruiser)

Fuel pump Electronic Control Unit (ECU) is located behind inner panel, just behind driver's side rear wheelwell. (Scheme 294) Testing information is not available from manufacturer. If problem exists with fuel pump ECU or wiring circuit, a Diagnostic Trouble Code (DTC) P1200 will be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

Scheme 294

Fuel Pump Switch (Land Cruiser)

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

1. Fuel pump switch is located on driver's side of instrument panel and contains a reset switch. (Scheme 295) 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 295

Fuel Pump Pressure

For fuel pump pressure testing, see FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Fuel Cut System

1. On Avalon, Camry, Camry Solara and Sienna, remove "V" bank cover on top of engine for access to fuel injectors. (Scheme 242)and (Scheme 243).
2. On all models, connect scan tool to data link connector No. 3. see scheme 70- (Scheme 296). Scan tool is used to read engine RPM. Start engine and warm engine to normal operating temperature.
3. Ensure A/C is off. Gradually increase engine RPM to specified RPM. See «FUEL CUT SYSTEM TESTING SPEED»(ref-91239-S00989438822001030600000) table. FUEL CUT SYSTEM TESTING SPEED Application Engine RPM Avalon, Camry, Camry Solara, Sienna, Tacoma & 4Runner 3500 Land Cruiser 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-91239-S13397710732001030600000) 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 ON-VEHICLE ADJUSTMENTS - V6 & V8 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 297)- (Scheme 300). See «DATA LINK CONNECTOR NO. 1 LOCATION»(ref-91239-S42508584632001030600000) table. DATA LINK CONNECTOR NO. 1 LOCATION Application Location Avalon & Camry On End Of Air Intake Chamber At Passenger's Side Of Engine Camry Solara Passenger's Side Of Engine, Near Strut Tower Sienna On Engine Mount Bracket Near Passenger's Side Strut Tower Tacoma & 4Runner Center Of Air Intake Chamber At Driver's Side Of Engine
3. Start engine and note engine RPM. Engine should increase to 1000 RPM for 5 seconds and then return 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 at 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 301)- (Scheme 303).
5. Replace IAC valve if resistance is not within specification. See «IAC VALVE RESISTANCE»(ref-91239-S19346596712001030600000) table. IAC VALVE RESISTANCE Application Ohms Avalon Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 Camry Cold (1) 17.0-25.0 Hot (2) 21.5-29.5 Camry Solara & Sienna Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 Tacoma & 4Runner Cold (1) 17.0-25.0 Hot (2) 21.5-29.5 (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 IDLE CONTROL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. Apply battery voltage to +B terminal on IAC valve. Apply battery ground to proper terminal and ensure valve opens and closes. (Scheme 304)and (Scheme 305). 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-91239-S09635172122001030600000) 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»(ref-91239-S20626508342001030600000) under IDLE CONTROL SYSTEM.

ECM LOCATION

Scheme 296

Scheme 297

Scheme 298

Scheme 299

Scheme 300

Scheme 301

Scheme 302

Scheme 303

Scheme 304

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 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 297)- (Scheme 300). See «DATA LINK CONNECTOR NO. 1 LOCATION»(ref-91239-S15441019782001030600000) table. DATA LINK CONNECTOR NO. 1 LOCATION Application Location Avalon & Camry On End Of Air Intake Chamber At Passenger's Side Of Engine Camry Solara Passenger's Side Of Engine, Near Strut Tower Sienna On Engine Mount Bracket Near Passenger's Side Strut Tower Tacoma & 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, Camry Solara and Sienna, disconnect air assist hose from air pipe. (Scheme 306)and (Scheme 307). Air assist hose fits between IAC valve and air pipe. Place plug on end of air pipe and air assist hose. (Scheme 306)and (Scheme 307). Go to step 6.
5. On Tacoma and 4Runner, disconnect air assist hose from IAC valve. (Scheme 308) Place plug on end of air assist hose. (Scheme 308) Go to next step.
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 305

Scheme 306

Scheme 307

Note. Electronic Throttle Control System (ETCS) is used 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 308

Scheme 309

Scheme 310

Scheme 311

Scheme 312

1. On Land Cruiser, 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 309)
2. To check throttle control motor operation, 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. On Land Cruiser, ECM is located above glove box, near passenger's side of instrument panel. For illustration of ECM location, see THEORY & OPERATION article. 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 73 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 Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.
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 ECM located. On Land Cruiser, ECM is located above glove box, near passenger's side of instrument panel. For illustration of ECM location, see THEORY & OPERATION article. On all models, ensure ignition is turned on. Using voltmeter, check voltage between ECM terminals VPA and E2 with accelerator pedal released and with accelerator pedal fully depressed. (Scheme 310) See «ECM TERMINAL WIRE COLOR IDENTIFICATION»(ref-91239-S10358279822001030600000) table. ECM TERMINAL WIRE COLOR IDENTIFICATION Application & ECM Terminal Wire Color Land Cruiser E2 Brown/White VPA Red
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 Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.
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 previous steps 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 309) Note terminal identification on throttle control motor. (Scheme 311)
13. Using ohmmeter, check resistance between specified terminals on throttle control motor. See «THROTTLE CONTROL MOTOR RESISTANCE»(ref-91239-S00539992842001030600000) table. If resistance is within specification, reinstall electrical connector. Go to next step. If resistance is not within specification, replace throttle control motor. See THROTTLE BODY under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. THROTTLE CONTROL MOTOR RESISTANCE Terminal No. Ohms @ 68°F (20°C) 1 (M+) & 2 (M-).3-100.0 3 (CL-) & 4 (CL+) 4.2-5.2
14. To test TP sensor, disconnect electrical connector at TP sensor. (Scheme 309) Using ohmmeter, check resistance between terminals VC and E2 on TP sensor. (Scheme 312) Replace TP sensor if resistance is not 1250-2350 ohms at 68°F (20°C). See THROTTLE BODY under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
15. To test accelerator pedal position sensor, disconnect electrical connector at accelerator pedal position sensor. (Scheme 309) Using ohmmeter, check resistance between terminals VC and E2 on accelerator pedal position sensor. (Scheme 313) Replace accelerator pedal position sensor if resistance is not 1640-3280 ohms at 68°F (20°C). See THROTTLE BODY under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.

IGNITION SYSTEM

Note. For basic ignition checks, see IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Knock Sensors

See KNOCK SENSORS under ENGINE SENSORS & SWITCHES.

Scheme 313

Scheme 314

Scheme 315

Scheme 316

Manufacturer does not list an EGR system test, only individual component testing is listed. If a problem exists in EGR system, a Diagnostic Trouble Code (DTC) P0401, P0402 or P1410 may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.

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 at EGR position sensor. EGR position sensor is located on top of EGR valve. (Scheme 318)
2. Using ohmmeter, check resistance between terminals E2 and VC on EGR position sensor. (Scheme 318) 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 319) See «ECM TERMINAL APPLICATION»(ref-91239-S24507982762001030600000) 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 320) See «ECM TERMINAL APPLICATION»(ref-91239-S24507982762001030600000) table for E2 and EGLS terminal wire 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 317

Scheme 318

Scheme 319

EGR VACUUM CONTROL VALVE

Note. EGR vacuum control valve may also be referred to as 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 314)
2. Plug port "Z" and connect vacuum pump to port "S" on EGR vacuum control valve. (Scheme 321)
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 if vacuum reading is not within specification.

Scheme 320

Scheme 321

1. Remove "V" bank cover and emission control valve set located on top of engine for access to EGR VSV. (Scheme 242)
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. see scheme 102
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. see scheme 102 Replace EGR VSV if defective. Reinstall EGR VSV.

1. Remove EGR valve. See EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 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 Evaporative (EVAP) system may contain different components depending on application. (Scheme 314)- (Scheme 317). When testing fuel EVAP system components, it may be necessary to use proper illustration to determine component location.

Note. On Avalon, Camry and Camry Solara, an On-Board Refilling Vapor Recovery (ORVR) system is used to recover fuel vapors into charcoal canister that are generated during refueling. ORVR system consists of fuel inlet pipe, overfill check valve, cut-off valve and charcoal canister. (Scheme 314) Overfill check valve may also be referred to as On-Board Refueling Vapor Recovery Overfill Check Valve (ORVR-OCKV) or fill check valve. Cut-off valve may also be referred to On-Board Refueling Vapor Recovery Cut-Off Valve (ORVR-COV). For testing of fuel EVAP system and ORVR system, see appropriate FUEL EVAP SYSTEM TEST.

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

Charcoal Canister

For testing of charcoal canister, see appropriate FUEL EVAP SYSTEM TEST.

EVAP Vacuum Switching Valve

1. Remove EVAP Vacuum Switching Valve (VSV). (Scheme 314)- (Scheme 317). See «EVAP VSV LOCATIONS»(ref-91239-S08933199522001030600000) table. 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, Camry Solara & 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 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 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-91239-S28334448672001030600000) 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, Camry Solara & Sienna 27-33 Land Cruiser & Tacoma 30-34 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 323)and (Scheme 324).
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 323)and (Scheme 324). Replace EVAP VSV if defective.

Scheme 322

Scheme 323

Scheme 324

Scheme 325

Scheme 326

Scheme 327

Scheme 328

Scheme 329

Scheme 330

Scheme 331

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, disconnect electrical connector at vapor pressure sensor. (Scheme 314)- (Scheme 317). See «VAPOR PRESSURE SENSOR LOCATION»(ref-91239-S40778647032001030600000) table. VAPOR PRESSURE SENSOR LOCATION Application Location Avalon On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With Brown, Pink & Blue/Red Wires Camry On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With Brown, Pink & Yellow Wires Camry Solara On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With Brown, Blue/Red & Yellow Wires Land Cruiser 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 4Runner On Firewall, Above Brake Booster & Contains Black 3-Pin Electrical Connector With Brown/Black Or Blue/Black, Green/Black & Yellow 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. (Scheme 325)- (Scheme 329).
5. Obtain access to Engine Control Module (ECM). See «ECM LOCATION»(ref-91239-S42939549722001030600000) table. Connect voltmeter between specified ECM terminals. (Scheme 330)- (Scheme 332). See «ECM TERMINAL APPLICATION»(ref-91239-S30501782632001030600000) table. ECM LOCATION Model (1) Location Avalon, Camry & Camry Solara Behind Glove Box Land Cruiser Above Glove Box, Near Passenger's Side Of Instrument Panel Sienna Passenger's Side Of Instrument Panel, Just Below Glove Box Tacoma & 4Runner Behind Glove Box (1) For illustration of ECM location, see THEORY & OPERATION article. ECM TERMINAL APPLICATION Application & Terminal Wire Color Avalon & Camry E2 Brown PTNK Pink Camry Solara E2 Brown PTNK Blue/Red Land Cruiser E2 Brown/White PTNK Blue/Black Sienna E2 Brown PTNK Blue/Red Tacoma E2 Brown/Black PTNK Red/Yellow 4Runner E2 Brown/Black Or Blue/Black PTNK Yellow
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-91239-S21960844562001030600000) table.
7. Release vacuum from vapor pressure sensor. Ensure output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-91239-S21960844562001030600000) 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-91239-S21960844562001030600000) table. Replace vapor sensor if output voltage is not within specification. Reconnect vacuum hose. VAPOR SENSOR OUTPUT VOLTAGE Condition Output Voltage Vacuum Applied 1.3-2.1 Vacuum Released 3.0-3.6 Pressure Applied 4.2-4.8

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 314)- (Scheme 317).
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-91239-S19461394482001030600000) 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 & Camry Solara 33-39 Land Cruiser, Sienna, Tacoma & 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 333)- (Scheme 335).
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 333)- (Scheme 335). Replace vapor pressure sensor VSV if defective.

Scheme 332

Scheme 333

Scheme 334

POSITIVE CRANKCASE VENTILATION (PCV)

1. Avalon, Camry, Camry Solara, Land Cruiser & Sienna Remove PCV valve. See «PCV VALVE LOCATION»(ref-91239-S08376552982001030600000) table.
2. Apply air pressure to PCV valve at cylinder head side of PCV valve. Ensure air flows easily through PCV valve. 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. Tacoma & 4Runner Remove PCV valve. See «PCV VALVE LOCATION»(ref-91239-S08376552982001030600000) table.
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.

PCV VALVE LOCATION

Tacoma 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 ON-VEHICLE ADJUSTMENTS - V6 & V8 article. Shut engine off. Remove cap, filter and separator from dashpot on throttle body. (Scheme 336)
2. Start engine. Maintain engine speed at 2500 RPM. Plug Vacuum Transmitting Valve (VTV) hole in dashpot with your finger. (Scheme 337)
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 338)
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 335

Scheme 336

Scheme 337

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 article.
2. Shut engine off. Disconnect and plug vacuum hose at throttle opener near throttle body. (Scheme 339)- see scheme 131. 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 338

Scheme 339

Scheme 340

Scheme 341