System /component Tests Toyota Camry V30

INTRODUCTION

Before testing separate components or systems, perform procedures in BASIC TESTING article in the ENGINE PERFORMANCE Section. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in TESTS W/CODES article in the ENGINE PERFORMANCE Section.

Note. Testing individual components does not isolate shorts or opens. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

Note. When testing some systems, tachometer may be required. Tachometer must be connected to proper terminals. For tachometer connections, see IDLE SPEED & MIXTURE in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.

Scheme 116

Scheme 117

1. Using a 3-way connector, connect vacuum gauge to actuator valve. (Scheme 116) 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 does not pull inward, proceed to step 3).
3. Disconnect vacuum hose from actuator valve. Using vacuum pump, apply approximately 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 and proceed to step 4).
4. Disconnect vacuum hoses from vacuum tank, located near driver's side headlight in engine compartment. Apply air pressure to port "B" on vacuum tank and ensure air passes out port "A". (Scheme 117) Apply air pressure to port "A" and ensure air does not pass out port "B". (Scheme 117)
5. Plug port "B" on vacuum tank. Using vacuum pump, apply approximately 8 in. Hg of vacuum to port "A". (Scheme 117) 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 and proceed to step 6).
6. Disconnect electrical connectors from IACV Vacuum Switching Valve (VSV), located near valve cover. (Scheme 118) Using ohmmeter, ensure continuity exists between electrical terminals on VSV. Check that no continuity exists between each electrical terminal and the body of the VSV.
7. Apply air pressure to port "B" and ensure air passes out the filter. (Scheme 119) Connect battery voltage to VSV terminals. Apply air pressure to port "B" and ensure air passes out port "A". (Scheme 119) Replace VSV if defective and recheck system operation. If VSV is okay, proceed to step 8).
8. Turn ignition on. Check for battery voltage at Black/Orange wire of VSV electrical connector. If battery voltage exists, replace Electronic Control Unit (ECU). If battery voltage does not exist, check EFI main relay. See EFI MAIN RELAY under RELAYS.
9. If EFI main relay is okay, check wiring. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. Repair as necessary and recheck system operation.

Scheme 118

Scheme 119

AIRFLOW METER (EXCEPT 2.2L)

1. Turn ignition off. Disconnect electrical connector from airflow meter. Note location of air-flow meter components and terminal identification. (Scheme 120)and (Scheme 121).
2. Using ohmmeter, measure resistance between specified terminals. See «AIRFLOW METER RESISTANCE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace airflow meter if resistance is not within specification.

AIRFLOW METER RESISTANCE SPECIFICATIONS

Scheme 120

Scheme 121

Note. Air temperature sensor may be referred to as intake air temperature sensor.

AIR TEMPERATURE SENSOR (2.2L)

1. Ensure ignition is off. Disconnect electrical connector from air temperature sensor. Air temperature sensor is located in the air intake, near the air filter.
2. Using ohmmeter, measure resistance between air temperature sensor electrical terminals. Replace air temperature sensor if resistance is not within specification in relation to the temperature. (Scheme 122)

Scheme 122

COLD START INJECTOR TIME SWITCH (3.0L)

1. Ensure ignition is off. Disconnect electrical connector from cold start injector time switch. Cold start injector time switch is located in engine coolant passage near cylinder head or thermostat housing. It may be necessary to verify wire colors for proper identification. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. NOTE: Cold start injector time switch may also be identified by appropriate illustration in THEORY/OPERATION article in the ENGINE PERFORMANCE Section.
2. Note cold start injector terminal identification. (Scheme 123) Using ohmmeter, measure resistance at designated switch terminals at specified temperature. See «COLD START INJECTOR TIME SWITCH RESISTANCE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace cold start injector time switch if resistance is not within specification.

COLD START INJECTOR TIME SWITCH RESISTANCE SPECIFICATIONS

Scheme 123

COOLANT TEMPERATURE SENSOR

1. Ensure ignition is off. Disconnect electrical connector from Coolant Temperature Sensor (CTS). The CTS is located in engine coolant passage near cylinder head or thermostat housing. It may be necessary to verify wire colors for proper identification. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. NOTE: The CTS may be also identified by appropriate illustration in THEORY/OPERATION article in the ENGINE PERFORMANCE Section.
2. Using ohmmeter, check resistance between CTS electrical terminals. Resistance should be within specification at designated temperature. (Scheme 124) Replace CTS if resistance is not within specification.

Scheme 124

EGR GAS TEMPERATURE SENSOR (CALIF. ONLY)

1. Remove EGR gas temperature sensor from side of EGR valve. Place threaded end of sensor and thermometer in container of oil. (Scheme 125)
2. Attach ohmmeter to electrical terminals. Heat oil and note resistance at specified temperature. See «EGR GAS TEMPERATURE SENSOR SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace EGR gas temperature sensor if resistance is not within specification.

EGR GAS TEMPERATURE SENSOR SPECIFICATIONS

Scheme 125

KNOCK SENSOR

On models equipped with Knock Sensor (KS), use diagnosis in Code 52 and 53 charts. Some models only have Code 52. For code charts, see TESTS W/CODES article in the ENGINE PERFORMANCE Section.

MANIFOLD ABSOLUTE PRESSURE SENSOR

See VACUUM SENSOR (2.2L) .

NEUTRAL/START SWITCH

Disconnect electrical connector from neutral/start switch at transmission or transaxle. Note terminal identification. (Scheme 126) Using ohmmeter, check for continuity at specified terminals with gearshift in proper positions. See NEUTRAL/START SWITCH SPECIFICATIONS table. Replace neutral/start switch if defective.

NEUTRAL/START SWITCH SPECIFICATIONS

Scheme 126

OXYGEN SENSOR FEEDBACK VOLTAGE TEST

1. Warm engine to normal operating temperature. Connect analog voltmeter to engine check connector VF1 or VF2 and E1 terminals. (Scheme 127)- (Scheme 129). Perform procedures listed in (Scheme 130) and (Scheme 131).
2. Depending on model application, some vehicles may be equipped with a main oxygen sensor, sub-oxygen sensor and a sensor heater. See «OXYGEN SENSOR APPLICATION»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.

Note. Codes 21, 25, 26, 27 and 28 are oxygen sensor circuit codes. For code charts, see TESTS W/CODES article in the ENGINE PERFORMANCE Section.

OXYGEN SENSOR APPLICATION

Scheme 127

Scheme 128

Scheme 129

Scheme 130

Scheme 131

SUB-OXYGEN SENSOR

1. Warm engine to normal operating temperature. Check ECU for stored code(s). See RETRIEVING CODES in TESTS W/CODES article in the ENGINE PERFORMANCE Section. If sub-oxygen sensor or circuit fails, a Code 27 will set in ECU memory. Clear codes if present. See CLEARING CODES in TESTS W/CODES article in the ENGINE PERFORMANCE Section.
2. Drive vehicle at speeds less than 50 MPH for at least 5 minutes in 4th or 5th gear (M/T) or Drive (A/T). On all models, fully depress accelerator pedal for at least 2 seconds.
3. Stop engine and turn ignition off. Repeat steps and note if Code 27 exists again. If Code 27 exists again, check sub-oxygen sensor circuit for continuity, shorts or grounds. Replace sub-oxygen sensor if circuit is okay.

Note. For oxygen sensor heater or sub-oxygen sensor heater application, see OXYGEN SENSOR APPLICATION table.

Note. A Code 21 is also an indicator of a problem in oxygen sensor circuit. Code 21 will set if sensor heater circuit opens or shorts to ground on HT wire from sensor to Electronic Control Unit (ECU).

OXYGEN SENSOR OR SUB-OXYGEN SENSOR HEATER

1. Disconnect electrical connector from the sensor. Using an ohmmeter, measure resistance between sensor terminals +B and HT. (Scheme 132)
2. Replace sensor if resistance is not within specification. See «OXYGEN SENSOR HEATER RESISTANCE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.

OXYGEN SENSOR HEATER RESISTANCE SPECIFICATIONS

Scheme 132

THROTTLE POSITION SENSOR

1. Turn ignition off. Disconnect electrical connector from Throttle Position Sensor (TPS) on throttle body. Note terminal identification. (Scheme 133)
2. Insert specified thickness feeler gauge between throttle stop screw and throttle lever, and check resistance or continuity. See appropriate «TPS RESISTANCE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace or adjust TPS if not within specification.

Note. Some models require that vacuum be applied to throttle opener before checking TPS. See appropriate TPS RESISTANCE SPECIFICATIONS table.

Scheme 133

TPS RESISTANCE SPECIFICATIONS

Note. Vacuum sensor may also be referred to as Manifold Absolute Pressure (MAP) sensor.

VACUUM SENSOR (2.2L)

1. Ensure ignition is off. To check vacuum sensor supply voltage, disconnect electrical connector from vacuum sensor.
2. On all other models, vacuum sensor is located on center of firewall. NOTE: Vacuum sensor has a vacuum hose connected to it and may be identified by wire colors. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.
3. Turn ignition on. Using voltmeter, measure voltage between terminals VCC and E2 of harness connector. (Scheme 134) Voltage should be within specification. See «VACUUM SENSOR SUPPLY VOLTAGE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. VACUUM SENSOR SUPPLY VOLTAGE SPECIFICATIONS Application Voltage 2.2L 4.75-5.25
4. If supply voltage is not within specification, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. If supply voltage is correct, turn ignition off and reinstall electrical connector on vacuum sensor.
5. To check vacuum sensor output voltage, turn ignition on. Disconnect vacuum sensor vacuum hose from intake manifold. Connect voltmeter to terminals PIM and E2 of Electronic Control Unit (ECU). (Scheme 135)and (Scheme 136). See «ECU LOCATION»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. ECU LOCATION Application Location Camry Behind Glove Box
6. Measure and record output voltage under ambient atmospheric pressure. Attach vacuum pump to vacuum sensor.
7. Apply vacuum in specified increments and measure output voltage drop at each increment. See «VACUUM SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace vacuum sensor if output voltage drop is not within specification.

VACUUM SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS

Scheme 134

Scheme 135

Scheme 136

VEHICLE SPEED SENSOR

1. Vehicle Speed Sensor (VSS) is located on rear of combination meter in instrument cluster. Connect voltmeter and battery voltage to vehicle speed sensor terminals. (Scheme 137)- (Scheme 139).
2. While rotating speedometer shaft, ensure voltage changes from zero to at least 11 volts. Voltage should change approximately 20 times per revolution of speedometer shaft. Replace vehicle speed sensor if voltage does not change as specified.

Scheme 137

Scheme 138

Scheme 139

CIRCUIT OPENING RELAY

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Using ohmmeter, check continuity between specified terminals. (Scheme 140)- (Scheme 143).
2. Check circuit opening relay operation by applying battery voltage and checking continuity between specified terminals. (Scheme 140)- (Scheme 143). Replace circuit opening relay if defective.

Note. Circuit opening relay may also be identified by appropriate illustration in THEORY/OPERATION article in the ENGINE PERFORMANCE Section or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.

CIRCUIT OPENING RELAY LOCATION

Scheme 140

Scheme 141

Scheme 142

Scheme 143

EFI MAIN RELAY

1. Ensure ignition is off. Remove EFI main relay. See «EFI MAIN RELAY LOCATION»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Using ohmmeter, check continuity between specified terminals. (Scheme 144)
2. Check EFI main relay operation by applying battery voltage and checking continuity between specified terminals. (Scheme 144) Replace EFI main relay if defective.

Note. The EFI main relay may also be identified by appropriate illustration in THEORY/OPERATION article in the ENGINE PERFORMANCE Section or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.

EFI MAIN RELAY LOCATION

Scheme 144

FUEL CONTROL

Note. Fuel injector solenoid resistor may also be referred to as solenoid resistor.

Fuel Injectors

1. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, measure resistance between fuel injector electrical terminals. Replace fuel injector if resistance is not within specification. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.
2. To check fuel injector spray pattern and volume, remove fuel injectors. See N - REMOVE/INSTALL/OHAUL article in the ENGINE PERFORMANCE Section. Disconnect fuel hose from fuel filter outlet. Use Delivery Hose (09268-41045) to install fuel injector between fuel filter and fuel pressure regulator. (Scheme 145)
3. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage. Connect jumper wire between terminals FP and +B of engine check connector. Turn ignition on, with engine off to pressurize fuel system. NOTE: For proper location of engine check connector and terminal identification, see TESTS W/CODES article in the ENGINE PERFORMANCE Section. Jumper wire is installed in engine check connector when checking fuel operation and fuel pressure.
4. Connect fuel injector tester to fuel injector for 15 seconds. Use Fuel Injector Tester (09842-30070) for all others.
5. Measure fuel injector volume and check spray pattern. Test each fuel injector 2-3 times. Replace fuel injector if volume is not as specified. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. NOTE: Ensure the difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.
6. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector is one drop or less in one minute. Replace fuel injector if leakage exceeds specified amount. Turn ignition off and remove test equipment.

FUEL INJECTOR RESISTANCE SPECIFICATIONS

FUEL INJECTOR VOLUME SPECIFICATIONS

Scheme 145

Note. Fuel pressure control system may also be referred to as fuel-pressure up system.

Fuel Pressure Control System (3.0L)

1. Ensure coolant temperature sensor operates correctly. See «ENGINE SENSORS & SWITCHES»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests). NOTE: ECU uses signal from coolant temperature sensor to control ground circuit for fuel pressure control VSV.
2. VSV is supplied voltage through EFI main relay. The ECU will activate VSV for approximately 90 seconds when restarting engine at normal operating temperature. Locate and remove fuel pressure control VSV. See «FUEL PRESSURE CONTROL VSV LOCATION»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. NOTE: Fuel pressure control VSV may also be identified by appropriate illustration in THEORY/OPERATION article in the ENGINE PERFORMANCE Section or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. FUEL PRESSURE CONTROL VSV LOCATION Application Location 3.0L On Top Of Intake Manifold Cover, Near Driver's Side
3. Use ohmmeter to check continuity between VSV electrical terminals. Ensure resistance is within specification. See «FUEL PRESSURE CONTROL VSV RESISTANCE SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.
4. Check that no continuity exists between each electrical terminal and VSV body. Replace VSV if resistance is not within specification or continuity exists between electrical connector and VSV body.
5. Test VSV by applying air pressure to designated area and checking air passage, and then applying battery voltage and retesting. (Scheme 146) Replace VSV if defective.

FUEL PRESSURE CONTROL VSV RESISTANCE SPECIFICATIONS

Scheme 146

Scheme 147

Fuel Cut System

1. Install tachometer. Tachometer must be connected to proper terminals. See IDLE SPEED & MIXTURE in ADJUSTMENTS article in the ENGINE PERFORMANCE Section. CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. To avoid possible damage to ignitor and/or coil, DO NOT allow tachometer terminal to become grounded.
2. Start engine and warm to normal operating temperature. Ensure all accessories are off. Gradually increase engine RPM to at least 2500 RPM.
3. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily (fuel cut RPM) and then resumes operating (fuel return RPM).
4. Ensure fuel return RPM is within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Shut engine off and disconnect tachometer.

FUEL CUT SYSTEM SPECIFICATIONS

Cold Start Injector (3.0L)

1. Disconnect negative battery cable. Disconnect cold start injector wiring harness connector.
2. Using ohmmeter, measure resistance between electrical terminals of cold start injector. Replace cold start injector if resistance is not 2-4 ohms.
3. Remove cold start injector. Install Union Adapters (09268-41080) on cold start injector and delivery pipe. Connect delivery hose to union adapters. (Scheme 148)
4. Reconnect negative battery cable. Connect jumper wire between terminals FP and +B of engine check connector. Turn ignition on, with engine off to pressurize fuel system. NOTE: For proper location of engine check connector and terminal identification, see TESTS W/CODES article in the ENGINE PERFORMANCE Section. Jumper wire is installed in engine check connector when checking fuel operation and fuel pressure.
5. Connect cold start injector tester to cold start injector. Use Cold Start Injector Tester (09842-30055) for Camry 3.0L, or (09842-30050) for all others. Place cold start injector in a container. CAUTION: Perform cold start injector test in shortest possible time to check fuel spray pattern.
6. Connect cold start injector tester to battery. Ensure fuel spray pattern is an even cone shape. Disconnect cold start injector tester from battery.
7. Note fuel leakage from cold start injector. Maximum leakage should be one drop per minute with fuel pressure applied. Replace cold start injector if defective. Disconnect negative battery cable and test equipment.

Note. Cold start injector is controlled by cold start injector time switch when ignition is turned on.

Cold Start Injector Time Switch

For test procedures, see ENGINE SENSORS & SWITCHES .

Scheme 148

AUXILIARY AIR VALVE SYSTEM

Note. Tachometer must be installed when checking auxiliary air valve system. Tachometer must be connected to proper terminals. See IDLE SPEED & MIXTURE in ADJUSTMENTS article in the ENGINE PERFORMANCE Section for tachometer connections.

2.2L

1. Warm engine to normal operating temperature. Ensure idle speed is correct. See ADJUSTMENTS article in the ENGINE PERFORMANCE Section.
2. Apply parking brake and place transmission/transaxle in Neutral. Install jumper wire between terminals TE1 and E1 of engine check connector. (Scheme 149)
3. Engine RPM should increase to 1000-1300 RPM (Camry) for 5 seconds, and then return to idle.
4. If engine RPM is not as specified, check Idle Speed Control (ISC) valve, wiring to ECU, ECU grounds and ECU. If engine RPM was within specification, remove jumper wire. Turn ignition off.
5. To check ISC valve resistance, disconnect electrical connector from ISC valve on lower edge of throttle body. Using ohmmeter, measure resistance between terminal B+ and each remaining terminal. (Scheme 150)
6. Replace ISC valve if resistance is not within specification. See «ISC VALVE RESISTANCE SPECIFICATIONS (EXCEPT 3.0L)»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.
7. Remove ISC valve to check ISC valve operation. Connect battery to proper terminals and ensure valve opens and closes. (Scheme 151)and (Scheme 152). Replace ISC valve if defective.

ISC VALVE RESISTANCE SPECIFICATIONS (EXCEPT 3.0L)

Scheme 149

Scheme 150

Scheme 151

Scheme 152

3.0L

1. Listen for clicking sound at ISC valve immediately after engine is shut off. The ISC valve is located on air intake chamber, near throttle body.
2. If no sound is heard, check ISC valve and wiring circuit between Electronic Control Unit (ECU) and ISC valve. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. The ECU is located near the glove box.
3. To check ISC valve resistance, ensure ignition is off. Disconnect electrical connector from ISC valve. Note ISC valve terminals. (Scheme 153)
4. Using ohmmeter, measure resistance between specified terminals. See «ISC VALVE RESISTANCE SPECIFICATIONS (3.0L)»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace ISC valve if resistance is not within specification. ISC VALVE RESISTANCE SPECIFICATIONS (3.0L) Terminals Ohms B1 To S1 Or S3 10-30 B2 To S2 Or S4 10-30 NOTE: Before removing ISC valve, drain coolant from cooling system. Remove both coolant by-pass hoses.
5. To check ISC valve operation, remove ISC valve. Apply battery voltage to terminals B1 and B2. (Scheme 154)and (Scheme 155). Repeatedly ground terminals in sequence and ensure ISC valve closes and opens. See «ISC VALVE GROUNDING SEQUENCE»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Replace ISC valve if defective.

ISC VALVE GROUNDING SEQUENCE

Scheme 153

Scheme 154

Scheme 155

IGNITION SYSTEM

Note. For basic ignition checks, see BASIC TESTING article in the ENGINE PERFORMANCE Section.

PICK-UP COILS

See PICK-UP COIL AIR GAP and PICK-UP COIL RESISTANCE in BASIC TESTING article in the ENGINE PERFORMANCE Section.

On models equipped with knock sensor, see CODE 52 and CODE 53 charts in TESTS W/CODES article in the ENGINE PERFORMANCE Section for diagnosis.

EXHAUST GAS RECIRCULATION (EGR)

Note. EGR systems contain different components and have different operating parameters depending on application. (Scheme 156)- (Scheme 159). When testing EGR system and components, use proper illustration to determine component location.

EGR System Test (2.2L)

1. Ensure EGR vacuum modulator filter is clean and in good condition. Clean filter with compressed air (if necessary).
2. Using "T" connector, install vacuum gauge in vacuum line to EGR valve. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve.
3. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 of data link connector No. 1, located in engine compartment. NOTE: The EGR system components can be checked with engine coolant temperature less than minimum temperature and engine at specified engine RPM.
4. Operate engine with engine coolant temperature less than minimum temperature and at specified RPM. See «EGR TESTING SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. No vacuum reading should be obtained.
5. Warm engine to normal operating temperature. Operate engine at specified engine RPM again. See «EGR TESTING SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Ensure a low vacuum reading is now obtained.
6. Disconnect vacuum hose from port "R" of EGR vacuum modulator. (Scheme 156)and (Scheme 157). Using additional hose, connect port "R" of EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See «EGR TESTING SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
7. Remove vacuum hose and reconnect original vacuum hose to EGR vacuum modulator. To check EGR valve operation, remove vacuum hose from EGR valve.
8. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested. Shut engine off. Remove jumper wire from data link connector No. 1.

EGR System Test (3.0L)

1. Ensure EGR vacuum modulator filter(s) are clean and in good condition. Clean filter(s) with compressed air (if necessary).
2. Using "T" connector, install vacuum gauge in vacuum line to EGR valve. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve. NOTE: The EGR system components can be checked with engine coolant temperature less than minimum temperature and engine at specified engine RPM.
3. Operate engine with engine coolant temperature less than minimum temperature and at specified RPM. See «EGR TESTING SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. No vacuum reading should be obtained.
4. Warm engine to normal operating temperature. Operate engine at specified engine RPM again. See «EGR TESTING SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Ensure a low vacuum reading is now obtained.
5. On all models except Celica Turbo, MR2 Turbo and Supra Turbo, disconnect vacuum hose from port "R" of EGR vacuum modulator. (Scheme 156)and (Scheme 157).
6. Using additional hose, connect port "R" of EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See «EGR TESTING SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
7. Remove vacuum hose and reconnect original vacuum hose to EGR vacuum modulator.
8. On all models, to check EGR valve operation, remove vacuum hose from EGR valve. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested.

EGR TESTING SPECIFICATIONS

EGR Vacuum Modulator

1. EGR vacuum modulator may be a 2-port or 3-port type depending on application. On 2-port models, disconnect hoses from vacuum modulator. Plug one end of vacuum hose connection on EGR vacuum modulator.
2. Apply air pressure through remaining port. Air should pass freely through air filter side of modulator. On 3-port models, disconnect all hoses. Block ports "P" and "R". Apply air pressure to port "Q". (Scheme 156) Air should pass through the air filter side of modulator freely.
3. Operate engine at specified RPM. See «EGR VACUUM MODULATOR SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Repeat test procedures in steps 1) and 2). Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt. Reconnect vacuum hoses to proper locations.

EGR VACUUM MODULATOR SPECIFICATIONS

Scheme 156

BVSV SPECIFICATIONS

VACUUM SWITCHING VALVE (VSV) SPECIFICATIONS

Vacuum Switching Valve (VSV) (2.2L)

1. Unplug VSV connector. (Scheme 160) Connect battery to VSV terminals. (Scheme 157) Apply air pressure to port "E". Air should pass through air filter. Disconnect battery terminals.
2. Apply air pressure to port "E". Air should now pass through port "G". Using ohmmeter, check for continuity between terminals and VSV body. Replace unit if incorrect airflow or continuity exists.
3. Using ohmmeter, measure resistance between both terminals of valve assembly. Replace valve if resistance is not within specification. See «VACUUM SWITCHING VALVE (VSV) SPECIFICATIONS»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table.

Scheme 157

Scheme 158

EGR System Components & Operating Parameters (3.0L) Id. Scheme 159

Scheme 160

EGR System Components & Operating Parameters (2.2L) Id. Scheme 161

FUEL EVAPORATION

Note. (Scheme 162)to identify evaporative emission control systems and operating parameters.

Fuel Odor Or Gas Leaks

Check for disconnected or cracked fuel vapor line or defective components in system. Check all lines and fittings. Check operation of system.

Fuel Tank Or Expansion Tank Deformed

Check for clogged canister, defective vacuum relief filler cap or restricted hoses.

Rough Engine Operation

Check vacuum hose between vacuum solenoid valve (if equipped) and intake manifold for damage or loose connections. Check for malfunctions in all valves. Ensure all vacuum hoses are tight and in good condition.

Bimetallic Vacuum Switching Valve (BVSV)

1. Drain engine coolant. Remove BVSV. Connect hose to top port. Place valve in water that is less than 95°F (35°C). Blow air into hose. Ensure valve is closed.
2. Heat water to 129°F (54°C). Blow air into hose. Ensure valve is open. If valve is not open, replace valve. Apply liquid sealer to threads of valve before installing. Fill cooling system. If BVSV does not operate as described, replace valve.

Charcoal Canister

1. Check for clogged filter and/or stuck check valve by blowing low pressure compressed air into canister tank port. Ensure air flows freely out of other canister ports.
2. Blow air into canister purge port. Ensure air does not flow out of any other port.

Maintenance

1. Inspect fuel tank, canister, vacuum relief filler cap, lines and hoses for damage, leaks and deterioration every 60,000 miles or every 6 years. Replace gasket in vacuum relief filler cap.
2. To clean charcoal canister filter, remove hoses from canister and apply 43 psi (3 kg/cm 2 ) air pressure to fuel tank port. Hold other top ports closed. Ensure no carbon comes out of bottom port of canister.

Scheme 162

Evaporative Emission Control System & Operating Parameters Id. Scheme 163

Fixed Orifice

Visually inspect hose and connections for cracks, leaks or other damage. Clean deposits from orifice with solvent and blow out with compressed air.

PCV Valve

Remove PCV valve. Attach hose to PCV valve. Blow air from cylinder head side of valve. Ensure air passes through easily. Blow air from intake manifold side. Ensure air passes through with some restriction. If PCV valve does not function as described, replace PCV valve.

DASHPOT CONTROL SYSTEM

1. Engine must be at normal operating temperature. Check idle speed and adjust if necessary. Remove cap, filter and separator from dashpot. (Scheme 164)
2. Start engine. Maintain engine speed at specified testing RPM. See «DASHPOT TESTING RPM»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. Plug Vacuum Transmitting Valve (VTV) hole with your finger. (Scheme 164)
3. Release throttle. Dashpot should be extended and dashpot setting RPM should be as specified. See «DASHPOT TESTING RPM»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. If idle speed is incorrect, adjust dashpot. (Scheme 165)
4. To check VTV operation, run engine at dashpot testing RPM for a few seconds. Plug the VTV hole with your finger. Release throttle. Uncover plugged hole. Engine should return to idle in about one second. Install dashpot separator, filter and cap. Install filter with coarser surface facing outward.

DASHPOT TESTING RPM

Scheme 164

Scheme 165

THROTTLE VALVE OPENER (3.0L)

1. Engine must be at normal operating temperature. Ensure idle speed is correct. Disconnect vacuum hose from throttle valve opener and plug hose. (Scheme 166) Raise engine speed to 2500 RPM.
2. Release throttle valve. Check throttle valve opener RPM. See «THROTTLE VALVE OPENER RPM»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. If throttle valve opener RPM is not as specified, replace throttle body.

THROTTLE VALVE OPENER (2.2L)

1. Engine must be at normal operating temperature. Ensure idle speed is correct. Disconnect vacuum hose from throttle valve opener and plug hose. (Scheme 166) Raise engine speed to 2500 RPM.
2. Release throttle valve. Check throttle valve opener RPM. See «THROTTLE VALVE OPENER RPM»(/toyota/camry/v30-1990-1994/remont/testing-diagnostics/#system-component-tests) table. If throttle valve opener RPM is not as specified, adjust throttle valve opener set screw to obtain correct RPM. (Scheme 166) Reconnect vacuum hose.

THROTTLE VALVE OPENER RPM

Scheme 166

See also:
• AIRFLOW METER RESISTANCE SPECIFICATIONS
• VACUUM SENSOR (2.2L)