Engine Controls - System/component Tests: Other Toyota Camry XV10

AIRFLOW METER

Turn ignition off. Unplug wiring connector from airflow meter. Note terminal identification. (Scheme 126) Use ohmmeter to measure resistance between specified terminals. See AIRFLOW METER RESISTANCE SPECIFICATIONS table. Replace airflow meter if not within specification.

Scheme 125

Scheme 126

AIRFLOW METER RESISTANCE SPECIFICATIONS

COLD START INJECTOR TIME SWITCH

Turn ignition off. Remove connector from switch. (Scheme 127)and (Scheme 128) for Time Switch Location. Measure resistance across switch terminals at specified temperature. (Scheme 129) Replace switch if resistance is not within specification. See COLD START INJECTOR TIME SWITCH RESISTANCE SPECIFICATIONS table.

COLD START INJECTOR TIME SWITCH RESISTANCE SPECIFICATIONS

Scheme 127

Scheme 128

Scheme 129

COOLANT TEMPERATURE SENSOR

1. Ensure ignition is off. Unplug connector from sensor. For sensor location (Scheme 127)and (Scheme 128).
2. Using ohmmeter, check resistance between sensor terminals. Replace sensor if resistance is not within specification at specified temperature. (Scheme 130)

Scheme 130

EGR GAS TEMPERATURE SENSOR

1. Remove sensor from side of EGR valve. Place threaded end of sensor and thermometer in container of oil. (Scheme 131)
2. Attach ohmmeter to sensor terminals. Heat oil and note resistance at specified temperature. See «EGR TEMPERATURE SENSOR SPECIFICATIONS»(ref-21027-S11154650482001010300000) table. Replace sensor if not within specification.

EGR TEMPERATURE SENSOR SPECIFICATIONS

Scheme 131

KNOCK SENSOR (2.5L)

Probable causes of knock sensor problems include the following

1. Open or short in knock sensor circuit.
2. Knock sensor (looseness etc.).
3. Knock control in ECU is faulty.

Knock sensor problems can also set fault codes 52 and 53. For code charts, see TESTS W/ CODES article.

NEUTRAL/START SWITCH

Unplug switch connector at transmission or transaxle. Note terminal identification. (Scheme 132) Using ohmmeter, check for continuity at specified terminals with gearshift in correct range. See NEUTRAL/START SWITCH SPECIFICATIONS table.

NEUTRAL/START SWITCH SPECIFICATIONS

Scheme 132

SUB-OXYGEN SENSOR (CALIF. ONLY)

1. Warm engine to normal operating temperature. Check ECU for stored fault code(s). If sub-oxygen sensor or circuit fails, a Code 27 fault code will set in ECU memory. Clear codes if present. See CLEARING TROUBLE CODES in appropriate TESTS W/ CODES article. NOTE: DO NOT drive vehicle more than 62 MPH or code will cancel.
2. Drive vehicle between 50 and 61 MPH for at least 5 minutes in 4th or 5th gear (M/T) or Drive (A/T).
3. Fully depress accelerator pedal for at least 10 seconds with engine RPM at least 3000 RPM. Stop engine and turn ignition off.
4. Repeat previous 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.

OXYGEN (O2) SENSOR HEATER (2.5L ONLY)

1. Unplug O2 sensor connector. Using ohmmeter, measure resistance between sensor terminals. +B and HT. (Scheme 133) Replace sensor if resistance is not within 5.1-6.3 Ohms.
2. A Code No. 21 is also an indicator of a problem in O2 sensor circuit. Code No. 21 will set if O2 sensor heater circuit opens or shorts to ground on HT wire from sensor to ECU.

Scheme 133

PICK-UP COILS

See PICK-UP AIR GAP and PICK-UP COIL RESISTANCE in appropriate BASIC TESTING article.

THROTTLE POSITION SENSOR

Turn ignition off. Unplug electrical connector at Throttle Position Sensor (TPS) on throttle body. Note terminal identification. (Scheme 134)- (Scheme 136). Insert specified thickness feeler gauge between throttle stop screw and throttle lever. See TPS RESISTANCE SPECIFICATIONS table. Using an ohmmeter, check for resistance or continuity. Replace or adjust TPS if not within specification.

TPS RESISTANCE SPECIFICATIONS

Scheme 134

Scheme 135

Scheme 136

VEHICLE SPEED SENSOR

1. Remove combination meter from instrument cluster. Connect ohmmeter between terminals "A" and "B". (Scheme 137)
2. Rotate meter shaft and note reading. Ohmmeter should deflect from continuity to no continuity 4 times per revolution as shaft is rotated. If ohmmeter does not deflect as specified, replace speed sensor.

Scheme 137

CIRCUIT OPENING RELAY

Relay is located under ECU, under center of dash. To check circuit opening relay (Scheme 138)and (Scheme 139). Replace relay if continuity is not as specified.

Note. During cranking, there should be 12 volts present at FP terminal of circuit opening relay. This is the fuel pump (or fuel pump relay) line. See appropriate WIRING DIAGRAMS article for wire color.

Scheme 138

Scheme 139

EFI MAIN RELAY

EFI main relay is located in relay bank, on left front fenderwell. To test EFI main relay (Scheme 140) Replace relay if defective.

Scheme 140

FUEL PUMP RELAY

See FUEL DELIVERY under FUEL SYSTEM for testing.

FUEL SYSTEM

Fuel Pressure Release

Disconnect negative battery terminal. Place container under fitting to be loosened. Use a rag to cover fuel line/component. Slowly loosen fitting, allowing pressurized fuel to spill into container. After fuel system has depressurized, disconnect and plug fitting.

FUEL DELIVERY

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

Fuel Injectors

1. Turn ignition off. Unplug each injector connector. Measure resistance across both terminals. If resistance is not 13.8 Ohms measured at 68°F (20°C) replace fuel injector.
2. To check injector spray pattern and volume, relieve fuel system pressure. Remove injectors from engine. Disconnect fuel hose from fuel filter outlet. Use Fuel Pressure Gauge (09268-41045) to "T" fuel injector between fuel filter and fuel pressure regulator. (Scheme 141)and (Scheme 142).
3. Place injector into clean container. Place tube on end of injector to prevent fuel from spilling. Connect Fuel Injector Tester (09842-30070) or trigger box with appropriate resistor to fuel injector. Turn ignition on, with engine off.
4. Connect jumper wire to engine check connector terminals FP and +B to pressurize fuel system. For engine check connector locations see scheme 9 Connector terminals are marked on inside of check connector cover.
5. Trigger injector for 15 seconds. Measure volume and check spray pattern. Test each injector 2-3 times. Replace injector if volume is not as specified. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-21027-S22779102222001010300000) table.
6. Disconnect injector trigger. Fuel leakage from end of injector should be one drop or less in one minute. Replace injector if leakage is more than specified.

FUEL INJECTOR VOLUME SPECIFICATIONS

Scheme 141

Scheme 142

Fuel Pressure-Up System

1. Ensure coolant temperature sensor, air temperature sensor (in airflow meter) and circuits are operating correctly. See «ENGINE SENSORS & SWITCHES»(ref-21027-S42283062132001010300000).
2. Fuel pressure-up system is controlled by ECU through a vacuum switching valve. The vacuum switching valve is fed current through the EFI main relay when the ignition is turned on. ECU controls the ground circuit. ECU will activate vacuum switching valve for 90-180 seconds when restarting engine at normal operating temperature.
3. Vacuum switching valve is located on lower side of intake manifold runners. Remove vacuum switching valve from vehicle. Check for continuity across valve wiring terminals. Resistance should be about 33-39 ohms at room temperature. There should be no continuity between each terminal and body of valve. To check operation (Scheme 143)

Scheme 143

Deceleration Fuel-Cut System

1. Connect a tachometer to engine (to monitor needle fluctuations). See appropriate ADJUSTMENTS article for tachometer attaching points. Start engine and warm to operating temperature. Ensure A/C and other accessories are off.
2. Unplug throttle position sensor connector from throttle position sensor. Short terminals IDL and E1 (or E2) on wire side of connector. (Scheme 144)and (Scheme 145).
3. Gradually raise engine RPM. Fuel-cut operation can be checked by noting the fluctuation of tachometer needle. Fluctuation indicates fuel-cut system is being turned on and off. (Scheme 146) Check that fuel-cut points and fuel return points are within specifications. See «DECELERATION FUEL-CUT & FUEL RETURN RPM»(ref-21027-S20491633892001010300000) table.

DECELERATION FUEL-CUT & FUEL RETURN RPM

Scheme 144

Scheme 145

Scheme 146

Scheme 147

Scheme 148

1. Disconnect negative battery cable. Disconnect cold start injector wiring harness connector. Check resistance between terminals of injector. Replace injector if defective. Resistance should be 2-4 Ohms. If resistance is okay, relieve fuel system pressure.
2. Remove cold start injector from vehicle. Install fuel hose to injector. Install system Union Adapters (9268-41045) to delivery pipe and cold start injector. Connect fuel hose to union adapters. (Scheme 149) Connect Jumper Harness (9842-30050) to cold start injector.
3. Place container under cold start injector. Connect jumper wire to engine check connector terminals FP and B+ to pressurize fuel system. For engine check connector location (Scheme 147)or (Scheme 148). Turn ignition on, with engine off. CAUTION: Perform cold start injector connector test in shortest possible time.
4. Connect probes of Fuel Injection Tester (09842-30070) to battery. Connect other end of tester to cold start injector. (Scheme 149) Ensure fuel spray is an even cone shape.
5. Disconnect fuel injector tester harness and observe cold start injector. Maximum leakage should be one drop per minute with fuel pressure applied. Clean or replace cold start injector if defective.

Scheme 149

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

For test procedures, see ENGINE SENSORS & SWITCHES .

2.0L

1. Warm engine to normal operating temperature. Ensure idle speed is correct. Apply parking brake, block drive wheels and place transaxle in Neutral.
2. Install jumper wire between terminals "TE1" (or "T") and "E1" of check connector located near left shock tower. (Scheme 150) Engine RPM should increase to 1000-1300 RPM for 5 seconds and then return to idle.
3. If engine RPM was not within specification, check Idle Speed Control (ISC) valve, wiring to ECU, and ECU grounds. If engine RPM was within specification, remove jumper wire. Turn ignition off.
4. Unplug ISC valve connector on bottom of throttle body. Using ohmmeter, measure resistance between terminals "B+" and "ISC1", and between "ISC2" and "B+". (Scheme 151) Replace valve if resistance is not within 16-17 ohms.

Scheme 150

Scheme 151

2.5L

1. Listen for clicking sound after engine is shut off. If no sound is heard, check ISC valve and wiring.
2. To check wiring circuit, turn engine off. Unplug ISC valve connector. Turn ignition on with engine off. Connect voltmeter between "B1" and "B2" terminals of wiring harness connector. (Scheme 152) Battery voltage should be present. If not, check wiring between ISC valve and EFI main relay.
3. To check ISC valve, turn ignition off. Unplug ISC valve connector. Measure resistance between ISC valve terminals. (Scheme 152) See «ISC VALVE RESISTANCE SPECIFICATIONS»(ref-21027-S15659732492001010300000) table. Replace ISC valve if resistance is not as specified. ISC VALVE RESISTANCE SPECIFICATIONS Terminals Ohms "B1" to "S1" or "S3" 10-30 "B2" to "S2" or "S" 10-30 NOTE: Before removing ISC valve, drain coolant from cooling system. Remove both coolant by-pass hoses. On Supra Turbo only, ensure check valve and seal washer are installed in air intake chamber.
4. To check valve operation, remove ISC valve from vehicle. Apply battery voltage to terminal "B1" and terminal "B2". (Scheme 152) Repeatedly ground terminals "S1", "S2", "S3" and "S" in sequence. Valve should close. Remove ground wires.
5. Apply battery voltage to terminals B1 and B2. Repeatedly ground terminals "S", "S3", "S2" and "S1" in sequence. Valve should move toward open position. Replace valve if operation is not as specified.

Scheme 152

IGNITION SYSTEM

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

KNOCK SENSOR

Probable causes of knock sensor problems include the following

1. Open or short in knock sensor circuit.
2. Knock sensor (looseness etc.).
3. Knock control in ECU is faulty.

Knock sensor problems can also set fault codes 52 and 53. For code charts, see TESTS W/ CODES article.

EGR Vacuum Modulator

1. EGR vacuum modulator is a 3-port type. Disconnect all hoses. Block ports "P" and "R". Apply air pressure to port "Q". (Scheme 153) Air should pass through the air filter side of modulator freely.
2. Operate engine at specified 2500 RPM on 2.0L or 3500 RPM on 2.5L. Repeat test procedures in step 1. Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt. Reconnect vacuum hoses to proper locations.

Scheme 153

Bimetallic Vacuum Switching Valve (BVSV) (2.0L)

1. Drain cooling system and remove BVSV. (Scheme 154) Cool BVSV to 113°F (45°C) using cool water. Apply air to the lower port. Air should pass through air filter located on top of valve assembly.
2. Heat BVSV valve to 151°F (66°C). Apply air to the lower port. Air should pass through from the upper port but not through the air filter. Replace assembly if defective.

Scheme 154

Bimetallic Vacuum Switching Valve (BVSV) (2.5L)

1. Drain cooling system and remove BVSV. (Scheme 155) Using cool water, cool BVSV to less than 104°F (40°C). Apply air through top port of valve. Air should NOT pass through bottom port.
2. Heat BVSV valve to greater than 129°F (54°C). Apply air in top port. Air should pass through lower port. Replace assembly if defective. If BVSV does not function as described, replace valve.

Scheme 155

FUEL EVAPORATION

Note. see scheme 34and see scheme 35 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.

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. On all models, 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.

Restrictor

Remove hoses from restrictor and remove restrictor from vehicle. Blow air through both sides to ensure there is no blockage. Replace restrictor if airflow is blocked in either direction.

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

Positive Crankcase Ventilation (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 (2.5L)

1. Engine must be at normal operating temperature. Check idle speed and adjust if necessary. Remove cap, filter and separator from dashpot. (Scheme 156)
2. Start engine. Maintain engine speed at 2500 RPM. Plug Vacuum Transmitting Valve (VTV) hole with your finger. (Scheme 156)
3. Release throttle. Dashpot should be extended and dashpot setting RPM should be at 2000 RPM with cooling fan off. If idle speed is incorrect, adjust dashpot. (Scheme 157)
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.
5. Install dashpot separator, filter and cap. Install filter with coarser surface facing outward.

Scheme 156

Scheme 157