Engine Controls - System/component Tests: Other Toyota Paseo L40

ENGINE SENSORS & SWITCHES

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

Air Temperature Sensor

1. Ensure ignition is off. Disconnect electrical connector from air temperature sensor. Air temperature sensor is located in air intake, near air filter.
2. Remove air temperature sensor. Place threaded end of air temperature sensor and thermometer in container of water. Attach ohmmeter between air temperature sensor electrical terminals.
3. Heat water and note that resistance is within specification in relation to temperature. (Scheme 44) Replace air temperature sensor if defective.

Scheme 44

Coolant Temperature Sensor (CTS)

1. Ensure ignition is off. Disconnect electrical connector from CTS. CTS is located in engine coolant passage near cylinder head or thermostat housing. To verify wire colors for proper identification, see appropriate wiring diagram in WIRING DIAGRAMS article. NOTE: The CTS may be also identified using appropriate illustration in THEORY/OPERATION article.
2. Using ohmmeter, check resistance between CTS electrical terminals. Resistance should be within specification at designated temperature. (Scheme 45) Replace CTS if resistance is not within specification.

Scheme 45

Coolant Temperature Switch (With A/T)

1. Remove coolant temperature switch. Coolant temperature switch is located in engine coolant passage near cylinder head. To verify wire colors for proper identification, see appropriate wiring diagram in WIRING DIAGRAMS article. NOTE: Coolant temperature switch may be also identified using appropriate illustration in THEORY & OPERATION article.
2. Place threaded end of coolant temperature switch and thermometer in container of water. Attach ohmmeter to switch electrical terminal. Heat water and ensure no continuity exists between switch electrical terminal and switch body when water temperature is less than 208°F (98°C).
3. Check that continuity exists between switch electrical terminal and switch body when water temperature is greater than 221°F (105°C). Replace coolant temperature switch if defective.

Note. The EGR gas temperature sensor may be referred to as EGR function sensor.

EGR Gas Temperature Sensor

1. Remove EGR gas temperature sensor from side of EGR valve. Place threaded end of sensor and thermometer in container of water.
2. Attach ohmmeter to electrical terminals. Heat water and note resistance at specified temperature. See «EGR GAS TEMPERATURE SENSOR SPECIFICATIONS»(ref-21199-S02280695032001010300000) table. Replace EGR gas temperature sensor if resistance is not within specification.

EGR GAS TEMPERATURE SENSOR SPECIFICATIONS

Intake Air Temperature Sensor

See AIR TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES .

Manifold Absolute Pressure (MAP) Sensor

See VACUUM SENSOR under ENGINE SENSORS & SWITCHES .

Park/Neutral Switch

Disconnect electrical connector from park/neutral switch at transmission or transaxle. Note terminal identification. (Scheme 46) Using ohmmeter, check for continuity at specified terminals with gearshift in proper positions. See PARK/NEUTRAL SWITCH SPECIFICATIONS table. Replace switch if defective.

PARK/NEUTRAL SWITCH SPECIFICATIONS

Scheme 46

Throttle Position Sensor (TPS)

1. Turn ignition off. Disconnect electrical connector from TPS on throttle body. Note terminal identification. (Scheme 47)
2. Insert specified thickness feeler gauge between throttle stop screw and throttle lever and check resistance or continuity. See appropriate «TPS RESISTANCE SPECIFICATIONS»(ref-21199-S13953557492001010300000) 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 47

TPS RESISTANCE SPECIFICATIONS

Vacuum Sensor

1. Ensure ignition is off. To check vacuum sensor supply voltage, disconnect electrical connector from vacuum sensor. See «VACUUM SENSOR LOCATIONS»(ref-21199-S28783575522001010300000) table. NOTE: Vacuum sensor may also be identified using appropriate illustration in THEORY/OPERATION article. Vacuum sensor has a vacuum hose connected to it and may be identified by wire colors. See appropriate wiring diagram in WIRING DIAGRAMS article. VACUUM SENSOR LOCATIONS Application Location Paseo Center Of Firewall In Engine Compartment
2. Turn ignition on. Using voltmeter, measure voltage between terminals VCC and E2 of electrical connector on wiring harness. (Scheme 48) The VCC and E2 terminals are the 2 outer terminals on all models. Voltage should be within specification. See «VACUUM SENSOR SUPPLY VOLTAGE SPECIFICATIONS»(ref-21199-S25015617382001010300000) table. VACUUM SENSOR SUPPLY VOLTAGE SPECIFICATIONS Application Voltage Paseo 4.00-6.00
3. If supply voltage is not within specification, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If supply voltage is correct, turn ignition off. Reinstall electrical connector on vacuum sensor.
4. 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 Engine Control Module (ECM). (Scheme 49)and (Scheme 50). See «ECM LOCATION»(ref-21199-S27211442452001010300000) table. ECM LOCATION Application Location Paseo Bottom Center Of Dash In Front Of Console
5. Measure and record output voltage under ambient atmospheric pressure. Attach vacuum pump to vacuum sensor.
6. Apply vacuum in specified increments and measure output voltage drop at each increment. See «VACUUM SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS»(ref-21199-S39176355942001010300000) table. Replace vacuum sensor if output voltage drop is not within specification.

VACUUM SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS

Scheme 48

Scheme 49

Scheme 50

Vehicle Speed Sensor

1. Vehicle speed sensor is located on rear of combination meter in instrument cluster. Connect ohmmeter between terminals "A" and "B". Terminals are located near vehicle speed sensor. (Scheme 51)
2. Rotate speedometer cable shaft and note reading. Ohmmeter should deflect from continuity to no continuity 4 times per speedometer cable shaft revolution. Replace vehicle speed sensor or speedometer if reading does not deflect as specified.

Scheme 51

FUEL PUMP ELECTRONIC CONTROL UNIT

See FUEL CONTROL under FUEL SYSTEM.

Circuit Opening Relay

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(ref-21199-S02889687992001010300000) table. Using ohmmeter, check continuity between specified terminals. (Scheme 52)and (Scheme 53).
2. Check circuit opening relay operation by applying battery voltage and ground and checking continuity between specified terminals. (Scheme 52)and (Scheme 53). Replace circuit opening relay if defective.

Note. Circuit opening relay may also be identified using appropriate illustration in THEORY & OPERATION article or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article.

CIRCUIT OPENING RELAY LOCATION

Scheme 52

Scheme 53

EFI MAIN RELAY

Note. The EFI main relay may also be referred to as MFI main relay, SFI main relay or MPI main relay.

1. Ensure ignition is off. Remove EFI main relay. See «EFI MAIN RELAY LOCATION»(ref-21199-S14758749352001010300000) table. Using ohmmeter, check continuity between specified terminals. (Scheme 54)and (Scheme 55).
2. Check EFI main relay operation by applying battery voltage and ground and checking continuity between specified terminals. (Scheme 54)and (Scheme 55). Replace EFI main relay if defective.

Note. The EFI main relay may also be identified using appropriate illustration in THEORY & OPERATION article or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article.

EFI MAIN RELAY LOCATION

Scheme 54

Scheme 55

IGNITION MAIN RELAY

See IGNITION MAIN RELAY under IGNITION SYSTEM.

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING article.

See CIRCUIT OPENING RELAY under RELAYS .

See EFI MAIN RELAY under RELAYS .

Fuel Pump Relay

See FUEL PUMP RELAY under RELAYS .

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»(ref-21199-S11772348802001010300000) table.
2. To check fuel injector spray pattern and volume, remove fuel injector. See N - REMOVE/INSTALL/OHAUL article. Disconnect fuel hose from fuel filter outlet. Use Delivery Hose (09268-41045) to install fuel injector between fuel filter and fuel pressure regulator. (Scheme 56)and (Scheme 57).
3. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage. Install Jumper Wire (SST 09843-18020) between +B and FP terminals of data link connector No. 1. Turn ignition on, with engine off to pressurize fuel system. NOTE: For proper location of data link connector No. 1 and terminal identification, see BASIC DIAGNOSTICS PROCEDURES article. Jumper wire is installed in data link connector No. 1 when checking fuel pump operation and fuel pressure.
4. Connect fuel injector tester to fuel injector for 15 seconds. Use Fuel Injector Tester (09842-30060) for Celica Turbo, MR2 Turbo and Supra Turbo or (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»(ref-21199-S39738877242001010300000) table. NOTE: Ensure difference between fuel injector volume on all fuel injectors is within specification. See FUEL INJECTOR VOLUME SPECIFICATIONS table.
6. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector is one drop or less in specified time. See «FUEL INJECTOR LEAKAGE SPECIFICATIONS»(ref-21199-S25817813202001010300000) table. Replace fuel injector if leakage exceeds specified amount. Turn ignition off and remove test equipment.

FUEL INJECTOR RESISTANCE SPECIFICATIONS

FUEL INJECTOR VOLUME SPECIFICATIONS

FUEL INJECTOR LEAKAGE SPECIFICATIONS

Scheme 56

Scheme 57

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

Fuel Pressure Control System

1. Fuel pressure control Vacuum Switching Valve (VSV) is supplied voltage through EFI main relay.
2. Engine Control Module (ECM) will activate VSV by controlling ground circuit for approximately 90 seconds when restarting engine at normal operating temperature. Locate and remove fuel pressure control VSV. See «FUEL PRESSURE CONTROL VSV LOCATION»(ref-21199-S18881471142001010300000) table. NOTE: Fuel pressure control VSV may also be identified using appropriate illustration in THEORY/OPERATION article or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article. FUEL PRESSURE CONTROL VSV LOCATION Application Location Paseo Near Front Of Valve Cover, On Firewall Side
3. Using ohmmeter, check resistance and for continuity between fuel pressure control VSV electrical terminals. Replace fuel pressure control VSV if no continuity exists or resistance is not within specification. See «FUEL PRESSURE CONTROL VSV RESISTANCE SPECIFICATIONS»(ref-21199-S00712254352001010300000) table.
4. Ensure no continuity exists between each electrical terminal and fuel pressure control VSV body. Replace fuel pressure control VSV if continuity exists between electrical connector and fuel pressure control VSV body.
5. Check fuel pressure control VSV operation by applying air pressure to designated area and checking air passage, and then applying battery voltage and ground and retesting. (Scheme 58) Replace fuel pressure control VSV if defective.

FUEL PRESSURE CONTROL VSV RESISTANCE SPECIFICATIONS

Scheme 58

Fuel Cut System

1. Install tachometer. Ensure tachometer is connected to proper terminals. See IDLE SPEED & MIXTURE in ADJUSTMENTS article. 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. Disconnect electrical connector from throttle position sensor. Install jumper wire between IDL and E2 terminals on wiring harness side. (Scheme 59)
3. Start engine and warm to normal operating temperature. Ensure all accessories are off. Gradually increase engine RPM. Note fluctuation in tachometer reading to indicate fuel cut RPM and fuel return RPM. (Scheme 60)
4. Ensure fuel cut and fuel return RPM are within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(ref-21199-S05834336832001010300000) table. Shut engine off. Disconnect tachometer. Reinstall electrical connector on throttle position sensor.

Scheme 59

Scheme 60

FUEL CUT SYSTEM SPECIFICATIONS

AIR CONTROL VALVE

1. Remove air control valve, located on end of air intake chamber on passenger's side. Air control valve may also be identified using appropriate illustration in THEORY/OPERATION article or wire color. See appropriate wiring diagram in WIRING DIAGRAMS article.
2. Using ohmmeter, check resistance and for continuity between air control valve electrical terminals. Replace air control valve if resistance is not within specification or continuity does not exist. See «AIR CONTROL VALVE RESISTANCE SPECIFICATIONS»(ref-21199-S01942184722001010300000) table. AIR CONTROL VALVE RESISTANCE SPECIFICATIONS Application Ohms Paseo 30-33
3. Ensure no continuity exists between each electrical terminal and air control valve body. Test air control valve by applying air pressure to designated area and checking air passage, and then applying battery voltage and ground and retesting. (Scheme 61) Replace air control valve if defective or continuity exists between electrical terminals and air control valve body.

Scheme 61

AUXILIARY AIR VALVE SYSTEM

Note. Install tachometer when checking auxiliary air valve system. Ensure tachometer is connected to proper terminals. See IDLE SPEED & MIXTURE in ADJUSTMENTS article for tachometer connections.

1. Install tachometer. With engine coolant less than 176°F (80°C), remove air intake hose from throttle body.
2. Start engine. Place finger over air valve port to block airflow. (Scheme 62) Engine speed should decrease noticeably. Remove finger from air valve port.
3. Allow engine to warm to normal operating temperature. Place finger over air valve port to block airflow. Engine speed should not decrease more than 100 RPM for Tercel or 50 RPM for all others.
4. If engine RPM does not respond as indicated, check for vacuum leaks or restricted chamber in auxiliary air valve circuit. If no defects are found, replace auxiliary air valve.

Scheme 62

EXHAUST GAS RECIRCULATION (EGR)

Note. EGR systems contain different components and have different operating parameters depending on application. (Scheme 64)-27. When testing EGR system and components, use proper illustration to determine component location.

EGR Vacuum Modulator

1. Disconnect vacuum hoses from EGR vacuum modulator. Block ports "P" and "R" of EGR vacuum modulator. see scheme 23 NOTE: Ports "P" and "R" are the double ports on side of EGR vacuum modulator. Port "Q" is the single port on side of EGR vacuum modulator.
2. Apply air pressure to port "Q". see scheme 23 Air should pass freely through air filter side of EGR vacuum modulator.
3. Start and operate engine at specified RPM. See «EGR VACUUM MODULATOR TESTING SPECIFICATIONS»(ref-21199-S01245354352001010300000) 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 TESTING SPECIFICATIONS

Note. Bimetallic Vacuum Switching Valve (BVSV) may be referred to as a Thermal Vacuum Valve (TVV). When testing BVSV, use proper illustration to determine component location. (Scheme 64)-27.

EGR Vacuum Switching Valve (VSV)

1. Disconnect electrical connector from EGR VSV. Using ohmmeter, check resistance between EGR VSV electrical terminals.
2. Replace EGR VSV if resistance is not within specification. See «EGR VSV RESISTANCE SPECIFICATIONS»(ref-21199-S39932598812001010300000) table. Check that no continuity exists between each electrical terminal and EGR VSV body. Replace EGR VSV if continuity exists between any electrical terminal and VSV body.
3. Apply air pressure to port "E" (without battery connected). (Scheme 63) Air pressure should not flow through port "F". Connect battery to EGR VSV electrical terminals. (Scheme 65) Apply air pressure to port "E". Air pressure should flow from port "F". Replace EGR VSV if defective.

EGR VSV RESISTANCE SPECIFICATIONS

Scheme 63

Scheme 64

Scheme 65

Scheme 66

FUEL EVAPORATION

Note. Fuel evaporation systems contain different components and have different operating parameters depending on application. (Scheme 67)and (Scheme 68).

Scheme 67

Scheme 68

Note. The Bimetallic Vacuum Switching Valve (BVSV) may be referred to as a Thermal Vacuum Valve (TVV).

Bimetallic Vacuum Switching Valve

1. Drain cooling system. Remove Bimetallic Vacuum Switching Valve (BVSV). BVSV is located in coolant passage and contains 2 vacuum hoses which go to the charcoal canister and throttle body.
2. Use cool water to cool threaded end of BVSV to less than 95°F (35°C). Apply air pressure to top port on BVSV. Ensure BVSV is closed and no air will pass through lower port.
3. Heat water to greater than 129°F (54°C). Apply air pressure to top port on BVSV. Ensure BVSV is open and air passes through lower port. Replace BVSV if defective. Apply thread sealant to threads of BVSV and reinstall. Fill cooling system.

Charcoal Canister

1. Disconnect hoses from charcoal canister. Check for clogged filter and/or stuck check valve by applying low air pressure to port "A". (Scheme 69) Ensure air flows freely from other ports on charcoal canister.
2. Apply low air pressure to port "B". (Scheme 69) Ensure no air flows from any other ports on charcoal canister. Replace charcoal canister if defective.
3. To clean charcoal canister filter, apply 43 psi (3 kg/cm 2 ) air pressure to port "A" while holding port "B" closed. Ensure no activated carbon comes out of charcoal canister. DO NOT attempt to wash out charcoal canister.

Scheme 69

THROTTLE CONTROLS

Note. When testing throttle control systems, tachometer may be required. Ensure tachometer is connected to proper terminals. For tachometer connections, see IDLE SPEED & MIXTURE in ADJUSTMENTS article.

Throttle Opener ( Paseo Calif. & A/T Models, Pickup 3.0L, Supra, Tercel Calif. Models, T100 & 4Runner 3.0L)

1. Warm engine to normal operating temperature. Ensure idle speed is correct. See IDLE SPEED & MIXTURE in ADJUSTMENTS article.
2. Disconnect and plug vacuum hose at throttle opener, located on side of throttle body. Start engine. Maintain engine speed at 2500 RPM. Release throttle and note engine speed. Engine speed should be within specification. See «THROTTLE OPENER SPECIFICATIONS»(ref-21199-S05385323432001010300000) table.
3. Replace throttle body if engine speed is not within specification. Reinstall vacuum hose on throttle opener. Start engine and ensure engine returns to correct idle speed.

Scheme 70

THROTTLE OPENER SPECIFICATIONS

Throttle Opener Vacuum Switching Valve

1. Disconnect hoses and electrical connector from throttle opener Vacuum Switching Valve (VSV).
2. Throttle opener VSV is rear VSV located near front of valve cover. VSV contains a 2-wire electrical connector with a Red/Green and Black/Orange wire. NOTE: Throttle opener VSV may also be identified using appropriate illustration in THEORY/OPERATION article.
3. Use ohmmeter to ensure continuity exists between electrical terminals on VSV and resistance is within specification. See «THROTTLE OPENER VSV RESISTANCE SPECIFICATIONS»(ref-21199-S07533083082001010300000) table. THROTTLE OPENER VSV RESISTANCE SPECIFICATIONS Application Ohms @ 68°F (20°C) Paseo 37-44
4. No continuity exists between each electrical terminal and the body of VSV. Apply air pressure to port "E". Ensure air passes out port "G". Perform STEP 1. (Scheme 71)
5. Connect battery voltage and ground to VSV terminals. Apply air pressure to port "E". Ensure air passes out port "F" and not port "G". Perform STEP 2. (Scheme 71) Replace VSV if defective.

Scheme 71