Engine Controls - System/component Tests: Other Toyota Paseo L50

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

CAMSHAFT POSITION SENSOR

For testing camshaft position sensor, see CAMSHAFT POSITION SENSOR under IGNITION CHECKS (DISTRIBUTORLESS IGNITION SYSTEM) in BASIC TESTING article.

CRANKSHAFT POSITION SENSOR

For testing crankshaft position sensor, see CRANKSHAFT POSITION SENSOR under IGNITION CHECKS (DISTRIBUTORLESS IGNITION SYSTEM) in BASIC TESTING article.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Ensure ignition is off. Disconnect electrical connector from ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-22373-S25633509472001010300000) table. To verify wire colors for proper sensor identification, see appropriate wiring diagram in «WIRING DIAGRAMS»(ref-22375) article. NOTE: The ECT sensor may be also identified using appropriate illustration in «THEORY/OPERATION»(ref-22374) article.
2. Drain cooling system and remove ECT sensor. 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 10) Replace ECT sensor if resistance is not within specification.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION

Scheme 10

HEATED OXYGEN SENSOR

See OXYGEN SENSOR under ENGINE SENSORS & SWITCHES.

INTAKE AIR TEMPERATURE SENSOR

1. Ensure ignition is off. Disconnect electrical connector from intake air temperature sensor. Intake air temperature sensor is located on top cover of air filter housing. NOTE: Intake air temperature sensor may be also identified using appropriate illustration in «THEORY/OPERATION»(ref-22374) article.
2. Remove intake air temperature sensor. Place threaded end of intake air temperature sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on intake air temperature sensor.
3. Heat water and note that resistance is within specification in relation to temperature. (Scheme 10) Replace intake air temperature sensor if resistance is not within specification.

KNOCK SENSOR

Note. Knock sensor may also be referred to as knock sensor No. 1.

1. Knock sensor is located on side of the cylinder block. (Scheme 11) Remove knock sensor from cylinder block before testing. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES in «REMOVE/INSTALL/OVERHAUL»(ref-22380) 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 11

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR

1. Ensure ignition is off. To check MAP sensor supply voltage, disconnect electrical connector from MAP sensor. See «MAP SENSOR LOCATION»(ref-22373-S18212030932001010300000) table. NOTE: MAP sensor may also be identified using appropriate illustration in «THEORY/OPERATION»(ref-22374) article. The MAP sensor has a vacuum hose connected to it and may be identified by wire colors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-22375) article. MAP SENSOR LOCATION Application Location Paseo Passenger's Side Of Engine Compartment, On Firewall, Near Wiper Motor
2. Turn ignition on. Using voltmeter, check MAP sensor supply voltage between terminals E2 and VC or VCC on wiring harness side of electrical connector for MAP sensor. (Scheme 12) The E2 and VC or VCC terminals are the 2 outer terminals on all models. DO NOT use the center terminal.
3. The MAP sensor supply voltage should be 4.5-5.5 volts. If MAP sensor supply voltage is not within specification, check wiring circuit. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-22375) article. If MAP sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on MAP sensor.
4. To check MAP sensor output voltage, turn ignition on. Disconnect vacuum hose from MAP sensor. Connect voltmeter between terminals PIM and E2 on Engine Control Module (ECM). (Scheme 13) See «ECM LOCATION»(ref-22373-S33977166982001010300000) table. See «TERMINAL & WIRE COLOR IDENTIFICATION»(ref-22373-S40486383422001010300000) table. ECM LOCATION Model Location Paseo Behind Glove Box TERMINAL & WIRE COLOR IDENTIFICATION Terminal Wire Color PIM Pink E2 Brown
5. Measure and record output voltage under ambient atmospheric pressure. Attach vacuum pump to MAP sensor.
6. Apply vacuum in specified increments and measure MAP sensor output voltage drop at each increment. See «MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS»(ref-22373-S02696260362001010300000) table. Replace MAP sensor if output voltage drop is not within specification.

MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS

Scheme 12

Scheme 13

OXYGEN SENSOR

1. Two oxygen sensors are used. A non-heated oxygen sensor is located on exhaust manifold. This oxygen sensor is referred to as the No. 1 or front oxygen sensor. Another heated oxygen sensor is located on exhaust pipe behind catalytic converter. This oxygen sensor is referred to as the No. 2 oxygen sensor or the rear oxygen sensor.
2. If problem exists with either oxygen sensor, a diagnostic trouble code will be stored in Engine Control Module (ECM). For diagnostic trouble code diagnosis, see «TESTS W/CODES»(ref-22376) article.
3. To test the heater on No. 2 oxygen sensor, disconnect electrical connector for No. 2 oxygen sensor. Electrical connector for No. 2 oxygen sensor is a Dark Gray 4-pin electrical connector located below passenger's side front seat, behind the carpet, next to side of center console.
4. Using ohmmeter, check resistance between terminals +B and HT. (Scheme 14) Replace oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).

Scheme 14

A/T

If problem exists with Park/Neutral Position (PNP) switch or circuit, a diagnostic trouble Code P1780 will be stored in the Engine Control Module (ECM). For diagnostic trouble code diagnosis, see TESTS W/CODES article.

1. Disconnect electrical connector from Park/Neutral Position (PNP) switch. The PNP switch is mounted on side of transmission/transaxle. Note terminal identification. (Scheme 15)
2. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(ref-22373-S35926567312001010300000) table. If proper continuity does not exist, adjust or replace switch as necessary.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 15

THROTTLE POSITION (TP) SENSOR

1. Ensure ignition is off. Disconnect electrical connector from TP sensor on throttle body. Note terminal identification. (Scheme 16) On A/T models, disconnect throttle cable from linkage before checking TP sensor.
2. On all models, use ohmmeter to check resistance between specified terminals in relation to throttle position. See «TP SENSOR RESISTANCE SPECIFICATIONS»(ref-22373-S20942716072001010300000) table. Replace components as necessary if resistance is not within specification.

TP SENSOR RESISTANCE SPECIFICATIONS

Scheme 16

VAPOR PRESSURE SENSOR

See FUEL EVAPORATION SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS.

VEHICLE SPEED SENSOR

1. Vehicle speed sensor is located on rear of combination meter in instrument cluster. Connect ohmmeter between terminals "A" and "B" on rear of instrument cluster. (Scheme 17)
2. Rotate speedometer cable shaft and note reading. Ohmmeter should deflect from continuity to no continuity 4 times per speedometer cable shaft revolution. Replace speedometer if reading does not deflect as specified.

Scheme 17

CIRCUIT OPENING RELAY

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(ref-22373-S09802812192001010300000) table. (Scheme 18) CIRCUIT OPENING RELAY LOCATION Application Relay Location Paseo Near Top Right Corner Of Fuse/Relay Box Behind Driver's Side Lower Instrument Panel Cover, Near Steering Column
2. To check circuit opening relay continuity, use ohmmeter to check continuity between specified terminals. (Scheme 19)
3. To check circuit opening relay operation, apply battery voltage and ground to relay and use ohmmeter to check continuity between specified terminals. (Scheme 19) Replace circuit opening relay if defective.

Scheme 18

Scheme 19

EFI MAIN RELAY

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

1. Ensure ignition is off. Remove EFI main relay. See «EFI MAIN RELAY LOCATION»(ref-22373-S04795458672001010300000) table. NOTE: The EFI main relay may also be identified using appropriate illustration in «THEORY/OPERATION»(ref-22374) article. EFI MAIN RELAY LOCATION Application Location Paseo In Fuse/Relay Box Near Driver's Side Front Corner Of Engine Compartment, Just In Front Of Strut Tower
2. To check EFI main relay continuity, use ohmmeter to check continuity between specified terminals. (Scheme 20)
3. To check EFI main relay operation, apply battery voltage and ground to relay and use ohmmeter to check continuity between specified terminals. (Scheme 20) Replace EFI main relay if defective.

Scheme 20

See CIRCUIT OPENING RELAY under RELAYS.

See EFI MAIN RELAY under RELAYS.

Fuel Pump Pressure

For fuel pump pressure testing, see BASIC TESTING article.

Fuel Injectors

1. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, check resistance between electrical terminals on fuel injector. Replace fuel injector if resistance is not within specification. See «FUEL INJECTOR RESISTANCE»(ref-22373-S27335870622001010300000) table.
2. To check fuel injector volume, remove fuel injector. See FUEL RAILS & FUEL INJECTORS under FUEL SYSTEM in «REMOVE/INSTALL/OVERHAUL»(ref-22380) article. Disconnect fuel hose from fuel filter and use Delivery Hose (09268-41046) to install fuel injector on fuel filter. (Scheme 21) NOTE: Fuel injector is connected to fuel filter, as fuel pressure regulator is located on the fuel pump in the fuel tank.
3. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage.
4. Use scan tool to operate the fuel pump to pressurize the fuel system. See FUEL PRESSURE under FUEL SYSTEM in «BASIC TESTING»(ref-22371) article. NOTE: Fuel pump may also be operated to pressurize fuel system by applying battery voltage to electrical terminals on fuel pump. For operating of fuel pump, see FUEL PUMP RESISTANCE & OPERATION under «FUEL DELIVERY»(ref-22373-S41776938342001010300000) under FUEL SYSTEM.
5. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 22) Measure fuel injector volume. Test each fuel injector 2-3 times. Replace fuel injector if fuel injector volume is not within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-22373-S20993191352001010300000) table. NOTE: Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-22373-S20993191352001010300000) 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-22373-S01607658702001010300000) table. Replace fuel injector if leakage exceeds specified amount.

FUEL INJECTOR RESISTANCE - Ohms @ 68°F (20°C)

FUEL INJECTOR VOLUME SPECIFICATIONS

FUEL INJECTOR LEAKAGE SPECIFICATIONS

Scheme 21

Scheme 22

Fuel Cut System

1. When testing fuel cut system, engine RPM must be monitored using scan tool. Connect scan tool to data link connector No. 3 for monitoring engine RPM. For connecting of scan tool, see appropriate application under IDLE SPEED & MIXTURE in «ADJUSTMENTS»(ref-22372) article.
2. Start and warm engine to normal operating temperature. Ensure the A/C and all accessories are off. Gradually increase engine RPM to maintain at least specified engine speed. See «FUEL CUT SYSTEM TESTING SPECIFICATIONS»(ref-22373-S37746837242001010300000) table. FUEL CUT SYSTEM TESTING SPECIFICATIONS Application Engine RPM Paseo 2500
3. 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).
4. Ensure fuel return RPM is within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(ref-22373-S34836752012001010300000) table. Shut engine off. Remove test equipment.

FUEL CUT SYSTEM SPECIFICATIONS (1)

IDLE AIR CONTROL (IAC) VALVE

1. Warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in «ADJUSTMENTS»(ref-22372) article.
2. Apply parking brake and place transmission/transaxle in Neutral. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 23) Start engine and note RPM. NOTE: Data link connector No. 1 is located in engine compartment. NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 2) to step 4). No test procedures have been omitted.
3. Engine RPM should increase to specified RPM for 5 seconds, and then return to idle. See «IAC VALVE ENGINE SPEED TESTING SPECIFICATIONS»(ref-22373-S33222634922001010300000) table. IAC VALVE ENGINE SPEED TESTING SPECIFICATIONS Application Engine RPM Paseo 900-1300
4. If engine RPM is not as specified, test IAC valve resistance and operation. If engine RPM is within specification, remove jumper wire. Turn ignition off.
5. To test IAC valve resistance, ensure ignition is off. Disconnect electrical connector from IAC valve. IAC valve is located on lower area of throttle body. Using ohmmeter, check resistance between terminal +B and each remaining terminal. (Scheme 24)
6. Replace IAC valve if resistance is not within specification. See «IAC VALVE RESISTANCE SPECIFICATIONS»(ref-22373-S32775457622001010300000) table. IAC VALVE RESISTANCE SPECIFICATIONS Application Ohms Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 (1) Cold is with temperature of 14-122°F (-10 - 50°C). (2) Hot is with temperature of 122-212°F (50-100°C).
7. To test IAC valve operation, remove IAC valve from throttle body. Connect positive battery terminal to +B terminal on IAC valve. (Scheme 25) Connect negative battery cable to proper terminal and ensure valve opens and closes. (Scheme 25) Replace IAC valve if defective.
8. 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-22373-S33977166982001010300000) table. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-22375) article.

ECM LOCATION

Scheme 23

Scheme 24

Scheme 25

IGNITION SYSTEM

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

See KNOCK SENSOR under ENGINE SENSORS & SWITCHES.

FUEL EVAPORATION SYSTEM

Note. Fuel evaporation systems contain different components depending on application. see scheme 18 When testing fuel evaporation system components, it may be necessary to use proper illustration to determine component location.

Charcoal Canister

1. Remove charcoal canister. Install plug on port "E" at top of charcoal canister. (Scheme 26)
2. Check for clogged filter and/or stuck check valve and diaphragm by applying light air pressure to port "A" while holding port "B" closed. (Scheme 26) Ensure air flows freely from port "D".
3. Apply light air pressure to port "A" while holding ports "B" and "D" closed. (Scheme 26) Ensure no air flows from port "C".
4. Using vacuum pump, apply light vacuum to port "B". Ensure vacuum does not decrease when port "C" is closed, and that vacuum decreases when port "C" is opened.
5. While holding port "C" closed, use vacuum pump to apply light vacuum to port "A". Ensure air flows into port "B". Replace charcoal canister if defective.

Scheme 26

EVAP Vacuum Switching Valve

1. Remove EVAP Vacuum Switching Valve (VSV). See «EVAP VSV LOCATION»(ref-22373-S24262494862001010300000) table. see scheme 18 EVAP VSV LOCATION Application Location Paseo Bolted To Side Of Air Intake, Near Air Filter NOTE: EVAP VSV may also be identified by wire colors. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-22375) article.
2. Using ohmmeter, ensure continuity exists between electrical terminals on EVAP VSV and resistance is 30-34 ohms at 68°F (20°C). Ensure no continuity exists between each electrical terminal and the body of the EVAP VSV. Replace EVAP VSV if continuity exists between electrical terminal and body of EVAP VSV.
3. To test EVAP VSV operation, apply air pressure to port "E". Ensure air does not flow from port "F". Perform STEP 1. (Scheme 27)
4. 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 27) Replace EVAP VSV if defective.

Scheme 27

Testing information is not available from manufacturer at time of publication.

Vapor Pressure Sensor Vacuum Switching Valve

1. Remove vapor pressure sensor Vacuum Switching Valve (VSV). see scheme 18 See «VAPOR PRESSURE SENSOR VSV LOCATION»(ref-22373-S17473580432001010300000) table. VAPOR PRESSURE SENSOR VSV LOCATION Application Location Paseo On Bracket, Near Passenger's Side Strut Tower & Contains Brown 2-Pin Electrical Connector
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-22373-S41268414162001010300000) 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) Paseo 33-39
3. Ensure no continuity exists between each electrical terminal and the 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 28)
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 28) Replace vapor pressure sensor VSV if defective.

Scheme 28

POSITIVE CRANKCASE VENTILATION (PCV)

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