Engine Controls - Basic Diagnostic Procedures - 4-CYLINDER: Other Toyota Prius I рестайлинг

SERVICE PRECAUTIONS

Note. On MR2, article applies to 2000 and 2001 models. On all other models, article applies only to 2001 models.

Note. Before performing basic diagnostic procedures, check for any related Technical Service Bulletins (TSBs).

PRIUS

The following service precautions must be followed

Scheme 21

1. Ensure ignition is off and ignition key is removed from ignition before performing any inspection or service procedure in engine compartment, as engine may automatically start and shut off when ignition is on and READY light is illuminated. READY light is displayed just above the shift lever position indicator on instrument cluster at center of instrument panel.
2. Read all service and warning labels in engine compartment before performing any procedures in engine compartment.
3. All high-voltage wiring harness connectors contain Orange connectors. DO NOT touch any wiring harness that contains Orange connectors.
4. High-voltage battery and other high-voltage components may be identified by HIGH VOLTAGE caution labels on them. DO NOT touch these components.
5. If necessary to inspect or service high-voltage system, ensure ignition is off. Remove service plug and wait at least 5 minutes to ensure high voltage is fully discharged before touching any high-voltage wiring harness, connectors or components. Service plug is located on service plug assembly at driver's side front corner of trunk compartment, near high-voltage battery. (Scheme 21) Ensure service plug is stored in a location in which no one may install service plug while technician is working on the vehicle.
6. If necessary to touch any high-voltage wiring harness, connectors or components, ensure service plug is removed and battery voltage or less exists at electrical connector. Use Toyota insulated gloves when touching any high-voltage wiring harness, connectors or components. Ensure insulated gloves are dry and in good condition Ensure that no holes exist by applying air to insulated glove before touching any high-voltage wiring harness, connectors or components.
7. DO NOT wear any metal objects while working on vehicle which may accidently drop and cause a short circuit.
8. If any high-voltage wiring harness connector is disconnected, ensure terminal on wiring harness connector is wrapped with tape to prevent wiring harness connector from contacting any surface.
9. If servicing high-voltage system, place sign on roof of vehicle to indicate to other technicians that high-voltage system is being serviced.

Compression (Camry CNG & Gasoline Models, Camry Solara, Celica, Corolla & ECHO)

Warm engine to normal operating temperature before checking the compression. Ensure battery is fully charged. Disconnect electrical connector(s) at ignition coil(s). Remove ignition coils (if necessary) and spark plugs. Check engine mechanical condition with a compression gauge, vacuum gauge, or engine analyzer with throttle fully open. See engine analyzer manual for specific instructions. See COMPRESSION SPECIFICATIONS table. Install and tighten spark plugs to 13 ft. lbs. (18 N.m).

Compression (Highlander)

Warm engine to normal operating temperature before checking the compression. Ensure battery is fully charged. Disconnect electrical connectors at fuel injectors and ignition coils. Remove ignition coils and spark plugs. Check engine mechanical condition with a compression gauge, vacuum gauge, or engine analyzer with throttle fully open. See engine analyzer manual for specific instructions. See COMPRESSION SPECIFICATIONS table. Install and tighten spark plugs to 14 ft. lbs. (19 N.m).

Compression (MR2)

Warm engine to normal operating temperature before checking the compression. Ensure battery is fully charged. Disconnect electrical connectors at ignition coils. Remove ignition coils and spark plugs. Check engine mechanical condition with a compression gauge, vacuum gauge, or engine analyzer with throttle fully open. See engine analyzer manual for specific instructions. See COMPRESSION SPECIFICATIONS table. Install and tighten spark plugs to 19 ft. lbs. (26 N.m).

Compression (Prius)

1. Manufacturer states procedure using Toyota hand-held tester. Warm engine to normal operating temperature. Shut engine off. Remove air cleaner assembly. Disconnect electrical connectors at ignition coils. Remove ignition coils and spark plugs.
2. Connect Toyota hand-held tester to data link connector No. 3. see scheme 9 Select CRANKING MODE on Toyota hand-held tester using hand-held tester instructions.
3. Connect compression gauge. Crank the engine and note the compression. While in the CRANKING MODE, cranking speed is automatically set at 250 RPM and throttle is automatically opened to fully open position. Read compression in a short a time as possible. See «COMPRESSION SPECIFICATIONS»(ref-11449-S10527596762000111300000) table. Remove scan tool. Install and tighten spark plugs to 13 ft. lbs. (18 N.m).

Compression (RAV4)

Warm engine to normal operating temperature before checking the compression. Ensure battery is fully charged. Disconnect electrical connectors at ignition coils. Remove ignition coils and spark plugs. Check engine mechanical condition with a compression gauge, vacuum gauge, or engine analyzer with throttle fully open. See engine analyzer manual for specific instructions. See COMPRESSION SPECIFICATIONS table. Install and tighten spark plugs to 14 ft. lbs. (19 N.m).

Compression (Tacoma)

1. Warm engine to normal operating temperature before checking the compression. Remove intake air connector for access to spark plugs. Intake air connector fits between air cleaner hose and throttle body.
2. Disconnect electrical connectors at ignition coils. Remove ignition coils and spark plugs. Check engine mechanical condition with a compression gauge, vacuum gauge, or engine analyzer with throttle fully open. See engine analyzer manual for specific instructions. See «COMPRESSION SPECIFICATIONS»(ref-11449-S10527596762000111300000) table. Install and tighten spark plugs to 15 ft. lbs. (20 N.m).

COMPRESSION SPECIFICATIONS

FUEL SYSTEMS

Note. On all models except Camry CNG models, basic diagnosis of fuel system should begin by checking fuel pump operation and fuel pressure.

Note. On Camry CNG models, fuel pump is not used and information is not available from manufacturer for checking fuel pressure. For testing of fuel system components, see FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.

FUEL SYSTEM PRESSURE RELEASE

Note. On Camry CNG models, 2 different fuel system pressure release procedures exist. Procedure using fuel manual shutoff valve releases fuel pressure in fuel system components and fuel lines from fuel manual shutoff valve forward. Procedure for disconnecting fuel tank fuel shutoff valve and fuel tank fuel temperature sensor releases fuel pressure in fuel system for servicing of fuel tank and fuel lines between fuel tank and fuel manual shutoff valve.

Camry CNG Models

Procedure Using Fuel Manual Shutoff Valve

Scheme 22

1. Rotate handle on fuel manual shutoff valve to CLOSED position. Fuel manual shutoff valve is located near driver's side rear tire, underneath the vehicle, near fuel lines just below fuel tank behind the rear seat. (Scheme 22)
2. Start engine and allow engine to idle until engine stalls. Ensure fuel gauge indicates EMPTY. If fuel gauge does not indicate EMPTY, restart engine and allow engine to idle again until engine stalls. If engine will not start, crank engine for a few seconds to release any residual fuel pressure. Turn ignition off. Wait at least 5 seconds after turning ignition off and then disconnect negative battery cable. Fuel pressure should be released from the fuel lines and fuel system components may be serviced.

Procedure For Disconnecting Fuel Tank Fuel Shutoff Valve & Fuel Tank Fuel Temperature Sensor

Scheme 23

1. Remove rear seat back and rear seat cushion for access to electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor. Electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor is located near driver's side end of fuel tank behind the rear seat. (Scheme 23) Disconnect electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor.
2. Start engine and allow engine to idle until engine stalls. Ensure fuel gauge indicates EMPTY. If fuel gauge does not indicate EMPTY, restart engine and allow engine to idle again until engine stalls. Turn ignition off. Disconnect negative battery cable. Fuel pressure should be released from the fuel lines and fuel system components may be serviced. Use care when disconnecting fuel tank filler pipe, as some fuel pressure may still exist.

Camry Gasoline Models, Camry Solara, Celica, Corolla, ECHO, Highlander, MR2, Prius, RAV4 & Tacoma

1. On all models, disconnect electrical connector for fuel pump. See «FUEL PUMP ELECTRICAL CONNECTOR LOCATION»(ref-11449-S38162569842000111300000) table. This is electrical connector for fuel pump and fuel gauge sending unit. Electric fuel pump is located in the fuel tank. FUEL PUMP ELECTRICAL CONNECTOR LOCATION Application Connector Location Camry Gasoline Models, Camry Solara, Celica, Corolla, ECHO & Prius Under Cover Plate, Below Rear Seat Cushion Highlander Under Cover Plate, Below Driver's Side & Passenger's Side Rear Seats MR2 Under Cover Plate, Below Luggage Compartment Boxes Behind The Seats RAV4 Under Cover Plate, Below Driver's Side Rear Seat Tacoma On Top Of Fuel Tank, At Fuel Pump
2. Start engine and allow engine to idle until engine stalls. Turn ignition off. Disconnect negative battery cable.
3. Place suitable container under fuel line connection. Cover fuel line connection with shop towel. Slowly loosen or disconnect fuel line connection, allowing fuel pressure to be released. Once fuel pressure is released, fuel system components may be serviced.

Information for checking fuel pressure is not available from manufacturer. Only fuel pressure specification is available. Fuel pressure between fuel tank and fuel pressure regulator should be 3555 psi (250 kg/cm 2 ), and fuel pressure between fuel pressure regulator and fuel injector should be 114 psi (8.0 kg/cm 2 ).

Scheme 24

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-11449-S37244089302000111300000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel filter. (Scheme 24) Cover union bolt at fuel filter with shop towel. Remove union bolt with gaskets, and disconnect fuel inlet hose from fuel filter.
3. Install fuel pressure gauge from Fuel Pressure Gauge Set (SST 09268-45014) with fuel inlet hose, gaskets and union bolt on fuel filter. (Scheme 24) Tighten union bolt to 21 ft. lbs. (29 N.m).
4. Reconnect negative battery cable. Connect Toyota hand-held tester to data link connector No. 3. see scheme 2and see scheme 3.. Turn ignition on. DO NOT start engine.
5. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump and note fuel pressure. If hand-held tester is not available, fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 12 Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
6. If fuel pressure is within specification, go to next step. If fuel pressure exceeds specification, replace fuel pressure regulator mounted on fuel pump in the fuel tank. See FUEL PRESSURE REGULATOR under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. If fuel pressure is less than specified, check for leaking fuel hoses or connections, restricted fuel filter, defective fuel pump or defective fuel pressure regulator.
7. Turn ignition off. Remove hand-held tester from data link connector No. 3. Start engine and allow engine to idle. Note fuel pressure with engine idling. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
8. Shut engine off and note fuel pressure. Fuel pressure should remain at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure is within specification and holds as specified, go to next step. If fuel pressure is not within specification or does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
9. Release fuel pressure. Disconnect negative battery cable. Remove fuel pressure gauge. Using NEW gaskets, reinstall fuel inlet hose on fuel filter. Tighten union bolt to 21 ft. lbs. (29 N.m). Install negative battery cable. Check for fuel leaks by activating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-11449-S37244089302000111300000). Disconnect negative battery cable.
2. Purchase appropriate fuel pipe from parts department. See «FUEL PIPE IDENTIFICATION»(ref-11449-S30971502442000111300000) table. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 25)and (Scheme 26). FUEL PIPE IDENTIFICATION Application Fuel Pipe Part No. Celica 1.8L 1ZZ-FE 23901-22100 1.8L 2ZZ-GE 23271-88600 Corolla 23901-22010 ECHO 23901-21020 Or 23901-22010 MR2 23901-22070
3. Remove fuel pipe clamp from end of fuel pipe at end of fuel rail. Perform STEP 1 in illustration. (Scheme 27)- (Scheme 30). Ensure area around fuel pipe and disconnect fitting is clean.
4. Depress both sides of retainer and pull fuel pipe with disconnect fitting from fuel pipe fitting. Perform STEP 2 in illustration. (Scheme 27)- (Scheme 30).
5. Install Adapter (SST 09268-41250) and hose with fuel pressure gauge from Fuel Pressure Gauge Set (SST 09268-45014) with fuel pipe connector between fuel pipe and fuel pipe fitting. (Scheme 31) Ensure hose, fuel pipe and fuel pipe connector are properly connected.
6. Install negative battery cable. Connect Toyota hand-held tester to data link connector No. 3. see scheme 4, see scheme 5, see scheme 6 and see scheme 8. Turn ignition on. DO NOT start engine.
7. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump and note fuel pressure. If hand-held tester is not available, fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 13, see scheme 14, see scheme 15 and see scheme 17. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
8. If fuel pressure is within specification, go to next step. If fuel pressure exceeds specification, replace fuel pressure regulator mounted on fuel pump in the fuel tank. See FUEL PRESSURE REGULATOR under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. If fuel pressure is less than specified, check for leaking fuel hoses or connections, restricted fuel filter, defective fuel pump or defective fuel pressure regulator.
9. Turn ignition off. Remove hand-held tester from data link connector No. 3. Start engine and allow engine to idle. Note fuel pressure with engine idling. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
10. Shut engine off and note fuel pressure. Fuel pressure should remain at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure is within specification and holds as specified, go to next step. If fuel pressure is not within specification or does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
11. Release fuel pressure. Disconnect negative battery cable. Remove adapter, hose, fuel pressure gauge and fuel pipe connector.
12. Apply light coat of engine oil on tip of fuel pipe fitting to allow for ease of disconnect fitting and fuel pipe installation. Using NEW retainer, install fuel pipe on fuel pipe fitting until "click" sound is heard. DO NOT reuse old retainer. Pull on fuel pipe to ensure fuel pipe is properly locked on fuel pipe fitting.
13. Reinstall fuel pipe clamp. Install negative battery cable. Check for fuel leaks by activating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

Scheme 32

Scheme 33

Scheme 34

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-11449-S37244089302000111300000). Disconnect negative battery cable.
2. Purchase fuel pipe part No. 23901-28070 for Highlander or 23901-22110 for RAV4 from parts department. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 26)
3. Remove fuel pipe clamp from end of fuel pipe at fuel pipe fitting. (Scheme 32)and (Scheme 33). Ensure area around fuel pipe and disconnect fitting is clean.
4. Depress both tabs and pull fuel pipe with disconnect fitting from fuel pipe fitting. (Scheme 32)and (Scheme 33). Install Adapter (SST 09268-41250) and hose with fuel pressure gauge from Fuel Pressure Gauge Set (SST 09268-45014) with fuel pipe connector between fuel pipe and fuel pipe fitting. (Scheme 31)and (Scheme 34). Ensure hose, fuel pipe and fuel pipe connector are properly connected. Install fuel pipe clamp.
5. Install negative battery cable. Connect Toyota hand-held tester to data link connector No. 3. see scheme 7and see scheme 10. Turn ignition on. DO NOT start engine.
6. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump and note fuel pressure. If hand-held tester is not available, fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 16and see scheme 19. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
7. If fuel pressure is within specification, go to next step. If fuel pressure exceeds specification, replace fuel pressure regulator mounted on fuel pump in the fuel tank. See FUEL PRESSURE REGULATOR under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. If fuel pressure is less than specified, check for leaking fuel hoses or connections, restricted fuel filter, defective fuel pump or defective fuel pressure regulator.
8. Turn ignition off. Remove hand-held tester from data link connector No. 3. Start engine and allow engine to idle. Note fuel pressure with engine idling. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
9. Shut engine off and note fuel pressure. Fuel pressure should remain at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure is within specification and holds as specified, go to next step. If fuel pressure is not within specification or does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
10. Release fuel pressure. Disconnect negative battery cable. Remove adapter, hose, fuel pressure gauge and fuel pipe connector.
11. Install fuel pipe on fuel pipe fitting. Pull on fuel pipe to ensure fuel pipe is properly locked on fuel pipe fitting. Reinstall fuel pipe clamp. Install negative battery cable. Check for fuel leaks by activating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

Scheme 35

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-11449-S37244089302000111300000). Disconnect negative battery cable.
2. Purchase fuel pipe Part No. 23901-21020 from parts department. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 26)
3. Ensure area around fuel pipe at end of fuel rail and disconnect fitting is clean. (Scheme 35)
4. Depress both sides of retainer and pull fuel pipe with disconnect fitting from fuel pipe fitting. (Scheme 35)
5. Install Adapter (SST 09268-41250) and hose with fuel pressure gauge from Fuel Pressure Gauge Set (SST 09268-45014) with fuel pipe connector between fuel pipe and fuel pipe fitting. (Scheme 31) Ensure hose, fuel pipe and fuel pipe connector are properly connected.
6. Install negative battery cable. Connect Toyota hand-held tester to data link connector No. 3. see scheme 9 Turn ignition on. DO NOT start engine.
7. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump and note fuel pressure. If hand-held tester is not available, fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 18 Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
8. If fuel pressure is within specification, go to next step. If fuel pressure exceeds specification, fuel pressure regulator is defective. Fuel pressure regulator is mounted on fuel pump in the fuel tank. It may be necessary to replace fuel pressure regulator, fuel pump and fuel tank as an assembly. Consult parts department for parts availability. If fuel pressure is less than specified, check for leaking fuel hoses or connections or defective fuel pump.
9. Turn ignition off. Remove hand-held tester from data link connector No. 3. Start engine and allow engine to idle. Note fuel pressure with engine idling. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
10. Shut engine off and note fuel pressure. Fuel pressure should remain at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure is within specification and holds as specified, go to next step. If fuel pressure is not within specification or does not hold as specified, check for defective fuel pump or defective fuel injector.
11. Release fuel pressure. Disconnect negative battery cable. Remove adapter, hose, fuel pressure gauge and fuel pipe connector.
12. Apply light coat of engine oil on tip of fuel pipe fitting to allow for ease of disconnect fitting and fuel pipe installation. Using NEW retainer, install fuel pipe on fuel pipe fitting until "click" sound is heard. DO NOT reuse old retainer. Pull on fuel pipe to ensure fuel pipe is properly locked on fuel pipe fitting.
13. Install negative battery cable. Check for fuel leaks by activating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

Scheme 36

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-11449-S37244089302000111300000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel rail. (Scheme 36) Fuel pressure gauge is installed at firewall end of fuel rail, between fuel rail and fuel inlet pipe. Cover union bolt at fuel rail with shop towel. Remove union bolt with gaskets, and disconnect fuel inlet pipe from fuel rail.
3. Install fuel pressure gauge from Fuel Pressure Gauge Set (SST 09268-45012) with gaskets, fuel inlet pipe and union bolt on fuel rail. (Scheme 36) Tighten union bolt to 21 ft. lbs. (29 N.m).
4. Reconnect negative battery cable. Connect Toyota hand-held tester to data link connector No. 3. see scheme 11 Turn ignition on. DO NOT start engine.
5. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump and note fuel pressure. If hand-held tester is not available, fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 20 Fuel pressure should be 38-44 psi (2.7-3.1 kg/cm 2 ).
6. If fuel pressure is within specification, go to next step. If fuel pressure exceeds specification, replace fuel pressure regulator mounted on fuel rail. See FUEL PRESSURE REGULATOR under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. If fuel pressure is less than specified, check for leaking fuel hoses or connections, restricted fuel filter, defective fuel pump or defective fuel pressure regulator.
7. Turn ignition off. Remove hand-held tester from data link connector No. 3. Start engine and allow engine to idle. Note fuel pressure with engine idling. Fuel pressure should be 31-37 psi (2.2-2.6 kg/cm 2 ). If fuel pressure is within specification, go to next step. If fuel pressure is not within specification, check for defective vacuum hose or fuel pressure regulator.
8. Shut engine off and note fuel pressure. Fuel pressure should remain at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure is within specification and holds as specified, go to next step. If fuel pressure is not within specification or does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
9. Release fuel pressure. Disconnect negative battery cable. Remove fuel pressure gauge. Using NEW gaskets, reinstall fuel inlet pipe on fuel rail. Tighten union bolt to 21 ft. lbs. (29 N.m). Install negative battery cable. Check for fuel leaks by activating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

FUEL PUMP CONTROL CIRCUIT

Note. For information on testing relays and fuel system components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. Circuit opening relay may also be identified by appropriate illustration in SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For complete wiring circuit of electrical components on a specific model, see WIRING DIAGRAMS article.

Note. For additional testing information for fuel pump control circuit, see FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.

Circuit Opening Relay (Camry CNG Models)

Circuit opening relay controls fuel supply circuit. When EFI main relay is energized, EFI main relay provides battery voltage to both sides of circuit opening relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel tank fuel shutoff valve and fuel pressure regulator fuel shutoff valve. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

Circuit Opening Relay (Camry Gasoline Models, Camry Solara & Highlander)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to one side of circuit opening relay. When ignition is turned on, voltage is supplied through IGN fuse to other side of circuit opening relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

Circuit Opening Relay (Celica, ECHO & Prius)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to both sides of circuit opening relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

Circuit Opening Relay (Corolla)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to both sides of circuit opening relay. EFI main relay may also be referred to as EFI relay or F-HTR relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

Circuit Opening Relay (MR2)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to one side of circuit opening relay. When ignition is turned on, voltage is supplied from ignition switch to other side of circuit opening relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

Circuit Opening Relay (RAV4)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to one side of circuit opening relay. When ignition is turned on, voltage is supplied to other side of circuit opening relay from IG2 fuse. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

Circuit Opening Relay (Tacoma)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to both sides of circuit opening relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION table.

CIRCUIT OPENING RELAY LOCATION (1)

EFI Main Relay (Camry CNG Models)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, +B terminal of ECM, data link connector No. 1 and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Camry Gasoline Models & Camry Solara)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized when ignition is turned on by voltage supplied through IGN fuse to EFI main relay on vehicles not equipped with engine immobilizer system, or by MREL terminal of Engine Control Module (ECM) on vehicles equipped with engine immobilizer system. When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, +B terminal of ECM, data link connector No. 1 and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Celica)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, EFI No. 1 and 2 fuses, +B terminal of ECM and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Corolla)

EFI main relay may also be referred to as EFI relay or F-HTR relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI fuse may also be referred to as F-HTR fuse. When ignition is turned on, voltage is supplied through IGN fuse to other side of EFI main relay. EFI main relay is then energized and provides battery voltage to circuit opening relay, data link connector No. 1, +B terminal of Engine Control Module (ECM) and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (ECHO)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. When ignition is turned on, voltage is supplied to other side of EFI main relay from the ignition switch. EFI main relay is then energized and provides battery voltage to circuit opening relay, +B terminal of Engine Control Module (ECM) and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Highlander)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, +B terminal of ECM and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (MR2)

EFI main relay may also be referred to as EFI relay. EFI No. 1 fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, +B terminal of ECM and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Prius)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, +B terminal of ECM and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (RAV4)

EFI main relay may also be referred to as EFI relay. EFI No. 2 fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, A/F heater relay, +B terminal of ECM and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Tacoma)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. When ignition is turned on, voltage is supplied through IGN fuse to other side of EFI main relay. EFI main relay is then energized and provides battery voltage to circuit opening relay, +B terminal of Engine Control Module (ECM), data link connector No. 1 and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI MAIN RELAY LOCATION

IGNITION SYSTEMS

Note. All models use a distributorless ignition system.

Camry CNG & Gasoline Models, & Camry Solara

1. Disconnect spark plug wires. Remove spark plugs. Install spark plug on each spark plug wire. Ground spark plug against cylinder block.
2. Crank engine and check for spark. Spark test is based on the assumption that spark plugs are okay. If spark does not exist, go to next step. If spark exists, reinstall spark plug and spark plug wires. Tighten spark plugs to 13 ft. lbs. (18 N.m).
3. Check ignition coil electrical connections. If electrical connections are okay, go to next step. If electrical connections are defective, repair as necessary and recheck for spark.
4. Using ohmmeter, check resistance of spark plug wire. Replace spark plug wire if resistance exceeds 25,000 ohms per wire. If resistance is within specification, go to next step.
5. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal (Black/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, check Black/Red wire between ignition switch and ignition coil. See WIRING DIAGRAMS article. NOTE: On Camry CNG models, it may be necessary to check operation of INJ relay by using wiring diagram. See WIRING DIAGRAMS article. INJ fuse supplies constant battery voltage to one side of INJ relay. INJ relay is energized by MREL terminal of Engine Control Module (ECM). When INJ relay is energized, INJ relay provides battery voltage to ignition coils. INJ relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of the battery.
6. Check ignition coil resistance. See «IGNITION COIL RESISTANCE»(ref-11449-S11567481312000111300000) . If ignition coil resistance is within specification, go to next step. If ignition coil resistance is not within specification, replace ignition coil. See IGNITION COIL under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-11449-S38862903782000111300000) . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR»(ref-11449-S08099321782000111300000) . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
9. Check ignition IGT signal from Engine Control Module (ECM) to ignition coil. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300 or P1310 will be set in ECM memory to indicate an ignitor circuit malfunction. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
10. If ignition IGT signal is okay, substitute another ignition coil and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignition coil. See «ENGINE CONTROL MODULE LOCATION»(ref-11449-S20546925692000111300000) table. See WIRING DIAGRAMS article. If wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m).

Celica, Corolla & ECHO

1. Remove No. 2 cylinder head cover located on top of engine, above ignition coils and valve cover. Disconnect electrical connectors at ignition coils located on top of valve cover. Remove bolts and ignition coils from valve cover. Remove spark plugs. Install spark plug on each ignition coil. Reinstall electrical connectors on ignition coils. Ground spark plugs against cylinder block.
2. Disconnect electrical connectors at fuel injectors. Crank engine and check for spark. Spark test is based on the assumption that spark plugs are okay. If spark does not exist, go to next step. If spark exists, reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m).
3. Check ignition coil electrical connections. If electrical connections are okay, go to next step. If electrical connections are defective, repair as necessary and recheck for spark.
4. Install different ignition coil on spark plug and recheck for spark. If spark still does not exist, go to next step. If spark now exists with different ignition coil, replace original ignition coil. Reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m).
5. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal. See «IGNITION COIL POSITIVE TERMINAL IDENTIFICATION»(ref-11449-S30634123372001010200000) table. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between ignition switch and ignition coil. See WIRING DIAGRAMS article. NOTE: On Celica, it may be necessary to check operation of IG2 relay by using wiring diagram. See WIRING DIAGRAMS article. IG2 fuse supplies constant battery voltage to one side of IG2 relay. When ignition is turned on, voltage is supplied from ignition switch to other side of IG2 relay and IG2 relay is then energized. When IG2 relay is energized, IG2 relay provides battery voltage to ignition coils and fuel injectors. IG2 fuse and IG2 relay are located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. IGNITION COIL POSITIVE TERMINAL IDENTIFICATION Application Wire Color Celica Black Corolla Black/White ECHO Black/Red
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-11449-S38862903782000111300000) . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR»(ref-11449-S08099321782000111300000) . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check ignition IGT signal from Engine Control Module (ECM) to ignition coil. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300, P1305, P1310 or P1315 will be set in ECM memory to indicate an ignitor circuit malfunction. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
9. If ignition IGT signal is okay, substitute another ignition coil and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignition coil. See «ENGINE CONTROL MODULE LOCATION»(ref-11449-S20546925692000111300000) table. See WIRING DIAGRAMS article. If wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m).

Highlander

1. Check for any diagnostic trouble codes. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs. If no DTCs exist, go to next step. If any DTCs exist, perform service procedure for DTC.
2. Remove No. 2 cylinder head cover located on top of engine, above ignition coils and valve cover. Disconnect electrical connectors at ignition coils located on top of valve cover. Remove bolts and ignition coils from valve cover. Remove spark plugs. Install spark plug on each ignition coil. Reinstall electrical connectors on ignition coils. Ground spark plugs against cylinder block.
3. Disconnect electrical connectors at fuel injectors. Crank engine and check for spark. If spark exists only at some spark plugs and not at other spark plugs, go to next step. If spark does not exist at any spark plug, go to step 5 . If spark exists at all spark plugs, reinstall components. Tighten spark plugs to 14 ft. lbs. (19 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).
4. Install substitute spark plug for spark plug which did not fire and recheck for spark. If spark now exists, replace original spark plug. If spark still does not exist, replace ignition coil. Reinstall components. Tighten spark plugs to 14 ft. lbs. (19 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).
5. Install substitute spark plugs and recheck for spark. If spark now exists, replace original spark plugs. If spark still does not exist, replace ignition coil that does not produce spark. Reinstall components. Tighten spark plugs to 14 ft. lbs. (19 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).

MR2

1. Remove suspension upper braces. Suspension upper brace fits between firewall and top of each strut tower. Remove No. 2 cylinder head cover located on top of engine, above ignition coils and valve cover. Disconnect electrical connectors at ignition coils mounted on valve cover. Remove bolts and ignition coils from valve cover. Remove spark plugs. Install spark plug on each ignition coil. Reinstall electrical connectors on ignition coils. Ground spark plugs against cylinder block.
2. Disconnect electrical connectors at fuel injectors. Crank engine and check for spark. Spark test is based on the assumption that spark plugs are okay. If spark does not exist, go to next step. If spark exists, reinstall components. Tighten spark plugs to 19 ft. lbs. (16 N.m), ignition coil bolts to 80 INCH lbs. (9.0 N.m) and suspension upper brace nuts to 59 ft. lbs. (80 N.m).
3. Check ignition coil electrical connections. If electrical connections are okay, go to next step. If electrical connections are defective, repair as necessary and recheck for spark.
4. Install different ignition coil on spark plug and recheck for spark. If spark still does not exist, go to next step. If spark now exists with different ignition coil, replace original ignition coil. Reinstall components. Tighten spark plugs to 19 ft. lbs. (16 N.m), ignition coil bolts to 80 INCH lbs. (9.0 N.m) and suspension upper brace nuts to 59 ft. lbs. (80 N.m).
5. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal (Black/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between IG2 relay and ignition coil. See WIRING DIAGRAMS article. IG2 fuse supplies constant battery voltage to one side of IG2 relay. When ignition is turned on, voltage is supplied from ignition switch to other side of IG2 relay and IG2 relay is then energized. When IG2 relay is energized, IG2 relay provides battery voltage to ignition coils and fuel injectors. If necessary to check operation of IG2 relay, see IG2 RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article. IG2 fuse is located in fuse/relay box at driver's side rear corner of engine compartment, just in front of strut tower. IG2 relay is located in relay box on firewall at driver's side front corner of engine compartment.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-11449-S38862903782000111300000) . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR»(ref-11449-S08099321782000111300000) . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check ignition IGT signal from Engine Control Module (ECM) to ignition coil. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300, P1305, P1310 or P1315 will be set in ECM memory to indicate an ignitor circuit malfunction. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
9. If ignition IGT signal is okay, substitute another ignition coil and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignition coil. See «ENGINE CONTROL MODULE LOCATION»(ref-11449-S20546925692000111300000) table. See WIRING DIAGRAMS article. If wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Tighten spark plugs to 19 ft. lbs. (16 N.m), ignition coil bolts to 80 INCH lbs. (9.0 N.m) and suspension upper brace nuts to 59 ft. lbs. (80 N.m).

1. Remove air cleaner assembly for access to ignition coils located on top of valve cover. Disconnect electrical connectors at ignition coils. Remove bolts and ignition coils from valve cover. Remove spark plugs. Install spark plug on each ignition coil. Reinstall electrical connectors on ignition coils. Ground spark plugs against cylinder block.
2. Disconnect electrical connectors at fuel injectors. Crank engine and check for spark. Spark test is based on the assumption that spark plugs are okay. If spark does not exist, go to next step. If spark exists, reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).
3. Check ignition coil electrical connections. If electrical connections are okay, go to next step. If electrical connections are defective, repair as necessary and recheck for spark.
4. Install different ignition coil on spark plug and recheck for spark. If spark still does not exist, go to next step. If spark now exists with different ignition coil, replace original ignition coil. Reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).
5. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal (Black/White wire). If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between IG2 relay and ignition coil. See WIRING DIAGRAMS article. AM2 fuse supplies constant battery voltage to one side of IG2 relay. When ignition is turned on, voltage is supplied from ignition switch to other side of IG2 relay and IG2 relay is then energized. When IG2 relay is energized, IG2 relay provides battery voltage to ignition coils and fuel injectors. If necessary to check operation of IG2 relay, consult wiring diagram for relay testing. See WIRING DIAGRAMS article. AM2 fuse and IG2 relay are located in fuse/relay box at driver's side front corner of engine compartment.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-11449-S38862903782000111300000) . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR»(ref-11449-S08099321782000111300000) . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check ignition IGT signal from Engine Control Module (ECM) to ignition coil. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300, P1305, P1310 or P1315 will be set in ECM memory to indicate an ignitor circuit malfunction. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
9. If ignition IGT signal is okay, substitute another ignition coil and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignition coil. See «ENGINE CONTROL MODULE LOCATION»(ref-11449-S20546925692000111300000) table. See WIRING DIAGRAMS article. If wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Tighten spark plugs to 13 ft. lbs. (18 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).

RAV4

1. Remove air cleaner assembly for access to ignition coils located on top of valve cover. Disconnect electrical connectors at ignition coils. Remove bolts and ignition coils from valve cover. Remove spark plugs. Install spark plug on each ignition coil. Reinstall electrical connectors on ignition coils. Ground spark plugs against cylinder block.
2. Disconnect electrical connectors at fuel injectors. Crank engine and check for spark. Spark test is based on the assumption that spark plugs are okay. If spark does not exist, go to next step. If spark exists, reinstall components. Tighten spark plugs to 14 ft. lbs. (18 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).
3. Check ignition coil electrical connections. If electrical connections are okay, go to next step. If electrical connections are defective, repair as necessary and recheck for spark.
4. Install different ignition coil on spark plug and recheck for spark. If spark still does not exist, go to next step. If spark now exists with different ignition coil, replace original ignition coil. Reinstall components. Tighten spark plugs to 14 ft. lbs. (18 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).
5. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal (Black/White wire). If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between IG2 relay and ignition coil. See WIRING DIAGRAMS article. IGN fuse supplies constant battery voltage to one side of IG2 relay. When ignition is turned on, voltage is supplied from ignition switch, through IG2 fuse and to other side of IG2 relay and IG2 relay is then energized. When IG2 relay is energized, IG2 relay provides battery voltage to ignition coils and fuel injectors. If necessary to check operation of IG2 relay, see IG2 RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article. IGN fuse and IG2 relay are located in fuse/relay box at driver's side front corner of engine compartment. IG2 fuse is located in fuse box behind driver's side of instrument panel.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-11449-S38862903782000111300000) . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR»(ref-11449-S08099321782000111300000) . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check ignition IGT signal from Engine Control Module (ECM) to ignition coil. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300, P1305, P1310 or P1315 will be set in ECM memory to indicate an ignitor circuit malfunction. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
9. If ignition IGT signal is okay, substitute another ignition coil and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignition coil. See «ENGINE CONTROL MODULE LOCATION»(ref-11449-S20546925692000111300000) table. See WIRING DIAGRAMS article. If wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Tighten spark plugs to 14 ft. lbs. (18 N.m) and ignition coil bolts to 80 INCH lbs. (9.0 N.m).

Tacoma

1. Remove necessary components for access to ignition coils located on top of valve cover. Disconnect electrical connectors at ignition coils. Remove bolts and ignition coils from valve cover. Remove spark plugs. Install spark plug on each ignition coil. Reinstall electrical connectors on ignition coils. Ground spark plugs against cylinder block.
2. Crank engine and check for spark. Spark test is based on the assumption that spark plugs are okay. If spark does not exist, go to next step. If spark exists, reinstall components. Tighten spark plugs to 15 ft. lbs. (20 N.m) and ignition coil bolts to 88 INCH lbs. (9.9 N.m).
3. Check ignition coil electrical connections. If electrical connections are okay, go to next step. If electrical connections are defective, repair as necessary and recheck for spark.
4. Install different ignition coil on spark plug and recheck for spark. If spark still does not exist, go to next step. If spark now exists with different ignition coil, replace original ignition coil. Reinstall components. Tighten spark plugs to 15 ft. lbs. (20 N.m) and ignition coil bolts to 88 INCH lbs. (9.9 N.m).
5. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal (Black/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, check Black/Red wire between ignition switch and ignition coil. See WIRING DIAGRAMS article.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-11449-S38862903782000111300000) . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR»(ref-11449-S08099321782000111300000) . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check ignition IGT signal from Engine Control Module (ECM) to ignition coil. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300, P1305, P1310 or P1315 will be set in ECM memory to indicate an ignitor circuit malfunction. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
9. If ignition IGT signal is okay, substitute another ignition coil and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignition coil. See «ENGINE CONTROL MODULE LOCATION»(ref-11449-S20546925692000111300000) table. See WIRING DIAGRAMS article. If wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Tighten spark plugs to 15 ft. lbs. (20 N.m) and ignition coil bolts to 88 INCH lbs. (9.9 N.m). ENGINE CONTROL MODULE LOCATION Model (1) Location Camry CNG & Gasoline Models, & Camry Solara Behind Glove Box Celica In Engine Compartment, Below Cover, Just In Front Of Battery, Next To Driver's Side Strut Tower Corolla Behind Stereo On Instrument Panel, Just In Front Of Center Console ECHO & Highlander Behind Glove Box MR2 On Inside Of Firewall, Directly Behind Driver's Seat & Luggage Compartment Prius Behind Glove Box RAV4 Near Passenger's Side Kick Panel, Just Below Instrument Panel Tacoma Behind Glove Box (1) For illustration of ECM location, see THEORY & OPERATION article.

1. Disconnect electrical connector at camshaft position sensor. Camshaft position sensor is located at timing belt end of cylinder head, on firewall side of engine. (Scheme 37) Using ohmmeter, check resistance between electrical terminals on camshaft position sensor.
2. Ensure camshaft position sensor resistance is within specification. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S42922286002000111300000) table. Replace camshaft position sensor if resistance is not within specification. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

Celica & Corolla

1. Camshaft position sensor may also be referred to Variable Valve Timing (VVT) sensor. Disconnect electrical connector at camshaft position sensor. Camshaft position sensor is located just above intake manifold on cylinder head, at flywheel end of engine. (Scheme 38)and (Scheme 39). Using ohmmeter, check resistance between electrical terminals on camshaft position sensor.
2. Ensure camshaft position sensor resistance is within specification. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S42922286002000111300000) table. Replace camshaft position sensor if resistance is not within specification. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

ECHO & Highlander

1. Camshaft position sensor may also be referred to Variable Valve Timing (VVT) sensor. Disconnect electrical connector at camshaft position sensor. Camshaft position sensor is located on end of cylinder head at flywheel end of engine. (Scheme 40)and (Scheme 41). Using ohmmeter, check resistance between electrical terminals on camshaft position sensor.
2. Ensure camshaft position sensor resistance is within specification. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S42922286002000111300000) table. Replace camshaft position sensor if resistance is not within specification. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

1. Camshaft position sensor may also be referred to Variable Valve Timing (VVT) sensor. Camshaft position sensor is located just above intake manifold on cylinder head, at flywheel end of engine. (Scheme 42)
2. Manufacturer recommends removing camshaft position sensor from cylinder head before checking the resistance. Remove camshaft position sensor. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
3. Using ohmmeter, check resistance between electrical terminals on camshaft position sensor. Ensure camshaft position sensor resistance is within specification. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S42922286002000111300000) table. Replace camshaft position sensor if resistance is not within specification. Reinstall camshaft position sensor.

Prius & RAV4

1. On all models, camshaft position sensor may also be referred to Variable Valve Timing (VVT) sensor. Disconnect electrical connector at camshaft position sensor. Camshaft position sensor is located on end of cylinder head at flywheel end of engine. (Scheme 43)and (Scheme 44). Using ohmmeter, check resistance between electrical terminals on camshaft position sensor.
2. Ensure camshaft position sensor resistance is within specification. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S42922286002000111300000) table. Replace camshaft position sensor if resistance is not within specification. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

1. Disconnect electrical connector at camshaft position sensor. Camshaft position sensor is located on cylinder head, just in front of intake manifold. (Scheme 45) Using ohmmeter, check resistance between electrical terminals on camshaft position sensor.
2. Ensure camshaft position sensor resistance is within specification. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S42922286002000111300000) table. Replace camshaft position sensor if resistance is not within specification. See CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

CAMSHAFT POSITION SENSOR RESISTANCE

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

1. Disconnect crankshaft position sensor electrical connector located near front of engine, just below generator. (Scheme 46) Crankshaft position sensor is located behind lower timing belt cover, near crankshaft sprocket.
2. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor electrical connector. Ensure crankshaft position sensor resistance is within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Replace crankshaft position sensor if resistance is not within specification. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector.

1. Crankshaft position sensor is located on front of engine, near crankshaft pulley. (Scheme 47)
2. Manufacturer recommends removing crankshaft position sensor before checking the resistance. Manufacturer states intake manifold must be removed for removal of crankshaft position sensor. Remove crankshaft position sensor. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
3. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor. Replace crankshaft position sensor if resistance is not within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Reinstall crankshaft position sensor.

ECHO

1. Remove passenger's side engine cover for access to crankshaft pulley. Disconnect crankshaft position sensor electrical connector at crankshaft position sensor. Crankshaft position sensor is located on front of engine, near crankshaft pulley. (Scheme 48)
2. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor. Ensure crankshaft position sensor resistance is within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Replace crankshaft position sensor if resistance is not within specification. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector.

1. Disconnect crankshaft position sensor electrical connector at crankshaft position sensor. Crankshaft position sensor is located on front of timing chain cover. (Scheme 49)
2. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor electrical connector. Ensure crankshaft position sensor resistance is within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Replace crankshaft position sensor if resistance is not within specification. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector.

1. Remove lower front engine cover. Remove A/C compressor for access to crankshaft position sensor. It may be necessary to discharge A/C system for removal of A/C compressor. Crankshaft position sensor is located on front of timing chain cover, near crankshaft pulley. (Scheme 50)
2. Disconnect crankshaft position sensor electrical connector. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor electrical connector. Ensure crankshaft position sensor resistance is within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Replace crankshaft position sensor if resistance is not within specification. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector and A/C compressor. Tighten A/C compressor retaining bolts to 18 ft. lbs. (24 N.m). Install lower front engine cover.

1. Remove passenger's side engine cover for access to crankshaft pulley. Disconnect crankshaft position sensor electrical connector at crankshaft position sensor. Crankshaft position sensor is located on front of engine, near crankshaft pulley. (Scheme 51)
2. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor. Ensure crankshaft position sensor resistance is within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Replace crankshaft position sensor if resistance is not within specification. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector and passenger's side engine cover.

1. Disconnect crankshaft position sensor electrical connector located near front of engine. (Scheme 52) Crankshaft position sensor is located on timing chain cover, near crankshaft pulley.
2. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor electrical connector. Ensure crankshaft position sensor resistance is within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Replace crankshaft position sensor if resistance is not within specification. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector.

1. Crankshaft position sensor is located near crankshaft pulley, just above oil pan on driver's side of engine. (Scheme 53)
2. Manufacturer recommends removing crankshaft position sensor before checking the resistance. See CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
3. Using ohmmeter, check resistance between NE- and NE+ terminals on crankshaft position sensor. (Scheme 53) Replace crankshaft position sensor if resistance is not within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-11449-S39486665372000111300000) table. Reinstall crankshaft position sensor.

CRANKSHAFT POSITION SENSOR RESISTANCE

Scheme 46

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

1. Ignition coil primary resistance cannot be checked. Only ignition coil secondary resistance may be checked. Disconnect spark plug wires and electrical connectors from ignition coil.
2. Using ohmmeter, check ignition coil secondary resistance between spark plug wire terminals on ignition coil. (Scheme 54) Ensure ignition coil secondary resistance is within specification. See «IGNITION COIL RESISTANCE»(ref-11449-S05634560372000111300000) table. Replace ignition coil if ignition coil secondary resistance is not within specification. See IGNITION COIL under IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall spark plug wires and electrical connector. IGNITION COIL RESISTANCE - Ohms Temperature Primary Secondary Cold (1) (2) 9700-16,700 Hot (3) (2) 12,400-19,600 (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Primary ignition coil resistance cannot be measured. (3) Hot is with temperature of 122-212°F (50-100°C).

Celica, Corolla, ECHO, Highlander, MR2, Prius, RAV4 & Tacoma

Ignition coil testing procedure and resistance are not available from manufacturer.

IDLE SPEED & IGNITION TIMING

Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.

SUMMARY

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to appropriate SELF-DIAGNOSTICS article. If no hard diagnostic trouble codes are found in self-diagnostics, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.