Engine Controls - Basic Diagnostic Procedures - 4-CYLINDER: Other Toyota Celica T230

Compression (Camry CNG & Gasoline Models, Camry Solara, Celica, Corolla, ECHO & RAV4)

Warm engine to normal operating temperature before checking the compression. Ensure battery is fully charged. Disconnect electrical connector(s) at ignition coil(s). Remove 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 (Tacoma & 4Runner)

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 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-2888-S40400242472000041400000) table. Install and tighten spark plugs to 15 ft. lbs. (20 N.m).

COMPRESSION SPECIFICATIONS

FUEL SYSTEMS

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.

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

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 16

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 16)
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 17

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 17) 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, RAV4, Tacoma & 4Runner

1. Disconnect electrical connector for fuel pump. See «FUEL PUMP ELECTRICAL CONNECTOR LOCATION»(ref-2888-S24745869902000041400000) 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 Under Cover Plate, Below Rear Seat Cushion RAV4 Under Cover Plate, Below Driver's Side Rear Seat Tacoma & 4Runner 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.

Only fuel pressure specification is available from manufacturer. Information is not available from manufacturer for checking fuel pressure. 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 121-135 psi (8.5-9.5 kg/cm 2 ).

Camry Gasoline Models & Camry Solara

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-2888-S10206900842000041400000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel filter. (Scheme 18) 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 18) Tighten union bolt to 21 ft. lbs. (29 N.m).
4. Reconnect negative battery cable. Install scan tool on data link connector No. 3. see scheme 1and see scheme 2. Turn ignition on. DO NOT start engine.
5. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump and note fuel pressure. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ). NOTE: Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 9
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 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 scan tool 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 using scan tool to energize fuel pump.

Scheme 18

Scheme 19

Scheme 20

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-2888-S10206900842000041400000). Disconnect negative battery cable.
2. Purchase appropriate fuel pipe from parts department. See «FUEL PIPE IDENTIFICATION»(ref-2888-S23236868242000041400000) table. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 19)and (Scheme 20). 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
3. Remove fuel pipe clamp from end of fuel pipe at end of fuel rail. Perform STEP 1 in illustration. (Scheme 21)- (Scheme 23). Ensure area around fuel pipe and disconnect fitting is clean. CAUTION: Use care when disconnecting fuel pipe, as some residual fuel pressure may still exist in the fuel system.
4. Depress both sides of retainer and pull fuel pipe with disconnect fitting from fuel pipe fitting. Perform STEP 2 in illustration. (Scheme 21)- (Scheme 23).
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 24) Ensure hose, fuel pipe and fuel pipe connector are properly connected.
6. Install negative battery cable. Connect scan tool to data link connector No. 3. see scheme 3- see scheme 5. Turn ignition on. DO NOT start engine.
7. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump and note fuel pressure. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ). NOTE: Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 10- see scheme 12.
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 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 scan tool 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 using scan tool to energize fuel pump.

Scheme 21

Scheme 22

Scheme 23

Scheme 24

RAV4

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-2888-S10206900842000041400000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel filter. (Scheme 18) Remove air cleaner assembly and fuse/relay box at driver's side front corner of engine compartment for access to fuel filter. 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 18) Tighten union bolt to 21 ft. lbs. (29 N.m).
4. Reconnect negative battery cable. Install scan tool on data link connector No. 3. see scheme 6 Turn ignition on. DO NOT start engine.
5. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump and note fuel pressure. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ). NOTE: Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 13
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 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 scan tool 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 using scan tool to energize fuel pump. Reinstall fuse/relay box and air cleaner assembly.

Tacoma & 4Runner

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-2888-S10206900842000041400000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel rail. (Scheme 25) 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 25) Tighten union bolt to 21 ft. lbs. (29 N.m).
4. Reconnect negative battery cable. Install scan tool on data link connector No. 3. see scheme 7and see scheme 8. Turn ignition on. DO NOT start engine.
5. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump and note fuel pressure. Fuel pressure should be 38-44 psi (2.7-3.1 kg/cm 2 ). NOTE: Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 14and see scheme 15.
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 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 scan tool 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 using scan tool to energize fuel pump.

Scheme 25

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 appropriate wiring diagram in 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)

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)

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 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 (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. 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 one side of circuit opening relay. When engine is cranking, circuit opening relay receives a start signal which energizes circuit opening relay. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. When start signal is released from circuit opening relay, Engine Control Module (ECM) then controls the ground circuit for circuit opening relay 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 (4Runner)

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, data link connector No. 1 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of ECM. 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, data link connector No. 1 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of ECM. 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 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of Engine Control Module (ECM) when ignition is turned on. 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 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of Engine Control Module (ECM) when ignition is turned on. 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 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of Engine Control Module (ECM) when ignition is turned on. 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 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, data link connector No. 1 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of Engine Control Module (ECM) when ignition is turned on. For EFI main relay location, see EFI MAIN RELAY LOCATION table.

EFI Main Relay (Tacoma & 4Runner)

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, data link connector No. 1 and various other electrical components. EFI main relay also provides battery voltage to +B terminal of Engine Control Module (ECM) when ignition is turned on. 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 & RAV4

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. If spark does not exist, 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.
3. 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.
4. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3309) article. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between ignition switch and ignition coil. NOTE: On Camry CNG models, it may be necessary to check operation of INJ relay by using wiring diagram. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3309) 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. NOTE: On RAV4, it may be necessary to check operation of IG2 relay by using wiring diagram. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3309) article. IGN 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 relay is located in relay box at driver's side front corner of engine compartment, just in front of strut tower.
5. Check ignition coil resistance. See «IGNITION COIL RESISTANCE»(ref-2888-S03609946222000041400000) . If ignition coil resistance is within specification, go to next step. If ignition coil resistance is not within specification, replace ignition coil. See IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S20343976932000041400000) . 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 IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S02342561402000041400000) . 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 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 or P1310 will be set in ECM memory to indicate an ignitor circuit malfunction. See SELF-DIAGNOSTIC SYSTEM in «SELF-DIAGNOSTICS - INTRODUCTION»(ref-3290) 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 «ECM LOCATION»(ref-2888-S12043541192000041400000) table. 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 mounted 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. If spark does not exist, 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.
3. 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.
4. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal. See appropriate wiring diagram in WIRING DIAGRAMS article. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between ignition switch and ignition coil. NOTE: On Celica, it may be necessary to check operation of IG2 relay by using wiring diagram. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3309) 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 relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower, near battery.
5. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S20343976932000041400000) . 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 IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S02342561402000041400000) . 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 IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. 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 SELF-DIAGNOSTIC SYSTEM in «SELF-DIAGNOSTICS - INTRODUCTION»(ref-3290) article for retrieving of DTCs.
8. 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 «ECM LOCATION»(ref-2888-S12043541192000041400000) table. 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). On Celica and ECHO, tighten ignition coil bolts to 80 INCH lbs. (9.0 N.m). On Corolla, tighten ignition coil bolts to 62 INCH lbs. (7.0 N.m).

Tacoma 2.4L 4-Cyl. Calif. Emission Vehicles, Tacoma 2.7L 4-Cyl. Calif. Emission Vehicles & 4Runner 2.7L 4-Cyl. Calif. Emission Vehicles)

1. Disconnect electrical connectors at ignition coils mounted 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. CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 2 seconds when checking for spark.
2. Crank engine and check for spark. If spark does not exist, 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.
3. 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.
4. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3309) article. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between ignition switch and ignition coil.
5. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S20343976932000041400000) . 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 IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S02342561402000041400000) . 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 IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. 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 SELF-DIAGNOSTIC SYSTEM in «SELF-DIAGNOSTICS - INTRODUCTION»(ref-3290) article for retrieving of DTCs.
8. 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 «ECM LOCATION»(ref-2888-S12043541192000041400000) table. 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).

Tacoma 2.4L 4-Cyl. Except Calif. Emission Vehicles, Tacoma 2.7L 4-Cyl. Except Calif. Emission Vehicles & 4Runner 2.7L 4-Cyl. Except Calif. Emission Vehicles

1. Disconnect spark plug wires. Remove spark plugs. Install spark plug on each spark plug wire. Ground spark plug against cylinder block. CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 2 seconds when checking for spark.
2. Crank engine and check for spark. If spark does not exist, 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.
3. 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.
4. Turn ignition on. Using voltmeter, check for battery voltage at ignition coil positive terminal. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-3309) article. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between ignition switch and ignition coil.
5. Check ignition coil resistance. See «IGNITION COIL RESISTANCE»(ref-2888-S03609946222000041400000) . If ignition coil resistance is within specification, go to next step. If ignition coil resistance is not within specification, replace ignition coil. See IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S20343976932000041400000) . 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 IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S02342561402000041400000) . 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 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 or P1310 will be set in ECM memory to indicate an ignitor circuit malfunction. See SELF-DIAGNOSTIC SYSTEM in «SELF-DIAGNOSTICS - INTRODUCTION»(ref-3290) 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 «ECM LOCATION»(ref-2888-S12043541192000041400000) table. 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).

ECM LOCATION

Scheme 26

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 26) Ensure ignition coil secondary resistance is within specification. See «IGNITION COIL RESISTANCE»(ref-2888-S23579351672000041400000) table. Replace ignition coil if ignition coil secondary resistance is not within specification. See 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, Tacoma 2.4L 4-Cyl. Calif. Emission Vehicles, Tacoma 2.7L 4-Cyl. Calif. Emission Vehicles & 4Runner 2.7L 4-Cyl. Calif. Emission Vehicles

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

Camry CNG & Gasoline Models, & Camry Solara

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 27) 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-2888-S10411394892000041400000) table. Replace camshaft position sensor if resistance is not within specification. See 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 28)and (Scheme 29). 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-2888-S10411394892000041400000) table. Replace camshaft position sensor if resistance is not within specification. See IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

ECHO

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 30) 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-2888-S10411394892000041400000) table. Replace camshaft position sensor if resistance is not within specification. See 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 at timing belt end of cylinder head, on firewall side of engine. (Scheme 27) 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-2888-S10411394892000041400000) table. Replace camshaft position sensor if resistance is not within specification. See 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 at driver's side front corner of cylinder head, just in front of intake manifold. (Scheme 31) 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-2888-S10411394892000041400000) table. Replace camshaft position sensor if resistance is not within specification. See IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

CAMSHAFT POSITION SENSOR RESISTANCE

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

1. Disconnect crankshaft position sensor electrical connector located near front of engine, just below generator. (Scheme 32) 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-2888-S14446828332000041400000) table.
3. Replace crankshaft position sensor if resistance is not within specification. See 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 33)
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 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-2888-S14446828332000041400000) table. Reinstall crankshaft position sensor.

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 34)
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-2888-S14446828332000041400000) table.
3. Replace crankshaft position sensor if resistance is not within specification. See IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall crankshaft position sensor electrical connector.

1. Disconnect crankshaft position sensor electrical connector located near front of engine, just below generator. (Scheme 35) 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-2888-S14446828332000041400000) table.
3. Replace crankshaft position sensor if resistance is not within specification. See 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 36)
2. Manufacturer recommends removing crankshaft position sensor before checking the resistance. See IGNITION SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
3. Using ohmmeter, check resistance between NE- and NE+ terminals on crankshaft position sensor. (Scheme 36) Replace crankshaft position sensor if resistance is not within specification. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-2888-S14446828332000041400000) table. Reinstall crankshaft position sensor.

CRANKSHAFT POSITION SENSOR RESISTANCE

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

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.