Engine Controls - Basic Diagnostic Procedures - 4-CYLINDER: Other Toyota 4Runner III

Compression (Camry, Camry Solara, Celica, Corolla & RAV4)

Warm engine to normal operating temperature before checking the compression. Ensure battery is fully charged. Disconnect electrical connector(s) at ignition coil(s). 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. 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-91199-S33030528232001030500000) table. Install and tighten spark plugs to 15 ft. lbs. (20 N.m).

COMPRESSION SPECIFICATIONS

FUEL SYSTEM

Basic diagnosis of fuel system should begin by checking fuel pump operation and fuel pressure.

FUEL PRESSURE RELEASE

1. Disconnect electrical connector for fuel pump. See «FUEL PUMP ELECTRICAL CONNECTOR LOCATION»(ref-91199-S01506693162001030500000) 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, Camry Solara, Celica & Corolla Under Cover Plate, Below Rear Seat 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 fuel line connection, allowing fuel pressure to be released. Once fuel pressure is released, fuel system components may be serviced.

Camry & Camry Solara

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-91199-S20855559572001030500000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel filter. (Scheme 14) 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 14) 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 8
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 SYSTEM 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.

Celica

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-91199-S20855559572001030500000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel filter. (Scheme 14) Remove union bolt with gaskets, and disconnect fuel inlet hose from fuel filter.
3. Install fuel pressure gauge from Fuel Pressure Gauge Set (SST 09268-45012) with fuel inlet hose, gaskets and union bolt on fuel filter. (Scheme 14) 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 3 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 9
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 SYSTEM 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 33-38 psi (2.3-2.7 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 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 14

Scheme 15

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-91199-S20855559572001030500000). Disconnect negative battery cable.
2. Purchase fuel pipe Part No. (23901-22010) from parts department. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 15)
3. Remove fuel pipe clamp from end of fuel pipe at end of fuel rail. Perform STEP 1. (Scheme 16) 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. (Scheme 16)
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 17) 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 4 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
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 SYSTEM 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 16

Scheme 17

RAV4

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-91199-S20855559572001030500000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel filter. (Scheme 14) Remove air cleaner assembly and fuse/relay box at driver's side front corner of engine compartment for access to fuel filter. 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 14) 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 5 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 11
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 SYSTEM 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.

Tacoma & 4Runner

1. Ensure battery is fully charged. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-91199-S20855559572001030500000). Disconnect negative battery cable.
2. Note location for fuel pressure gauge installation on fuel rail. (Scheme 18) Fuel pressure gauge is installed at firewall end of fuel rail, between fuel rail and fuel inlet pipe. 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 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 6and see scheme 7. 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 12and 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 rail. See FUEL SYSTEM 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 18

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.

Circuit Opening Relay (Camry & 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)

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 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 (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 & 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. 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 (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 (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 CHECKS (DISTRIBUTOR TYPE IGNITION SYSTEM)

Note. Distributor type ignition system is only used on Celica models. For testing of distributorless ignition system on Camry, Camry Solara, Corolla, RAV4, Tacoma and 4Runner, see IGNITION CHECKS (DISTRIBUTORLESS IGNITION SYSTEM) .

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 electrical connection at ignition coil, ignitor and distributor. Ignitor is located near ignition coil mounted on firewall, near brake booster.
3. 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 and ignition coil high tension wires. Replace high tension wire if resistance exceeds 25,000 per ohms per wire. If resistance is within specification, go to next step.
5. Turn ignition on. Using voltmeter, check for battery voltage at ignitor and 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, ignition coil and ignitor.
6. Check ignition coil resistance. See «IGNITION COIL RESISTANCE»(ref-91199-S13936484732001030500000) . If ignition coil resistance is within specification, go to next step. If ignition coil resistance is not within specification, replace ignition coil. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check pick-up coil resistance. See «PICK-UP COIL RESISTANCE»(ref-91199-S06651508882001030500000) . If pick-up coil resistance is within specification, go to next step. If pick-up coil resistance is not within specification, replace distributor assembly. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S30173069422001030500000) . 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 SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
9. Check pick-up coil air gap. See «PICK-UP COIL AIR GAP»(ref-91199-S09706541242001030500000) . If pick-up coil air gap is correct, go to next step. If pick-up coil air gap is incorrect, replace distributor assembly. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
10. Check ignition IGT signal from Engine Control Module (ECM) to ignitor. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300 will be set in ECM memory to indicate an ignitor circuit malfunction. See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.
11. If ignition IGT signal is okay, substitute another ignitor and recheck system operation. If ignition IGT signal is defective, check wiring between ECM, distributor and ignitor. ECM is located below passenger's side of instrument panel, underneath carpet near center console. For illustration of ECM location, see THEORY & OPERATION 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. Install and tighten spark plugs to 13 ft. lbs. (18 N.m).

1. Crankshaft position sensor is located behind lower timing belt cover, near crankshaft sprocket. Disconnect crankshaft position sensor electrical connector located near generator. (Scheme 19)
2. Using ohmmeter, check resistance between electrical terminals on crankshaft position sensor electrical connector. Ensure crankshaft position sensor resistance is within specification. See «DISTRIBUTOR TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S19444231432001030500000) table.
3. Replace crankshaft position sensor if resistance is not within specification. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector.

DISTRIBUTOR TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE

Scheme 19

1. Disconnect wiring from ignition coil so ignition coil is isolated from the system. Using an ohmmeter, check ignition coil primary resistance between ignition coil positive (+) and negative (-) terminals. (Scheme 20)
2. Check ignition coil secondary resistance between ignition coil positive (+) terminal and high tension terminal (coil wire tower). (Scheme 20)
3. Ensure ignition coil resistance is within specification. See «DISTRIBUTOR TYPE IGNITION SYSTEM IGNITION COIL RESISTANCE»(ref-91199-S32443069372001030500000) table. Replace ignition coil if resistance is not within specification. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.

DISTRIBUTOR TYPE IGNITION SYSTEM IGNITION COIL RESISTANCE - Ohms

Scheme 20

1. Disconnect electrical connector on distributor. Using ohmmeter, check resistance between terminals on distributor for pick-up coil. (Scheme 21)
2. Ensure pick-up coil resistance is within specification. See «PICK-UP COIL RESISTANCE SPECIFICATIONS»(ref-91199-S13466300252001030500000) table. Replace distributor assembly if pick-up coil resistance is not within specification. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector.

PICK-UP COIL RESISTANCE SPECIFICATIONS

Scheme 21

Remove distributor cap. Using non-magnetic feeler gauge, check pick-up coil air gap between signal rotor and pick-up coil projection. (Scheme 22) Replace distributor assembly if pick-up coil air gap is not.008-.018" (.20-.45 mm). See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.

Scheme 22

IGNITION CHECKS (DISTRIBUTORLESS IGNITION SYSTEM)

Note. All models except Celica, use a distributorless ignition system. Celica uses a distributor type ignition system. For testing of distributor type ignition system on Celica, see IGNITION CHECKS (DISTRIBUTOR TYPE IGNITION SYSTEM) .

Camry, Camry Solara, Corolla, RAV4, Tacoma & 4Runner

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 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-91199-S01959709332001030500000) . If ignition coil resistance is within specification, go to next step. If ignition coil resistance is not within specification, replace ignition coil. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Check resistance of camshaft position sensor. See «CAMSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S26814264032001030500000) . 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 SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
7. Check resistance of crankshaft position sensor. See «CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S20000877972001030500000) . 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 SYSTEM 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 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-91199-S35630889882001030500000) 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.
10. On Camry, Camry Solara, Corolla and RAV4, install and tighten spark plugs to 13 ft. lbs. (18 N.m). On Tacoma and 4Runner, install and tighten spark plugs to 15 ft. lbs. (20 N.m). ECM LOCATION Model (1) Location Camry & Camry Solara Behind Glove Box Corolla Behind Stereo On Instrument Panel, Just In Front Of Center Console RAV4 Behind Instrument Panel, Near Front Of Center Console Tacoma & 4Runner Behind Glove Box (1) For illustration of ECM location, see THEORY & OPERATION article.

Scheme 23

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 23) Ensure ignition coil secondary resistance is within specification. See «DISTRIBUTORLESS TYPE IGNITION SYSTEM IGNITION COIL RESISTANCE»(ref-91199-S03073519872001030500000) table. Replace ignition coil if ignition coil secondary resistance is not within specification. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall spark plug wires and electrical connector. DISTRIBUTORLESS TYPE IGNITION SYSTEM IGNITION COIL RESISTANCE - Ohms Application Primary Secondary Camry, Camry Solara, Corolla, RAV4, Tacoma & 4Runner 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) Ignition coil primary cannot be checked. (3) Hot is with temperature of 122-212°F (50-100°C).

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 24) 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-91199-S04687657502001030500000) table. Replace camshaft position sensor if resistance is not within specification. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

Corolla

1. 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 25) 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-91199-S04687657502001030500000) table. Replace camshaft position sensor if resistance is not within specification. See IGNITION SYSTEM 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 24) 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-91199-S04687657502001030500000) table. Replace camshaft position sensor if resistance is not within specification. See IGNITION SYSTEM 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 26) 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-91199-S04687657502001030500000) table. Replace camshaft position sensor if resistance is not within specification. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on camshaft position sensor.

CAMSHAFT POSITION SENSOR RESISTANCE

Scheme 24

Scheme 25

Scheme 26

1. Disconnect crankshaft position sensor electrical connector located near front of engine, just below generator. (Scheme 27) 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 «DISTRIBUTORLESS TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S11620628922001030500000) table.
3. Replace crankshaft position sensor if resistance is not within specification. See IGNITION SYSTEM 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 28)
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 SYSTEM 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 «DISTRIBUTORLESS TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S11620628922001030500000) table. Reinstall crankshaft position sensor.

1. Disconnect crankshaft position sensor electrical connector located near front of engine, just below generator. (Scheme 29) 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. Ensure crankshaft position sensor resistance is within specification. See «DISTRIBUTORLESS TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S11620628922001030500000) table.
3. Replace crankshaft position sensor if resistance is not within specification. See IGNITION SYSTEM 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 30)
2. Manufacturer recommends removing crankshaft position sensor before checking the resistance. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
3. Using ohmmeter, check resistance between NE- and NE+ terminals on crankshaft position sensor. (Scheme 30) Replace crankshaft position sensor if resistance is not within specification. See «DISTRIBUTORLESS TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-91199-S11620628922001030500000) table. Reinstall crankshaft position sensor.

DISTRIBUTORLESS TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE

Scheme 27

Scheme 28

Scheme 29

Scheme 30

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.