Engine Controls - System & Component Testing - V6 & V8: Other Toyota Tundra I

ACOUSTIC CONTROL INDUCTION SYSTEM

Note. Acoustic Control Induction System (ACIS) may also be referred to as Intake Air Control Valve (IACV) system.

Scheme 81

Scheme 82

1. Acoustic Control Induction System (ACIS) uses 2 intake air control valves, one on end of air intake chamber and one near throttle bodies. (Scheme 81) Intake air control valve on end of air intake chamber may also be referred to as No. 2 intake air control valve. Intake air control valve near throttle bodies may also be referred to as No. 1 intake air control valve. Operation of actuator valve for each intake air control valve should be checked. Using 3-way connector, connect vacuum gauge in vacuum line to actuator valve for appropriate intake air control valve. (Scheme 82) Start engine. With engine idling, ensure no vacuum reading is obtained.
2. Fully open throttle and ensure vacuum reading momentarily reads approximately 7.9 in. Hg and actuator valve rod pulls inward. If actuator valve rod pulls inward, system is operating properly. If actuator valve rod does not pull inward, go to next step.
3. Disconnect vacuum hose from appropriate actuator valve. Using vacuum pump, apply 7.9 in. Hg of vacuum to actuator valve. Ensure actuator valve rod pulls inward and remains pulled inward for at least one minute. If actuator valve does not operate properly, replace intake air control valve assembly. If actuator valve operates properly, reconnect vacuum hose. Check ACIS control circuit. See «ACOUSTIC CONTROL INDUCTION SYSTEM CONTROL CIRCUIT»(ref-63408-S38637539992001020500000) under COMPUTERIZED ENGINE CONTROLS.

Scheme 83

1. Acoustic Control Induction System (ACIS) uses intake air control valve on end of air intake chamber. (Scheme 83) Using 3-way connector, connect vacuum gauge in vacuum line to actuator valve. (Scheme 83) Actuator valve is located at end of air intake chamber. Start engine. With engine idling, ensure no vacuum reading is obtained.
2. Fully open throttle and ensure vacuum reading momentarily reads approximately 7.9 in. Hg and actuator valve rod pulls inward. If actuator valve rod pulls inward, system is operating properly. If actuator valve rod does not pull inward, go to next step.
3. Disconnect vacuum hose from actuator valve. Using vacuum pump, apply 7.9 in. Hg of vacuum to actuator valve. Ensure actuator valve rod pulls inward and remains pulled inward for at least one minute. If actuator valve does not operate properly, replace intake air control valve assembly. If actuator valve operates properly, reconnect vacuum hose. Check ACIS control circuit. See «ACOUSTIC CONTROL INDUCTION SYSTEM CONTROL CIRCUIT»(ref-63408-S38637539992001020500000) under COMPUTERIZED ENGINE CONTROLS.

Scheme 84

1. Acoustic Control Induction System (ACIS) uses 2 intake air control valves, one on end of air intake chamber and one near throttle bodies. (Scheme 81) Intake air control valve on end of air intake chamber may also be referred to as No. 2 intake air control valve. Intake air control valve near throttle bodies may also be referred to as No. 1 intake air control valve. Operation of actuator valve for each intake air control valve should be checked. Using 3-way connector, connect vacuum gauge in vacuum line to actuator valve for appropriate intake air control valve. (Scheme 82)
2. Connect Toyota hand-held tester to data link connector No. 3. (Scheme 97) Start engine. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate intake air control valve No. 1 and 2 Vacuum Switching Valves (VSVs) and note vacuum reading. Intake air control valve VSVs may also be referred to as ACIS VSVs. When each intake air control valve VSV is off, ensure no vacuum reading is obtained. When each intake air control valve is on, ensure vacuum reading momentarily reads approximately 7.9 in. Hg and actuator valve rod pulls inward. If actuator valve rod does not pull inward, go to next step. If actuator valve rod pulls inward, go to step 4.
3. Disconnect vacuum hose from actuator valve. Using vacuum pump, apply 7.9 in. Hg of vacuum to actuator valve. Ensure actuator valve rod pulls inward and remains pulled inward for at least one minute. If actuator valve does not operate properly, replace intake air control valve assembly. If actuator valve operates properly, reconnect vacuum hose and go to next step.
4. Ensure transaxle is in park. While monitoring data monitor on hand-held tester, check that intake air control valve No. 1 and 2 VSVs turn on and off in relation to throttle opening percentage and engine RPM. (Scheme 84) Shut engine off. Remove hand-held tester and reconnect vacuum hose. If system operates properly, test is complete. If system does not operate as specified, check ACIS control circuit. See «ACOUSTIC CONTROL INDUCTION SYSTEM CONTROL CIRCUIT»(ref-63408-S38637539992001020500000) under COMPUTERIZED ENGINE CONTROLS.

ELECTRONIC THROTTLE CONTROL SYSTEM

Note. Electronic Throttle Control System (ETCS) may also be referred to as Electronic Throttle Control System-Intelligent (ETCS-I or ETCS-i).

Land Cruiser, Sequoia, Tundra 4.7L V8 & 4Runner

For testing of throttle body and components, see THROTTLE BODY under IDLE CONTROL SYSTEMS.

ACOUSTIC CONTROL INDUCTION SYSTEM CONTROL CIRCUIT

Note. Acoustic Control Induction System (ACIS) control circuit may also be referred to as Intake Air Control Valve (IACV) system control circuit.

Scheme 85

Scheme 86

Scheme 87

Scheme 88

Scheme 89

1. Remove "V" bank cover located on top of engine. (Scheme 85)and (Scheme 86). Disconnect electrical connector and vacuum hoses from intake air control valve Vacuum Switching Valve (VSV). (Scheme 85)and (Scheme 86). On Avalon, Highlander and Sienna, 2 intake air control valve VSVs are used. Intake air control valve No. 1 VSV is for intake air control valve near throttle bodies which may also be referred to as No. 1 intake air control valve. Intake air control valve No. 2 VSV is for intake air control valve on end of air intake chamber which may also be referred to as No. 2 intake air control valve. On all models, it may be necessary to remove emission control valve set which contains various vacuum switching valves for access to intake air control valve VSV.
2. Using ohmmeter, check that continuity exists between electrical terminals on intake air control valve VSV and that resistance is 33-39 ohms at 68°F (20°C). If continuity exists and that resistance is within specification, go to next step. If no continuity exists or resistance is not within specification, replace intake air control valve VSV.
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of intake air control valve VSV. If continuity does not exist between electrical terminal and body of intake air control valve VSV, go to next step. If continuity exists between electrical terminal and body of intake air control valve VSV, replace intake air control valve VSV.
4. Apply air pressure to port "B" on intake air control valve VSV. Ensure air flows from the filter and not from port "A". Perform STEP 1 in illustration. (Scheme 87) Apply battery voltage and ground to electrical terminals on intake air control valve VSV, or if Toyota hand-held tester is available, connect hand-held test to data link connector No. 3 and select ACTIVE TEST MODE on hand-held tester and using hand-held tester manufacturers instructions, operate intake air control valve VSV. (Scheme 94)- (Scheme 96), (Scheme 97) and (Scheme 100). Apply air pressure to port "B" on intake air control valve VSV. Ensure air flows from port "A" and not from the filter. Perform STEP 2 in illustration. (Scheme 87) If intake air control valve VSV operates properly, reinstall intake air control valve VSV and go to next step. If intake air control valve VSV does not operate properly, replace intake air control valve VSV and recheck system operation.
5. On Avalon, Camry, Camry Solara and Highlander, remove glove box for access to Engine Control Module (ECM). On Sienna, remove passenger's side lower instrument panel cover for access to Engine Control Module (ECM). On all models, for illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 104)- (Scheme 106) and (Scheme 109).. Turn ignition on. Using voltmeter, check voltage at specified ECM terminal(s). See «ECM TERMINAL IDENTIFICATION FOR INTAKE AIR CONTROL VALVE VSV»(ref-63408-S09648287102001020500000) table. This is the wire from intake air control valve VSV to ECM. ECM TERMINAL IDENTIFICATION FOR INTAKE AIR CONTROL VALVE VSV Application ECM Connector No. ECM Terminal No. & Wire Color Avalon E4 (1) 17 (Red/Yellow) E5 (2) 15 (White/Red) Camry & Camry Solara E11 17 (Red/Yellow) Highlander E9 (1) 17 (Red/Yellow) E8 (2) 15 (White/Red) Sienna E12 (1) 17 (Red/Yellow) E11 (2) 15 (Black) (1) This is for intake air control valve No. 1 VSV. (2) This is for intake air control valve No. 2 VSV.
6. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check for open and short in wiring harness and connectors between EFI main relay, intake air control valve VSV and ECM. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery and may also be referred to as EFI relay. See WIRING DIAGRAMS article.
7. On Avalon, Camry, Camry Solara and Sienna, go to next step. On Highlander, go to step 10.
8. Disconnect hoses from vacuum tank. Vacuum tank is located near driver's side front corner of engine compartment, below battery tray. Apply air pressure to port "B" on vacuum tank. Ensure air flows from port "A". Perform STEP 1 in illustration. (Scheme 88) Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2 in illustration. (Scheme 88)
9. Plug port "B". Using vacuum pump, apply 7.9 in. Hg of vacuum to port "A". Perform STEP 3 in illustration. (Scheme 88) Ensure vacuum reading will hold for at least one minute. If vacuum tank is okay, reconnect vacuum hoses and go to step 12. If vacuum tank is defective, replace vacuum tank and recheck system operation.
10. Disconnect hoses from vacuum tank. Vacuum tank is located on upper cap on air cleaner assembly. (Scheme 89) Note ports on vacuum tank. (Scheme 89) Plug port "C" on vacuum tank. Apply air pressure to port "B". Ensure air flows from port "A".
11. Plug port "C". Apply air pressure to port "A". Ensure air does not flow from port "B". Plug ports "A" and "C". Using vacuum pump, apply 24 in. Hg of vacuum to port "B". Ensure vacuum reading will hold for at least one minute. If vacuum tank is okay, reconnect vacuum hoses and go to next step. If vacuum tank is defective, replace vacuum tank or upper cap on air cleaner assembly as necessary and recheck system operation.
12. On all models, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is okay, replace ECM. If ECM is replaced and vehicle is equipped with engine immobilizer system, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

ENGINE CONTROL MODULE POWER SOURCE CIRCUIT

Note. When performing test for ECM power source circuit, it may be necessary to check wiring harness and components connected to a specified fuse, or check wiring harness and electrical connectors between EFI main relay and battery. For additional wiring information for fuse and power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS.

Avalon

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 104)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/White wire) at ECM electrical connector E8 and No. 17 (Brown wire) at ECM electrical connector E5. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E5 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Orange wire) at ECM electrical connector E8. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective AM2 fuse. AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If AM2 fuse is okay, go to next step. If AM2 fuse is defective, repair short in wiring harness and components connected to AM2 fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check for open in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Orange wire) at ECM electrical connector E8. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Blue/Orange wire) at ECM electrical connector E8. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI No. 1 and 2 fuses. EFI No. 1 and 2 fuses are located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI No. 1 and 2 fuses are okay, go to next step. If EFI No. 1 fuse or EFI No. 2 fuse is defective, repair short in wiring harness and components connected to the appropriate EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Blue/Orange wire) at ECM electrical connector E8 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI No. 1 fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Camry

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 105)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Yellow wire) at ECM electrical connector E7 and No. 17 (Brown wire) at ECM electrical connector E10. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E10 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Red wire) at ECM electrical connector E7. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check for open in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Red wire) at ECM electrical connector E7. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Black/White wire) at ECM electrical connector E7. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Black/White wire) at ECM electrical connector E7 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Camry Solara

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 105)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Red wire) at ECM electrical connector E7 and No. 17 (Brown wire) at ECM electrical connector E10. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E10 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Red wire) at ECM electrical connector E7. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check for open in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Red wire) at ECM electrical connector E7. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Black/Red wire) at ECM electrical connector E7. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Black/Red wire) at ECM electrical connector E7 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Highlander

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 106)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (White wire) at ECM electrical connector E5 and No. 17 (Brown wire) at ECM electrical connector E8. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Turn ignition off. Disconnect electrical connector E8 from ECM. Using ohmmeter, check for continuity between body ground and terminal No. 17 (Brown wire) at ECM electrical connector E8. If continuity exists, reinstall electrical connector E8 at ECM and go to next step. If continuity does not exist, repair open in Brown wire between terminal No. 17 at ECM electrical connector E8 and body ground. See WIRING DIAGRAMS article.
4. Turn ignition off. Check for open and short in White wire between EFI main relay and terminal No. 16 (White wire) at ECM electrical connector E5. See WIRING DIAGRAMS article. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. If wiring is okay, go to next step. If wiring is defective, repair as necessary.
5. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Orange wire) at ECM electrical connector E5. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 10.
6. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
7. Check for defective AM2 fuse. AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. If AM2 fuse is okay, go to next step. If AM2 fuse is defective, repair short in wiring harness and components connected to AM2 fuse. See WIRING DIAGRAMS article.
8. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
9. Check for open in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Orange wire) at ECM electrical connector E5. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
10. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Pink/Blue wire) at ECM electrical connector E5. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
11. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
12. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
13. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Pink/Blue wire) at ECM electrical connector E5 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
14. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Land Cruiser

1. Remove glove box door for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 107)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Yellow wire) at ECM electrical connector E9 and No. 17 (Brown wire) at ECM electrical connector E6. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E6 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 9 (Black/Red wire) at ECM electrical connector E9. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse/relay box behind driver's side kick panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 9 (Black/Red wire) at ECM electrical connector E9. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 5 (Black/White wire) at ECM electrical connector E9. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI fuse. EFI fuse may also be referred to as ECD fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 5 (Black/White wire) at ECM electrical connector E9 and EFI main relay, and for open in ground circuit to EFI main relay. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Sequoia

1. Remove glove box and heater duct for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 108)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Red wire) at ECM electrical connector E4 and No. 17 (Brown wire) at ECM electrical connector E7. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E7 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 9 (Black/Orange wire) at ECM electrical connector E4. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN1 fuse. IGN1 fuse is located in fuse/relay box behind driver's side of instrument panel. If IGN1 fuse is okay, go to next step. If IGN1 fuse is defective, repair short in wiring harness and components connected to IGN1 fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 9 (Black/Orange wire) at ECM electrical connector E4. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 5 (Black/White wire) at ECM electrical connector E4. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI No. 1 fuse. EFI No. 1 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI No. 1 fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 5 (Black/White wire) at ECM electrical connector E4 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI No. 1 fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Sienna

1. Remove passenger's side lower instrument panel cover for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 109)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Red wire) at ECM electrical connector E8 and No. 17 (Brown wire) at ECM electrical connector E11. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E11 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Orange wire) at ECM electrical connector E8. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Orange wire) at ECM electrical connector E8. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Yellow/Green wire) at ECM electrical connector E8. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Yellow/Green wire) at ECM electrical connector E8 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Tacoma

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 110)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (White/Red wire) at ECM electrical connector E5 and No. 17 (Brown wire) at ECM electrical connector E7. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E7 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Red wire) at ECM electrical connector E5. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Red wire) at ECM electrical connector E5. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Black/Orange wire) at ECM electrical connector E5. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
8. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Black/Orange wire) at ECM electrical connector E5 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI fuse, and between EFI fuse and EFI main relay. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Tundra 3.4L V6

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 111)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (White/Blue wire) at ECM electrical connector E3 and No. 17 (Brown wire) at ECM electrical connector E6. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E6 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Orange wire) at ECM electrical connector E3. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Orange wire) at ECM electrical connector E3. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Black/Yellow wire) at ECM electrical connector E3. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
8. Check for defective EFI No. 1 fuse. EFI No. 1 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI No. 1 fuse is okay, go to next step. If EFI No. 1 fuse is defective, repair short in wiring harness and components connected to EFI No. 1 fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Black/Yellow wire) at ECM electrical connector E3 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI No. 1 fuse, and between EFI No. 1 fuse and EFI main relay. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

Tundra 4.7L V8

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 112)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (White/Blue wire) at ECM electrical connector E3 and No. 17 (Brown wire) at ECM electrical connector E6. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E6 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 9 (Black/Orange wire) at ECM electrical connector E3. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 9 (Black/Orange wire) at ECM electrical connector E3. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 5 (Black/Yellow wire) at ECM electrical connector E3. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
8. Check for defective EFI No. 1 fuse. EFI No. 1 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI No. 1 fuse is okay, go to next step. If EFI No. 1 fuse is defective, repair short in wiring harness and components connected to EFI No. 1 fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 5 (Black/Yellow wire) at ECM electrical connector E3 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI No. 1 fuse, and between EFI No. 1 fuse and EFI main relay. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

4Runner

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminal identification. (Scheme 113)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 1 (White/Blue wire) at ECM electrical connector E14 and No. 17 (Brown wire) at ECM electrical connector E10. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E10 and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 15 (Black/Blue wire) at ECM electrical connector E14. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 15 (Black/Blue wire) at ECM electrical connector E14. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
7. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 4 (Gray/Black wire) at ECM electrical connector E14. This is the MREL terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
8. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63408-S02459929852001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. Check for open and short in wiring harness and electrical connectors between terminal No. 4 (Gray/Black wire) at ECM electrical connector E14 and EFI main relay, and for open in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
11. Check wiring harness and electrical connectors between battery and EFI fuse, and between EFI fuse and EFI main relay. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.

FUEL PUMP CONTROL CIRCUIT

Scheme 90

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 3.
2. Check operation of fuel pump by using Toyota hand-held tester. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. Ensure screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure. Fuel pressure pulsation damper is located on end of fuel rail. (Scheme 90) If screw at center of fuel pressure pulsation damper does not rise upward when fuel pump is operated to indicate fuel pressure, go to step 4. If screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-63408-S20033149102001020500000).
3. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 104)- (Scheme 106). Turn ignition on. Momentarily connect jumper wire between body ground and FC terminal at ECM to operate fuel pump. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (AVALON, CAMRY, CAMRY SOLARA & HIGHLANDER)»(ref-63408-S10290881492001020500000) table. Ensure screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure. Fuel pressure pulsation damper is located on end of fuel rail. (Scheme 90) If screw at center of fuel pressure pulsation damper does not rise upward when fuel pump is operated to indicate fuel pressure, go to next step. If screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-63408-S20033149102001020500000). ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (AVALON, CAMRY, CAMRY SOLARA & HIGHLANDER) Application ECM Connector No. ECM Terminal No. & Wire Color Avalon E8 3 (Green/Black) Camry & Camry Solara E7 3 (Green/Red) Highlander E5 3 (Green/Red)
4. Check ECM power source circuit. See «ENGINE CONTROL MODULE POWER SOURCE CIRCUIT»(ref-63408-S16514848902001020500000). If ECM power source circuit is okay, go to next step. If ECM power source circuit is defective, repair as necessary.
5. Check operation of circuit opening relay. See «CIRCUIT OPENING RELAY»(ref-63408-S39376741892001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If circuit opening relay operates properly, go to next step. If circuit opening relay is defective, replace circuit opening relay.
6. Remove glove box for access to ECM if not previously done. For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 104)- (Scheme 106).
7. Turn ignition on. Using voltmeter, check voltage between body ground and FC terminal at ECM. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (AVALON, CAMRY, CAMRY SOLARA & HIGHLANDER)»(ref-63408-S10290881492001020500000) table. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check for open in wiring harness and connectors between FC terminal at ECM and circuit opening relay, and between ignition switch and circuit opening relay. See WIRING DIAGRAMS article. On Camry, Camry Solara and Highlander, it may be necessary to check IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. On all models, repair wiring harness or electrical connectors as necessary.
8. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-63408-S12395902442001020500000) under FUEL SYSTEMS. If fuel pump resistance is within specification and fuel pump operates, go to next step. If fuel pump resistance is not within specification or fuel pump does not operate, replace fuel pump.
9. Check for open in wiring harness and electrical connectors between circuit opening relay and fuel pump, and between fuel pump and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
10. Check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

Fuel pump control circuit test is not available from manufacturer. If problem exists in fuel pump control circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Note. On Sequoia, if problem exists in fuel pump control circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM).

Scheme 91

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 3.
2. Check operation of fuel pump by using Toyota hand-held tester. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. Ensure screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure. Fuel pressure pulsation damper is located at firewall end of driver's side fuel rail. (Scheme 91) If screw at center of fuel pressure pulsation damper does not rise upward when fuel pump is operated to indicate fuel pressure, go to step 4. If screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure, go to step 11.
3. Remove glove box and heater duct for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 108) Turn ignition on. Momentarily connect jumper wire between body ground and terminal No. 6 (Green/Orange wire) at ECM electrical connector E4 to operate fuel pump. This is the FC terminal at ECM. Ensure screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure. Fuel pressure pulsation damper is located at firewall end of driver's side fuel rail. (Scheme 91) If screw at center of fuel pressure pulsation damper does not rise upward when fuel pump is operated to indicate fuel pressure, go to next step. If screw at center of fuel pressure pulsation damper rises upward when fuel pump is operated to indicate fuel pressure, go to step 11.
4. Check ECM power source circuit. See «ENGINE CONTROL MODULE POWER SOURCE CIRCUIT»(ref-63408-S16514848902001020500000). If ECM power source circuit is okay, go to next step. If ECM power source circuit is defective, repair as necessary.
5. Check operation of fuel pump relay. See «FUEL PUMP RELAY»(ref-63408-S05077195472001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If fuel pump relay operates properly, go to next step. If fuel pump relay is defective, replace fuel pump relay.
6. Check operation of circuit opening relay. See «CIRCUIT OPENING RELAY»(ref-63408-S39376741892001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If circuit opening relay operates properly, go to next step. If circuit opening relay is defective, replace circuit opening relay.
7. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-63408-S12395902442001020500000) under FUEL SYSTEMS. If fuel pump resistance is within specification and fuel pump operates, go to next step. If fuel pump resistance is not within specification or fuel pump does not operate, replace fuel pump.
8. Check for open in wiring harness and electrical connectors between fuel pump relay and fuel pump, and between fuel pump and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
9. Remove glove box and heater duct for access to ECM if not previously done. For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 108)
10. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 6 (Green/Orange wire) at ECM electrical connector E4. This is the FC terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and connectors between FC terminal at ECM and circuit opening relay, and between ignition switch and EFI main relay. See WIRING DIAGRAMS article. It may be necessary to check EFI No. 1 fuse. EFI No. 1 fuse is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Repair wiring harness or electrical connectors as necessary.
11. Check fuel pump resistor. See «FUEL DELIVERY»(ref-63408-S12395902442001020500000) under FUEL SYSTEMS. If fuel pump resistor is okay, go to next step. If fuel pump resistor is defective, replace fuel pump resistor.
12. Check for open in wiring harness and electrical connectors between fuel pump relay and fuel pump resistor, and between fuel pump resistor and fuel pump. If wiring harness and electrical connectors are okay, test is complete.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 3.
2. Check operation of fuel pump by using Toyota hand-held tester. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If fuel pump does not operate and fuel pressure does not exist in fuel inlet line at fuel pipe, go to step 4. If fuel pump operates and fuel pressure exists in fuel inlet line at fuel pipe, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-63408-S20033149102001020500000).
3. Remove passenger's side lower instrument panel cover for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 109) Turn ignition on. Momentarily connect jumper wire between body ground and terminal No. 3 (Light Green/Red wire) at ECM electrical connector E8 to operate the fuel pump. This is the FC terminal at ECM. Ensure fuel pump operates and fuel pressure exists in fuel inlet line at fuel pipe. If fuel pump does not operate and fuel pressure does not exist in fuel inlet line at fuel pipe, go to next step. If fuel pump operates and fuel pressure exists in fuel inlet line at fuel pipe, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-63408-S20033149102001020500000).
4. Check ECM power source circuit. See «ENGINE CONTROL MODULE POWER SOURCE CIRCUIT»(ref-63408-S16514848902001020500000). If ECM power source circuit is okay, go to next step. If ECM power source circuit is defective, repair as necessary.
5. Check operation of circuit opening relay. See «CIRCUIT OPENING RELAY»(ref-63408-S39376741892001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If circuit opening relay operates properly, go to next step. If circuit opening relay is defective, replace circuit opening relay.
6. Remove passenger's side lower instrument panel cover for access to ECM if not previously done. For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 109)
7. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 3 (Light Green/Red wire) at ECM electrical connector E8. This is the FC terminal at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check for open in wiring harness and connectors between terminal No. 3 (Light Green/Red wire) at ECM electrical connector E8 and circuit opening relay, and between ignition switch and circuit opening relay. See WIRING DIAGRAMS article. It may be necessary to check IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. Repair wiring harness or electrical connectors as necessary.
8. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-63408-S12395902442001020500000) under FUEL SYSTEMS. If fuel pump resistance is within specification and fuel pump operates, go to next step. If fuel pump resistance is not within specification or fuel pump does not operate, replace fuel pump.
9. Check for open in wiring harness and electrical connectors between circuit opening relay and fuel pump, and between fuel pump and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
10. Check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

Tacoma, Tundra 3.4L V6 & 4Runner

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 3.
2. Check operation of fuel pump by using Toyota hand-held tester. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If fuel pump does not operate and fuel pressure does not exist in fuel inlet line at fuel filter, go to step 4. If fuel pump operates and fuel pressure exists in fuel inlet line at fuel filter, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-63408-S20033149102001020500000).
3. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 110), (Scheme 111) and (Scheme 113). Turn ignition on. Momentarily connect jumper wire between body ground and FC terminal at ECM to operate fuel pump. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (TACOMA, TUNDRA 3.4L V6 & 4RUNNER)»(ref-63408-S14796453952001020500000) table. Ensure fuel pump operates and fuel pressure exists in fuel inlet line at fuel filter. If fuel pump does not operate and fuel pressure does not exist in fuel inlet line at fuel filter, go to next step. If fuel pump operates and fuel pressure exists in fuel inlet line at fuel filter, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-63408-S20033149102001020500000). ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (TACOMA, TUNDRA 3.4L V6 & 4RUNNER) Application ECM Connector No. ECM Terminal No. & Wire Color Tacoma E5 3 (White/Blue) Tundra 3.4L V6 E3 3 (Yellow) 4Runner E14 22 (Green/Yellow)
4. Check ECM power source circuit. See «ENGINE CONTROL MODULE POWER SOURCE CIRCUIT»(ref-63408-S16514848902001020500000). If ECM power source circuit is okay, go to next step. If ECM power source circuit is defective, repair as necessary.
5. Check operation of circuit opening relay. See «CIRCUIT OPENING RELAY»(ref-63408-S39376741892001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If circuit opening relay operates properly, go to next step. If circuit opening relay is defective, replace circuit opening relay.
6. Remove glove box for access to ECM if not previously done. For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 110), (Scheme 111) and (Scheme 113).
7. Turn ignition on. Using voltmeter, check voltage between body ground and FC terminal at ECM. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (TACOMA, TUNDRA 3.4L V6 & 4RUNNER)»(ref-63408-S14796453952001020500000) table. Voltage should be 9-14 volts. If voltage is within specification, go to next step. On Tacoma and Tundra, if voltage is not within specification, check for open in wiring harness and connectors between FC terminal at ECM and circuit opening relay, and between EFI main relay and circuit opening relay. See WIRING DIAGRAMS article. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery. On 4Runner, if voltage is not within specification, check for open in wiring harness and connectors between FC terminal at ECM and circuit opening relay, and between ignition switch and circuit opening relay. See WIRING DIAGRAMS article. It may be necessary to check IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. On all models, repair wiring harness or electrical connectors as necessary.
8. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-63408-S12395902442001020500000) under FUEL SYSTEMS. If fuel pump resistance is within specification and fuel pump operates, go to next step. If fuel pump resistance is not within specification or fuel pump does not operate, replace fuel pump.
9. Check for open in wiring harness and electrical connectors between circuit opening relay and fuel pump, and between fuel pump and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary.
10. Check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On 4Runner models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

Fuel pump control circuit test is not available from manufacturer. If problem exists in fuel pump control circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

STARTER SIGNAL CIRCUIT

Note. Starter signal circuit is mainly used to increase fuel injection volume during engine starting. Starter signal circuit test is based on the premise that engine cranks normally. If engine will not crank, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.

Note. When performing starter signal circuit test, it may be necessary to consult the starter wiring diagram for the entire wiring circuit. For starter wiring diagram, see WIRING DIAGRAMS in appropriate STARTERS article in STARTING & CHARGING SYSTEMS.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 94) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Black/Red wire and electrical connectors between terminal No. 7 at Engine Control Module (ECM) electrical connector E8 and starter relay. See WIRING DIAGRAMS article. This is the STA terminal at ECM. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery and may be marked as ST relay. For ECM electrical connector terminal identification (Scheme 104)
4. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 104) Using voltmeter, check voltage between body ground and terminal No. 7 (Black/Red wire) at ECM electrical connector E8 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
6. Check for open and short in Black/Red wire and electrical connectors between terminal No. 7 at ECM electrical connector E8 and starter relay. See WIRING DIAGRAMS article. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery and may be marked as ST relay.
7. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

Scheme 92

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 95)and (Scheme 96). Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in starter signal wire and electrical connectors between STA terminal at Engine Control Module (ECM) and junction connectors J6 and J7. See «ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA)»(ref-63408-S08009379472001020500000) table. See WIRING DIAGRAMS article. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. Junction connectors J6 and J7 are located behind driver's side of instrument panel, near fuse/relay box and may also be referred to as junction connectors J7 and J8 when referring to wiring diagram. (Scheme 92) For ECM electrical connector terminal identification (Scheme 105)
4. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 105) Using voltmeter, check voltage between body ground and STA terminal at ECM with ignition switch in START position and engine cranking. See «ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA)»(ref-63408-S08009379472001020500000) table. This is the starter signal wire. ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA) Application ECM Connector No. ECM Terminal No. & Wire Color Camry E7 (1) 7 (Gray Or Black/Orange) Camry Solara E7 7 (Gray) (1) Gray wire is used on Toyota Motor Corporation (TMC) vehicles and Black/Orange wire is used on Toyota Motor Manufacturing Kentucky (TMMK) vehicles.
6. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
7. Check for open and short in starter signal wire and electrical connectors between STA terminal at ECM and junction connectors J6 and J7. See WIRING DIAGRAM article. Junction connectors J6 and J7 are located behind driver's side of instrument panel, near fuse/relay box and may also be referred to as junction connectors J7 and J8 when referring to wiring diagram. (Scheme 92)
8. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 97) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in White/Red wire between starter relay and starter fuse, defective starter fuse, and for open and short in Blue wire and electrical connectors between starter fuse and terminal No. 7 at Engine Control Module (ECM) electrical connector E5. This is the starter signal circuit between starter relay and ECM. See WIRING DIAGRAMS article. Starter relay and starter fuse are located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. For ECM electrical connector terminal identification (Scheme 106)
4. If starter fuse, wiring harness or electrical connector is defective, replace fuse or repair wiring harness or electrical connector as necessary. If starter fuse, wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 106)
6. Using voltmeter, check voltage between body ground and terminal No. 7 (Blue wire) at ECM electrical connector E5 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
7. Check for open and short in White/Red wire between starter relay and starter fuse, defective starter fuse, and for open and short in Blue wire and electrical connectors between starter fuse and terminal No. 7 at ECM electrical connector E5. This is the starter signal circuit between starter relay and ECM. See WIRING DIAGRAMS article. Starter relay and starter fuse are located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower.
8. If starter fuse, wiring harness or electrical connector is defective, replace fuse or repair wiring harness or electrical connector as necessary. If starter fuse, wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 98) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Black/Red wire and electrical connectors between terminal No. 7 at Engine Control Module (ECM) electrical connector E8 and starter relay. See WIRING DIAGRAMS article. For ECM electrical connector terminal identification (Scheme 107) Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery.
4. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 107)
6. Using voltmeter, check voltage between body ground and terminal No. 7 (Black/Red wire) at ECM electrical connector E8 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
7. Check for open and short in Black/Red wire and electrical connectors between terminal No. 7 at ECM electrical connector E8 and starter relay. See WIRING DIAGRAMS article. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery.
8. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 99) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Black/White wire and electrical connectors between starter relay and starter fuse, defective starter fuse, and for open and short in Black wire and electrical connectors between starter fuse and terminal No. 7 at Engine Control Module (ECM) electrical connector E5. This is the starter signal circuit between starter relay and ECM. See WIRING DIAGRAMS article. Starter relay and starter fuse are located in fuse/relay box at driver's side front corner of engine compartment, next to battery. Starter relay may be marked as ST relay and starter fuse may be marked as STA fuse. ECM is located behind glove box and heater duct. For illustration of ECM location, see THEORY & OPERATION article. For ECM electrical connector terminal identification (Scheme 108)
4. If starter fuse, wiring harness or electrical connector is defective, replace fuse or repair wiring harness or electrical connector as necessary. If starter fuse, wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove glove box and heater duct for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 108)
6. Using voltmeter, check voltage between body ground and terminal No. 7 (Black wire) at ECM electrical connector E5 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
7. Check for open and short in Black/White wire and electrical connectors between starter relay and starter fuse, defective starter fuse, and for open and short in Black wire and electrical connectors between starter fuse and terminal No. 7 at ECM electrical connector E5. See WIRING DIAGRAMS article. Starter relay and starter fuse are located in fuse/relay box at driver's side front corner of engine compartment, next to battery. Starter relay may be marked as ST relay and starter fuse may be marked as STA fuse.
8. If starter fuse, wiring harness or electrical connector is defective, replace fuse or repair wiring harness or electrical connector as necessary. If starter fuse, wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester, is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 100) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Gray wire and electrical connectors between terminal No. 7 at Engine Control Module (ECM) electrical connector E8 and park/neutral position switch. See WIRING DIAGRAMS article. This is the STA terminal at ECM. ECM is located behind glove box, just above passenger's side lower instrument panel cover. For illustration of ECM location, see THEORY & OPERATION article. Park/neutral position switch is located on side of transaxle. For ECM electrical connector terminal identification (Scheme 109)
4. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove passenger's side lower instrument panel cover for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 109) Using voltmeter, check voltage between body ground and terminal No. 7 (Gray wire) at ECM electrical connector E8 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
6. Check for open and short in Gray wire and electrical connectors between terminal No. 7 at ECM electrical connector E8 and park/neutral position switch. See WIRING DIAGRAMS article. Park/neutral position switch is located on side of transaxle.
7. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 101) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Black/White wire and electrical connectors between terminal No. 7 at Engine Control Module (ECM) electrical connector E5 and park/neutral position switch (A/T models) or clutch start switch (M/T models). See WIRING DIAGRAMS article. This is the STA terminal at ECM. Park/neutral position switch is located on side of transmission. Clutch start switch is located near top of clutch pedal. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. For ECM electrical connector terminal identification (Scheme 110)
4. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
5. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 110)
6. Using voltmeter, check voltage between body ground and terminal No. 7 (Black/White wire) at ECM electrical connector E5 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
7. Check for open and short in Black/White wire and electrical connectors between terminal No. 7 at ECM electrical connector E5 and park/neutral position switch (A/T models) or clutch start switch (M/T models). See WIRING DIAGRAMS article. Park/neutral position switch is located on side of transmission. Clutch start switch is located near top of clutch pedal.
8. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.

Tundra

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 102) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Black/White wire and electrical connectors between starter relay and starter fuse, defective starter fuse, and for open and short in Black wire and electrical connectors between starter fuse and terminal No. 7 at Engine Control Module (ECM) electrical connector E3 on V6 models or electrical connector E4 on V8 models. This is the starter signal circuit between starter relay and ECM. See WIRING DIAGRAMS article. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, next to battery. Starter fuse is located in fuse box behind driver's side of instrument panel. Starter fuse may be marked as STA fuse. ECM is located behind glove box and heater duct. For illustration of ECM location, see THEORY & OPERATION article. For ECM electrical connector terminal identification (Scheme 111)and (Scheme 112).
4. If starter fuse, wiring harness or electrical connector is defective, replace fuse or repair wiring harness or electrical connector as necessary. If starter fuse, wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
5. Remove glove box and heater duct for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 111)and (Scheme 112).
6. Using voltmeter, check voltage between body ground and terminal No. 7 (Black wire) at ECM electrical connector E3 on V6 models or electrical connector E4 on V8 models with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
7. Check for open and short in Black/White wire and electrical connectors between starter relay and starter fuse, defective starter fuse, and for open and short in Black wire and electrical connectors between starter fuse and terminal No. 7 at ECM electrical connector E3 on V6 models or electrical connector E4 on V8 models. See WIRING DIAGRAMS article. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, next to battery. Starter fuse is located in fuse box behind driver's side of instrument panel. Starter fuse may be marked as STA fuse.
8. If starter fuse, wiring harness or electrical connector is defective, replace fuse or repair wiring harness or electrical connector as necessary. If starter fuse, wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.

Scheme 93

Scheme 94

Scheme 95

Scheme 96

Scheme 97

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

Scheme 103

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 5.
2. Connect hand-held tester to data link connector No. 3. (Scheme 103) Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on and with ignition switch in START position and engine cranking. The STA signal display should read OFF with ignition on and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Check for open and short in Black/White wire and electrical connectors between Engine Control Module (ECM) terminal No. 7 at ECM electrical connector E14 and splice I21. See WIRING DIAGRAMS article. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. For identification of ECM electrical connector terminals (Scheme 113) Splice I21 is located at passenger's side of instrument panel. (Scheme 93)
4. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
5. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 113) Using voltmeter, check voltage between body ground and terminal No. 7 (Black/White wire) at ECM electrical connector E14 with ignition switch in START position and engine cranking. This is the STA terminal at ECM. Voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
6. Check for open and short in Black/White wire and electrical connectors between terminal No. 7 at ECM electrical connector E14 and splice I21. See WIRING DIAGRAMS article. Splice I21 is located at passenger's side of instrument panel. (Scheme 93)
7. If wiring harness or electrical connector are defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

Power & Ground Circuits

For testing of Engine Control Module (ECM) power and ground circuits, see ENGINE CONTROL MODULE POWER SOURCE CIRCUIT. Also see PIN VOLTAGE CHARTS article. For illustration of ECM location, see THEORY & OPERATION article. For identification of ECM electrical connector terminals (Scheme 104)- (Scheme 113).

Scheme 104

Scheme 105

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

Scheme 111

Scheme 112

Scheme 113

For testing of accelerator pedal position sensor, see THROTTLE BODY under IDLE CONTROL SYSTEMS.

AIR/FUEL (A/F) SENSOR

Note. Air/Fuel (A/F) sensor may also be referred to as Air/Fuel (A/F) ratio sensor.

Avalon, Camry With A/T, Camry Solara With A/T, Highlander & Sienna

1. Two heated A/F sensors are used, one on each exhaust manifold. Heated A/F sensor on rear (firewall side) exhaust manifold may also be referred to as bank No. 1 sensor No. 1. Heated A/F sensor on front (radiator side) exhaust manifold may also be referred to as bank No. 2 sensor No. 1.
2. If problem exists in A/F sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
3. To test heater resistance on A/F sensor, disconnect electrical connector at A/F sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 114)- (Scheme 116). Replace A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C) and 1.8-3.2 ohms at 1472°F (800°C).

Scheme 114

Scheme 115

Scheme 116

1. Heated A/F sensor is located on exhaust pipe in front of catalytic converter. Heated A/F sensor may also be referred to as bank No. 1 sensor No. 1. If problem exists in A/F sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
2. To test heater resistance on A/F sensor, disconnect electrical connector at A/F sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 117) Replace A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C) and 1.8-3.2 ohms at 1472°F (800°C).

Scheme 117

AIRFLOW METER

Note. Airflow meter may also be referred to as Mass Airflow (MAF) meter.

Scheme 118

Scheme 119

1. Ensure ignition is off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to top side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter and note airflow meter terminal identification. (Scheme 118)
2. Using ohmmeter, check resistance between terminals E2 and THA on airflow meter. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-63408-S04996508182001020500000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. (Scheme 119)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 119) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter.

Scheme 120

Scheme 121

1. Ensure ignition is off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter with gasket and note airflow meter terminal identification. (Scheme 120)
2. Using ohmmeter, check resistance between terminals E2 and THA on airflow meter. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-63408-S04996508182001020500000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. (Scheme 121)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 121) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter using NEW gasket.

Scheme 122

Scheme 123

Scheme 124

1. Turn ignition off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to top side of air intake hose, near upper cap on air cleaner assembly. Remove airflow meter and note airflow meter terminal identification. (Scheme 122)and. (Scheme 123).
2. Using ohmmeter, check resistance between terminals E2 and THA on airflow meter. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-63408-S04996508182001020500000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. (Scheme 122)and (Scheme 124).
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 122)and (Scheme 124). While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter.

Scheme 125

1. Ensure ignition is off. Disconnect electrical connector at airflow meter. Airflow meter is bolted to air intake hose, near air cleaner assembly. Remove airflow meter with "O" ring (if equipped) and note airflow meter terminal identification. (Scheme 118)
2. Using ohmmeter, check resistance between terminals E2 and THA on airflow meter. Resistance should be within specification in relation to the temperature. See «AIRFLOW METER RESISTANCE»(ref-63408-S04996508182001020500000) table. Replace airflow meter if resistance is not within specification.
3. To test airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. (Scheme 125)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 125) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter. Reinstall airflow meter using NEW "O" ring (if equipped).

AIRFLOW METER RESISTANCE

BRAKELIGHT SWITCH

Note. Brakelight switch may also be referred to as stoplight switch.

Scheme 126

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of the brake pedal. Note terminal identification on brakelight switch. (Scheme 126)
2. On models without cruise control, using ohmmeter, check that no continuity exists between terminals No. 1 and 2 with brake pedal released so pin on brakelight switch is pushed in. Check that continuity exists between terminals No. 1 and 2 with brake pedal depressed so pin on brakelight switch is extended. Adjust or replace brakelight switch if operation is not as described.
3. On models with cruise control, using ohmmeter, check that no continuity exists between terminals No. 1 and 2 with brake pedal released so pin on brakelight switch is pushed in. Check that continuity exists between terminals No. 1 and 2 with brake pedal depressed so pin on brakelight switch is extended.
4. Check that no continuity exists between terminals No. 3 and 4 with brake pedal depressed so pin on brakelight switch is extended. Check that continuity exists between terminals No. 3 and 4 with brake pedal released so pin on brakelight switch is pushed in. Adjust or replace brakelight switch if operation is not as described.

Scheme 127

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on the brakelight switch. (Scheme 127)
2. Using ohmmeter, check that continuity exists between terminals No. 1 and 2 with brake pedal depressed so pin on brakelight switch is extended. Check that no continuity exists between terminals No. 1 and 2 with brake pedal released so pin on brakelight switch is pushed in.
3. Check that no continuity exists between terminals No. 3 and 4 with brake pedal depressed so pin on brakelight switch is extended. Check that continuity exists between terminals No. 3 and 4 with brake pedal released so pin on brakelight switch is pushed in. Adjust or replace brakelight switch if operation is not as described.

Scheme 128

1. Disconnect electrical connector for brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on electrical connector for brakelight switch. (Scheme 128)
2. Using ohmmeter, check that continuity exists between terminals No. 1 and 4 with brake pedal depressed so pin on brakelight switch is extended. Check that no continuity exists between terminals No. 1 and 4 with brake pedal released so pin on brakelight switch is pushed in.
3. Check that no continuity exists between terminals No. 2 and 3 with brake pedal depressed so pin on brakelight switch is extended. Check that continuity exists between terminals No. 2 and 3 with brake pedal released so pin on brakelight switch is pushed in. Adjust or replace brakelight switch if operation is not as described.

CAMSHAFT POSITION SENSOR

For testing camshaft position sensor, see CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

CRANKSHAFT POSITION SENSOR

For testing crankshaft position sensor, see CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Camry & Camry Solara

1. Manufacturer recommends removing throttle body for access to EGR gas temperature sensor. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. Remove EGR gas temperature sensor. EGR gas temperature sensor is screwed into bottom of pipe that EGR valve is mounted on.
2. Place threaded end of EGR gas temperature sensor and thermometer in container of oil. Attach ohmmeter between electrical terminals on EGR gas temperature sensor.
3. Heat oil and note resistance at specified temperature. See «EGR GAS TEMPERATURE SENSOR RESISTANCE»(ref-63408-S09854675182001020500000) table. Replace EGR gas temperature sensor if resistance is not within specification. Reinstall EGR gas temperature sensor. EGR GAS TEMPERATURE SENSOR RESISTANCE Temperature Ohms 122°F (50°C) 64,000-97,000 212°F (100°C) 11,000-16,000 302°F (150°C) 2000-4000

For testing of EGR position sensor, see EGR POSITION SENSOR under EMISSION SYSTEMS & SUB-SYSTEMS.

Avalon, Camry, Camry Solara, Highlander & Sienna

1. Ensure ignition is off. Note location of Engine Coolant Temperature (ECT) sensor. See «ENGINE COOLANT TEMPERATURE SENSOR LOCATION»(ref-63408-S28081524292001020500000) table. Remove ECT sensor. See ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 129) Replace ECT sensor if resistance is not within specification. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Fill cooling system.

Land Cruiser, Sequoia & Tundra 4.7L V8

1. Note location of Engine Coolant Temperature (ECT) sensor. See «ENGINE COOLANT TEMPERATURE SENSOR LOCATION»(ref-63408-S28081524292001020500000) table. Manufacturer recommends removing throttle body for access to ECT sensor. Remove ECT sensor. See ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 129) Replace ECT sensor if resistance is not within specification. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Install throttle body. Fill cooling system.

1. Note location of Engine Coolant Temperature (ECT) sensor. See «ENGINE COOLANT TEMPERATURE SENSOR LOCATION»(ref-63408-S28081524292001020500000) table. Manufacturer recommends removing upper timing belt cover and fuel crossover pipe for access to ECT sensor. Remove ECT sensor. See ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 129) Replace ECT sensor if resistance is not within specification. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Fill cooling system.

ENGINE COOLANT TEMPERATURE SENSOR LOCATION

Scheme 129

For testing of fuel pump switch, see FUEL PUMP SWITCH under FUEL DELIVERY under FUEL SYSTEMS.

Scheme 130

1. A heated Air/Fuel (A/F) sensor is used on each exhaust manifold and heated oxygen sensor is used on exhaust pipe behind catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63408-S29411026202001020500000). Heated oxygen sensor on exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2.
2. To test heater on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 130) Electrical connector for heated oxygen sensor is located below passenger's side front seat, near center console and contains a Dark Gray 4-pin electrical connector. It is necessary to remove passenger's seat. Pull back carpeting to access connector.
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 130) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

1. On A/T models, a heated Air/Fuel (A/F) sensor is used on each exhaust manifold and a heated oxygen sensor is used on exhaust pipe behind catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63408-S29411026202001020500000). Heated oxygen sensor on the exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2.
2. On M/T models, a heated oxygen sensor is used on each exhaust manifold and on exhaust pipe behind catalytic converter. Heated oxygen sensor on rear (firewall side) exhaust manifold may also be referred to as bank No. 1 sensor No. 1. Heated oxygen sensor on front (radiator side) exhaust manifold may also be referred to as bank No. 2 sensor No. 1. Heated oxygen sensor on the exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2.
3. On all applications, to test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 131)and (Scheme 132). Electrical connector for heated oxygen sensor on exhaust pipe behind catalytic converter is located below driver's side front seat, below carpet near center console and contains a Dark Gray 4-pin electrical connector.
4. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 131)and (Scheme 132). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C).
5. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 131

Scheme 132

Scheme 133

1. A heated Air/Fuel (A/F) sensor is used on each exhaust manifold and a heated oxygen sensor is used on exhaust pipe behind catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63408-S29411026202001020500000). Heated oxygen sensor on exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2.
2. To test heater on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 133)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 130) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 134

1. Four heated oxygen sensors are used, one on each exhaust manifold and one on each exhaust pipe behind catalytic converter. On driver's side, heated oxygen sensor on exhaust manifold may also be referred to as bank No. 1 sensor No. 1 and heated oxygen sensor on exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2. On passenger's side, heated oxygen sensor on exhaust manifold may also be referred to as bank No. 2 sensor No. 1 and heated oxygen sensor on exhaust pipe behind catalytic converter may also be referred to as bank No. 2 sensor No. 2.
2. To test heater on heated oxygen sensor, disconnect electrical connector at appropriate heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 134)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 134) On Land Cruiser and Sequoia, replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C). On Tundra 4.7L V8, replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C).
4. On all models, if problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 135

1. A heated Air/Fuel (A/F) sensor is used on each exhaust manifold and a heated oxygen sensor is used on exhaust pipe behind catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63408-S29411026202001020500000). Heated oxygen sensor on exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2.
2. To test heater on heated oxygen sensor, disconnect electrical connector at heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 135) Electrical connector for heated oxygen sensor is located below passenger's side front seat, underneath the carpet and contains a Dark Gray 4-pin electrical connector.
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 135) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

1. A heated Air/Fuel (A/F) sensor is used on exhaust pipe in front of catalytic converter and a heated oxygen sensor is used on exhaust pipe behind catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63408-S29411026202001020500000). Heated oxygen sensor exhaust pipe behind catalytic converter may also be referred to as bank No. 1 sensor No. 2.
2. To test heater on heated oxygen sensor, disconnect electrical connector at heated oxygen sensor and note heated oxygen sensor terminals. (Scheme 136)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 136) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C).
4. If problem exists in heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 136

Avalon, Camry, Camry Solara, Highlander, Sienna, Tacoma, Tundra 3.4L V6 & 4Runner

1. Knock sensors No. 1 and 2 are located below intake manifold on cylinder block. (Scheme 137)and (Scheme 138). Manufacturer lists testing procedure with knock sensor removed from cylinder block before testing. Remove knock sensor. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
2. Using ohmmeter, check that no continuity exists between electrical terminal on knock sensor and body of knock sensor. Replace knock sensor if continuity exists.

Scheme 137

Scheme 138

1. Knock sensors No. 1 and 2 are located below intake manifold on cylinder block. (Scheme 139) Remove intake manifolds for access to knock sensor. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article for removal of intake manifolds.
2. Disconnect electrical connector at knock sensor. Using ohmmeter, check that no continuity exists between electrical terminal on knock sensor and body of knock sensor. Replace knock sensor if continuity exists.

Scheme 139

A/T Models

1. Disconnect electrical connector at Park/Neutral Position (PNP) switch. PNP switch is mounted on side of transmission/transaxle. Note terminal identification. (Scheme 140)and (Scheme 141).
2. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(ref-63408-S02883603842001020500000) table. If proper continuity cannot obtained, adjust or replace PNP switch as necessary. For adjustment of PNP switch, see PARK/NEUTRAL POSITION SWITCH under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 140

Scheme 141

Power steering pressure switch is located on power steering pump, near pressure hose. Testing information is not available from manufacturer.

Avalon, Camry, Camry Solara, Highlander, Sienna, Tacoma & Tundra 3.4L V6

1. Ensure ignition is off. Disconnect electrical connector at Throttle Position (TP) sensor mounted on side of throttle body. Note terminal identification on TP sensor. (Scheme 142)- (Scheme 146).
2. On Avalon, Camry, Camry Solara, Sienna, Tacoma and Tundra, apply vacuum to throttle opener. On all models, using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-63408-S27465965742001020500000) table. Replace components as necessary if resistance is not within specification.

THROTTLE POSITION SENSOR RESISTANCE

Scheme 142

Scheme 143

Scheme 144

Scheme 145

Scheme 146

For testing of throttle position sensor, see THROTTLE BODY under IDLE CONTROL SYSTEMS.

VAPOR PRESSURE SENSOR

For testing of vapor pressure sensor, see VAPOR PRESSURE SENSOR under FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS.

Avalon, Highlander & Sienna

Variable Valve Timing (VVT) sensor may also be referred to as camshaft position sensor. For testing of VVT sensor, see CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Wheel speed sensors on each wheel deliver an input signal to Anti-Lock Brake System (ABS) Electronic Control Unit (ECU). ABS ECU converts input signals from wheel speed sensors to a 4-pulse input signal to the instrument cluster. Instrument cluster then converts 4-pulse input signal to a rectangular waveform and then sends vehicle speed signal to Engine Control Module (ECM). On models with traction control, ABS ECU may also be referred to as ABS & BA (Brake Assist) & TRAC & Vehicle Skid Control (VSC) ECU. On models without traction control, ABS ECU may also be referred to as ABS actuator and ECU. On all applications, if problem exists with vehicle speed signal, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

1. Vehicle speed sensor is located on transaxle. (Scheme 147) Remove vehicle speed sensor. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 148)
2. Using jumper wires, connect positive battery terminal to terminal No. 1 (outer terminal) and negative battery terminal to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 148)
3. While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts to at least 11 volts. Voltage should change 4 times per revolution of the shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

Scheme 147

Scheme 148

Wheel speed sensors on each wheel deliver an input signal to skid control Electronic Control Unit (ECU). Skid control ECU converts input signals from wheel speed sensors to a 4-pulse input signal to the instrument cluster. Instrument cluster then converts 4-pulse input signal to a rectangular waveform and then sends vehicle speed signal to Engine Control Module (ECM). If problem exists with vehicle speed signal, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Vehicle speed sensor is located on transmission. (Scheme 149) Testing information is not available from manufacturer. If problem exists with vehicle speed sensor, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 149

1. Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a Black 3-pin electrical connector with Yellow, Yellow/Red and Red/Blue wires. Remove vehicle speed sensor. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 148)
2. Using jumper wires, connect positive battery terminal to terminal No. 1 (outer terminal) and negative battery terminal to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 148)
3. While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts to at least 11 volts. Voltage should change 4 times per revolution of the shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

Wheel speed sensors on each wheel deliver an input signal to Anti-Lock Brake System (ABS) Electronic Control Unit (ECU). ABS ECU converts input signals from wheel speed sensors to a 4-pulse input signal to the instrument cluster. Instrument cluster then converts 4-pulse input signal to a rectangular waveform and then sends vehicle speed signal to Engine Control Module (ECM). On models with Vehicle Skid Control (VSC), ABS ECU may also be referred to as VSC ECU. On models without VSC, ABS ECU may also be referred to as ABS actuator and ECU. On all applications, if problem exists with vehicle speed signal, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 150

Scheme 151

Scheme 152

1. Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a Black 3-pin electrical connector with Blue, Green/Red and Pink wires. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 150)- (Scheme 152).
2. Using jumper wires, connect positive battery terminal to terminal No. 1 (outer terminal) and negative battery terminal to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 150)- (Scheme 152).
3. While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts to at least 11 volts. Voltage should change 4 times per revolution of the shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

1. Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a Black 3-pin electrical connector with Blue/Yellow, Black/Yellow and Pink/Blue wires. Remove vehicle speed sensor. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 148)
2. Using jumper wires, connect positive battery terminal to terminal No. 1 (outer terminal) and negative battery terminal to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 148)
3. While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts to at least 11 volts. Voltage should change 4 times per revolution of the shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

Wheel speed sensors on each wheel deliver an input signal to Vehicle Skid Control (VSC) Electronic Control Unit (ECU). VSC ECU converts input signals from wheel speed sensors to a 4-pulse input signal to the instrument cluster. Instrument cluster then converts 4-pulse input signal to a rectangular waveform and then sends vehicle speed signal to Engine Control Module (ECM). If problem exists with vehicle speed signal, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

See FUEL PUMP ELECTRONIC CONTROL UNIT under FUEL DELIVERY under FUEL SYSTEMS.

A/F HEATER RELAY

Note. A/F heater relay may also be referred to as A/F HTR relay, A/F sensor relay or A/F relay.

Scheme 153

Scheme 154

Scheme 155

1. Remove A/F heater relay. See «A/F HEATER RELAY LOCATION»(ref-63408-S41381121092001020500000) table. A/F HEATER RELAY LOCATION Application Location Avalon In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, Near Battery Camry & Camry Solara In Small Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, In Front Of Battery Highlander In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, Just In Front Of Strut Tower Sienna (1) (1) Located near Engine Control Module (ECM) behind passenger's side of instrument panel. (Scheme 153)
2. To test A/F heater relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on A/F heater relay. (Scheme 154)and (Scheme 155).
3. To test A/F heater relay operation, apply battery voltage and ground to A/F heater relay and use ohmmeter to check for continuity between specified terminals on A/F heater relay. (Scheme 154)and (Scheme 155). Replace A/F heater relay if defective.

CIRCUIT OPENING RELAY

Note. Circuit opening relay is used on all models except Land Cruiser.

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(ref-63408-S05336334232001020500000) table. (Scheme 156)- (Scheme 164). CIRCUIT OPENING RELAY LOCATION (1) Application Location Avalon Top Corner Of Relay Box Behind Driver's Side Kick Panel Camry & Camry Solara In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, Near Battery Highlander In Relay Box Just Above Driver's Side Kick Panel Sequoia, Sienna & Tundra In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, Near Battery Tacoma Behind Lower Instrument Panel Cover, Next To Driver's Side Of Steering Column 4Runner Below Right Corner Of Fuse/Relay Box Behind Lower Instrument Panel Cover At Driver's Side Of Instrument Panel To Left Of Steering Column, Just Above Hood Release Lever (1) Circuit opening relay may be marked as CIR OPN relay.
2. To test circuit opening relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on circuit opening relay. see scheme 85- (Scheme 167).
3. To test circuit opening relay operation, apply battery voltage and ground to circuit opening relay and use ohmmeter to check for continuity between specified terminals on circuit opening relay. see scheme 85- (Scheme 167). Replace circuit opening relay if defective.

Scheme 156

Scheme 157

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

EFI MAIN RELAY

Note. EFI main relay is used on all models and may also be referred to as EFI relay.

1. Ensure ignition is off. Remove EFI main relay from fuse/relay box at driver's side front corner of engine compartment, near battery.
2. To test EFI main relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on EFI main relay. see scheme 85- (Scheme 168).
3. To test EFI main relay operation, apply battery voltage and ground to EFI main relay and use ohmmeter to check for continuity between specified terminals on EFI main relay. see scheme 85- (Scheme 168). Replace EFI main relay if defective.

Scheme 168

Sequoia & Tundra 4.7L V8

1. Ensure ignition is off. Remove fuel pump relay from fuse/relay box at driver's side front corner of engine compartment, next to battery. (Scheme 159)- (Scheme 163).
2. To test fuel pump relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on fuel pump relay. (Scheme 169)
3. To test fuel pump relay operation, apply battery voltage and ground to fuel pump relay and use ohmmeter to check for continuity between specified terminals on fuel pump relay. (Scheme 169) Replace fuel pump relay if defective.

Scheme 169

IG2 RELAY

Note. IG2 relay may also be referred to as ignition relay.

1. Ensure ignition is off. Remove IG2 relay from fuse/relay box at driver's side front corner of engine compartment, next to battery.
2. To test IG2 relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on IG2 relay. see scheme 91
3. To test IG2 relay operation, apply battery voltage and ground to IG2 relay and use ohmmeter to check for continuity between specified terminals on IG2 relay. see scheme 91 Replace IG2 relay if defective.

For testing of throttle control motor, see THROTTLE BODY under IDLE CONTROL SYSTEMS.

FUEL SYSTEM PRESSURE RELEASE

For fuel system pressure release procedures, see FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.

See CIRCUIT OPENING RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS.

See EFI MAIN RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS.

Fuel Pump Electronic Control Unit (Land Cruiser)

Fuel pump Electronic Control Unit (ECU) is located behind inner panel, just behind driver's side rear wheelwell. (Scheme 170) Testing information is not available from manufacturer. If problem exists with fuel pump ECU or wiring circuit, a Diagnostic Trouble Code (DTC) P1200 may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Scheme 170

Fuel Pump Pressure

For fuel pump pressure testing, see FUEL PRESSURE under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Fuel Pump Relay (Sequoia & Tundra 4.7L V8)

See FUEL PUMP RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS.

Scheme 171

1. Fuel pump resistor is located at driver's side front corner of engine compartment, near end of fuse/relay box. (Scheme 171) Manufacturer lists testing procedure with fuel pump resistor removed. Disconnect electrical connector at fuel pump resistor.
2. Remove bolt and fuel pump resistor. Using ohmmeter, check resistance between electrical terminals on fuel pump resistor. Replace fuel pump resistor if resistance is not.70-.76 ohms at 68°F (20°C). Reinstall fuel pump resistor.

Fuel Pump Switch (Land Cruiser)

Note. Fuel pump switch may also be referred to as fuel pump inertia switch or fuel pump control switch.

Scheme 172

1. Fuel pump switch is located on driver's side of instrument panel and contains a reset switch. (Scheme 172) Disconnect electrical connector at fuel pump switch. It may be necessary to remove carpet and fuel pump switch for access to electrical connector.
2. Using ohmmeter, check that no continuity exists between electrical terminals on fuel pump switch with reset switch in OFF position. Check that continuity exists between electrical terminals on fuel pump switch with reset switch in ON position. Replace fuel pump switch if defective. Ensure reset switch is in the ON position for fuel pump operation.

Fuel Cut System (Avalon, Camry, Camry Solara, Land Cruiser, Sequoia, Sienna, Tacoma, Tundra & 4Runner)

1. On Avalon, Camry, Camry Solara and Sienna, remove "V" bank cover on top of engine for access to fuel injectors. (Scheme 85), (Scheme 86).
2. On all models, connect Toyota hand-held tester or scan tool to data link connector No. 3. (Scheme 94)- (Scheme 103). Hand-held tester or scan tool is used to read engine RPM. Start engine. Warm engine to normal operating temperature.
3. Ensure A/C is off. Gradually increase engine speed to specified RPM. See «FUEL CUT SYSTEM TESTING SPEED»(ref-63408-S23977339822001020500000) table. FUEL CUT SYSTEM TESTING SPEED Application Engine RPM Avalon, Camry, Camry Solara, Sienna, Tacoma, Tundra 3.4L V6 & 4Runner 3500 Land Cruiser, Sequoia & Tundra 4.7L V8 2500
4. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily and then resumes operating (fuel return RPM).
5. Ensure fuel return RPM is within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(ref-63408-S34470017442001020500000) table. Shut engine off. Remove hand-held tester or scan tool.

FUEL CUT SYSTEM SPECIFICATIONS (1)

Fuel Cut System (Highlander)

1. Remove "V" bank cover on top of engine for access to fuel injectors. (Scheme 85) Connect Toyota hand-held tester or scan tool to data link connector No. 3. (Scheme 97) Hand-held tester or scan tool is used to read engine RPM. Start engine. Warm engine to normal operating temperature.
2. Ensure A/C is off. Gradually increase engine speed to 3500 RPM. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily and then resumes operating. Shut engine off. Remove hand-held tester or scan tool.

Avalon & Sienna

1. Start engine. Warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 article. Turn ignition off. Apply parking brake and place transaxle in Neutral. Ensure A/C is off.
2. On Avalon, install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 178) Data link connector No. 1 is located in the engine compartment on end of air intake chamber at passenger's side of engine. Go to step 4.
3. On Sienna, install Jumper Wire (SST 09843-18020) between terminals TC and E1 on data link connector No. 1. (Scheme 181) Data link connector No. 1 on engine mount bracket at passenger's side front of engine. Go to next step.
4. On all models, start engine and note engine speed. Engine speed should increase to 1000 RPM for 5 seconds and then return to idle speed. If engine speed is not as specified, test Idle Air Control (IAC) valve operation. Go to next step. If engine speed is as specified, remove jumper wire. Turn ignition off.
5. To test IAC valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. Check that valve on inside of IAC valve is half open. (Scheme 184) Reinstall electrical connector on IAC valve.
6. Turn ignition on. Check that valve on inside of IAC valve moves from half open to fully closed, fully open and then returns to half open within.5 seconds.
7. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. If IAC valve operates properly but idle problem still exists, the air assist system may be defective. For testing of air assist system, see «AIR ASSIST SYSTEM»(ref-63408-S26713604892001020500000). If IAC valve does not operate, check wiring circuit between ECM and IAC valve. See «ECM LOCATION»(ref-63408-S10139236482001020500000) table. See WIRING DIAGRAMS article. If wiring circuit and ECM are okay, replace IAC valve.

Camry, Camry Solara, Tacoma & Tundra 3.4L V6

1. Start engine. Warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 article.
2. Turn ignition off. Apply parking brake and place transmission/transaxle in Neutral. Ensure A/C is off. On Camry, Camry Solara and Tacoma, go to next step. On Tundra, go to step 4.
3. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1 located in the engine compartment. (Scheme 179), (Scheme 180) and (Scheme 182). See «DATA LINK CONNECTOR NO. 1 LOCATION»(ref-63408-S05715628202001020500000) table. Go to step 5. DATA LINK CONNECTOR NO. 1 LOCATION Application Location Camry On End Of Air Intake Chamber At Passenger's Side Of Engine Camry Solara Passenger's Side Of Engine Compartment, Near Strut Tower Tacoma Center Of Air Intake Chamber At Driver's Side Of Engine
4. Note location of data link connector No. 3 at driver's side of instrument panel. (Scheme 102) Install Jumper Wire (SST 09843-18040) between terminals No. 4 (CG) and 13 (TC) on data link connector No. 3. (Scheme 183) Go to next step.
5. On all models, start engine and note engine speed. On Camry, Camry Solara and Tacoma, engine speed should increase to 1000 RPM for 5 seconds and then return to idle speed. On Tundra, engine speed should increase to 900-1500 RPM for 5 seconds and then return to idle speed. On all models, if engine speed is not as specified, test IAC valve resistance and IAC valve operation. Go to next step. If engine speed is as specified, remove jumper wire. Turn ignition off.
6. To test IAC valve resistance, ensure ignition is off. Disconnect electrical connector at IAC valve. IAC valve is located on lower area of throttle body. Using ohmmeter, checking resistance between +B terminal and each remaining terminal on IAC valve. (Scheme 185)- (Scheme 186).
7. Replace IAC valve if resistance is not within specification. See «IAC VALVE RESISTANCE»(ref-63408-S21689707332001020500000) table. IAC VALVE RESISTANCE Application Ohms Camry Cold (1) 17.0-25.0 Hot (2) 21.5-29.5 Camry Solara Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 Tacoma & Tundra Cold (1) 17.0-25.0 Hot (2) 21.5-29.5 (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C).
8. To test IAC valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. Apply battery voltage to +B terminal on IAC valve. Apply battery ground to proper terminal and ensure valve opens and closes. (Scheme 187)and (Scheme 188). Replace IAC valve if defective.
9. If IAC valve resistance is within specification and operates properly, check wiring circuit between Engine Control Module (ECM) and IAC valve. See «ECM LOCATION»(ref-63408-S10139236482001020500000) table. See WIRING DIAGRAMS article. If all components and wiring circuit are okay, but idle problem still exists, the air assist system may be defective. For testing of air assist system, see «AIR ASSIST SYSTEM»(ref-63408-S26713604892001020500000).

ECM LOCATION

Scheme 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178

Scheme 179

Scheme 180

Scheme 181

Scheme 182

Scheme 183

1. If problem exists in Idle Air Control (IAC) valve or wiring circuit, a Diagnostic Trouble Code (DTC) P0505 may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
2. To test IAC operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Reinstall electrical connector on IAC valve.
3. Turn ignition on. Check that valve on inside of IAC valve moves from half open to fully closed, fully open and then returns to half open within.5 seconds. (Scheme 184)
4. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. Clear any stored DTCs from ECM after checking IAC valve operation. If IAC valve does not operate, check wiring circuit between ECM and IAC valve. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. See WIRING DIAGRAMS article. If wiring circuit and ECM are okay, replace IAC valve.

Avalon, Camry, Camry Solara, Sienna, Tacoma & Tundra 3.4L V6

1. Start engine. Warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 article.
2. Turn ignition off. Apply parking brake and place transmission/transaxle in Neutral. Ensure A/C is off.
3. On Avalon, Camry, Camry Solara and Tacoma, install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 178)- (Scheme 180) and (Scheme 182). See «DATA LINK CONNECTOR NO. 1 LOCATION»(ref-63408-S29212297922001020500000) table. On Sienna, install Jumper Wire (SST 09843-18020) between terminals TC and E1 on data link connector No. 1. (Scheme 181) See «DATA LINK CONNECTOR NO. 1 LOCATION»(ref-63408-S29212297922001020500000) table. On Tundra, note location of data link connector No. 3 at driver's side of instrument panel. (Scheme 102) Install Jumper Wire (SST 09843-18040) between terminals No. 4 (CG) and 13 (TC) on data link connector No. 3. (Scheme 183) On all models, go to next step. DATA LINK CONNECTOR NO. 1 LOCATION Application Location Avalon & Camry On End Of Air Intake Chamber At Passenger's Side Of Engine Camry Solara Passenger's Side Of Engine Compartment, Near Strut Tower Sienna On Engine Mount Bracket At Passenger's Side Front Of Engine Tacoma Center Of Air Intake Chamber At Driver's Side Of Engine
4. Start engine and note engine speed. After engine speed is kept at 900-1300 RPM for 10 seconds, ensure engine returns to idle speed. Turn ignition off.
5. On Avalon, Camry, Camry Solara and Sienna, disconnect air assist hose from air pipe. (Scheme 189)and (Scheme 190). Air assist hose fits between IAC valve and air pipe. Place plug on end of air pipe and air assist hose. (Scheme 189)and (Scheme 190). Go to step 7.
6. On Tacoma and Tundra, disconnect air assist hose from IAC valve. (Scheme 191) Place plug on end of air assist hose. (Scheme 191) Go to next step.
7. On all models, start engine and note idle speed. Idle speed should be 500 RPM or less which may cause the engine to stall. Turn ignition off.
8. If idle speed is not 500 RPM or less, check for air leak between air assist hoses, air pipe and fuel injectors. Remove plug(s) and jumper wire. Reconnect air assist hose.

Scheme 184

Scheme 185

Scheme 186

Note. Electronic Throttle Control System (ETCS) is used for controlling idle speed. ETCS consists of throttle body, accelerator pedal position sensor, Throttle Position (TP) sensor, throttle control motor, magnetic clutch and Engine Control Module (ECM).

Scheme 187

Scheme 188

Scheme 189

Scheme 190

Scheme 191

Scheme 192

Scheme 193

Scheme 194

Scheme 195

Scheme 196

1. On Land Cruiser, remove intake manifold cover located on top of engine for access to throttle body. On Sequoia and Tundra, remove throttle body cover for access to throttle body. On all models, ensure throttle cable and throttle lever on throttle body moves smoothly. Note location of throttle control motor on throttle body. (Scheme 192)and (Scheme 193).
2. To check throttle control motor operation, turn ignition on. Rotate throttle lever on throttle body to full throttle while listing for operating sound at throttle control motor and check that no grinding noise is heard at throttle control motor and throttle body. Throttle lever will also rotate accelerator pedal position sensor.
3. If throttle control motor operating sound is heard, go to next step. If throttle control motor operating sound is not heard, throttle control motor, wiring harness or Engine Control Motor (ECM) may be defective. On Land Cruiser, ECM is located above glove box, near passenger's side of instrument panel. On Sequoia and Tundra, ECM is located behind glove box and heater duct. On 4Runner, ECM is located behind glove box. On all models, for illustration of ECM location, see THEORY & OPERATION article. Go to step 12 for testing of throttle control motor. For wiring of throttle control motor, see WIRING DIAGRAMS article.
4. To test operation of accelerator pedal position sensor, Toyota hand-held tester may be used or voltmeter may be used. If using Toyota hand-held tester, go to next step. If using voltmeter, go to step 8.
5. Connect hand-held tester to data link connector No. 3. (Scheme 98), (Scheme 99), (Scheme 102) and (Scheme 103). Hand-held tester is used to read throttle valve opening which is displayed as a percentage. Ensure Malfunction Indicator Light (MIL) on instrument panel is not illuminated. If MIL is not illuminated, go to next step. If MIL is illuminated, a Diagnostic Trouble Code (DTC) may be stored in ECM. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
6. Rotate throttle lever on throttle body to full throttle while reading throttle valve opening on hand-held tester which is accessed by THROTTLE POS under CURRENT DATA. Throttle lever will also rotate accelerator pedal position sensor. Throttle valve opening should be at least 60 percent.
7. If throttle valve opening is at least 60 percent, go to step 10. If throttle valve opening is not at least 60 percent, problem may exist in accelerator pedal position sensor, wiring circuit or ECM. Go to step 15 for testing of accelerator pedal position sensor. For wiring of accelerator pedal position sensor, see WIRING DIAGRAMS article.
8. Access Engine Control Module (ECM). On Land Cruiser, ECM is located above glove box, near passenger's side of instrument panel. On Sequoia and Tundra, ECM is located behind glove box and heater duct. On 4Runner, ECM is located behind glove box. On all models, for illustration of ECM location, see THEORY & OPERATION article. On all models, ensure ignition is on. Using voltmeter, check voltage between ECM terminals VPA and E2 with accelerator pedal released and with accelerator pedal fully depressed. (Scheme 194)and (Scheme 195). See «ECM TERMINAL WIRE COLOR IDENTIFICATION»(ref-63408-S27326972192001020500000) table. ECM TERMINAL WIRE COLOR IDENTIFICATION Application & ECM Terminal Wire Color Land Cruiser E2 Brown/White VPA Red Sequoia & Tundra E2 Green/White VPA Green/Red 4Runner E2 Blue/Black VPA Gray
9. Voltage should.3-.9 volt with accelerator pedal released and 3.2-4.8 volts with accelerator pedal fully depressed. If voltage is within specification, go to next step. If voltage is not within specification, problem may exist in accelerator pedal position sensor, wiring circuit or ECM. Go to step 15 for testing of accelerator pedal position sensor. For wiring of accelerator pedal position sensor, see WIRING DIAGRAMS article.
10. Start engine and allow engine to idle. Check operation of Malfunction Indicator Light (MIL) on instrument panel. If MIL is not illuminated, go to next step. If MIL is illuminated, a Diagnostic Trouble Code (DTC) may be stored in ECM. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
11. Allow engine to warm to normal operating temperature. Apply parking brake. Place transmission in Neutral. Ensure A/C is off. Note engine idle speed. Engine idle speed should be 650-750 RPM. If all previous steps have been performed, drive vehicle to verify proper operation of throttle body.
12. To test throttle control motor, disconnect electrical connector at throttle control motor. (Scheme 192)and (Scheme 193). Note terminal identification on throttle control motor. (Scheme 196)and (Scheme 197).
13. Using ohmmeter, check resistance between specified terminals on throttle control motor. See «THROTTLE CONTROL MOTOR RESISTANCE»(ref-63408-S09162383572001020500000) table. If resistance is within specification, reinstall electrical connector. Go to next step. On Land Cruiser, Sequoia and Tundra, if resistance is not within specification, replace throttle control motor. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. On 4Runner, if resistance is not within specification, replace throttle body with throttle control motor as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. THROTTLE CONTROL MOTOR RESISTANCE Terminal No. Ohms @ 68°F (20°C) Land Cruiser, Sequoia & Tundra 1 & 2.3-100.0 3 & 4 4.2-5.2 4Runner 1 & 2 4.2-5.2 3 & 4.3-100.0
14. To test TP sensor, disconnect electrical connector at TP sensor. (Scheme 192)and (Scheme 193). Using ohmmeter, check resistance between terminals VC and E2 on TP sensor. (Scheme 198)and (Scheme 199). Ensure resistance is within specification. See «TP SENSOR RESISTANCE»(ref-63408-S21484680622001040600000) table. On Land Cruiser, Sequoia and Tundra, if resistance is not within specification, replace TP sensor. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. On 4Runner, if resistance is not within specification, replace throttle body with TP sensor as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. TP SENSOR RESISTANCE Application Ohms @ 68°F (20°C) Land Cruiser, Sequoia & Tundra 1250-2350 4Runner 1200-3200
15. To test accelerator pedal position sensor, disconnect electrical connector at accelerator pedal position sensor. (Scheme 192)and (Scheme 193). Using ohmmeter, check resistance between terminals VC and E2 on accelerator pedal position sensor. (Scheme 200)and (Scheme 201). Ensure resistance is within specification. See «ACCELERATOR PEDAL POSITION SENSOR RESISTANCE»(ref-63408-S16235942972001040600000) table. On Land Cruiser, Sequoia and Tundra, if resistance is not within specification, replace accelerator pedal position sensor. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. On 4Runner, if resistance is not within specification, replace throttle body with accelerator pedal position sensor as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. ACCELERATOR PEDAL POSITION SENSOR RESISTANCE Application Ohms @ 68°F (20°C) Land Cruiser, Sequoia & Tundra 1640-3280 4Runner 1200-3200

IGNITION SYSTEMS

Note. For basic ignition checks, see IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

Knock Sensors

See KNOCK SENSOR under ENGINE SENSORS & SWITCHES.

EMISSION SYSTEMS & SUB-SYSTEMS

Note. For emission system component location, refer to illustrations. (Scheme 202)- (Scheme 211).

Scheme 197

Scheme 198

Scheme 199

Scheme 200

Scheme 201

Scheme 202

Scheme 203

Scheme 204

Scheme 205

Scheme 206

System Check (Camry & Camry Solara)

Manufacturer does not list an EGR system check, only individual component testing is listed. If a problem exists in EGR system, a Diagnostic Trouble Code (DTC) P0401, P0402, P1410 or P1411 may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

EGR Gas Temperature Sensor (Camry & Camry Solara)

See EGR GAS TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES.

EGR Position Sensor (Camry & Camry Solara)

Note. EGR position sensor may also be referred to as EGR valve position sensor.

1. Disconnect electrical connector at EGR position sensor. EGR position sensor is located on top of EGR valve. see scheme 149
2. Using ohmmeter, check resistance between terminals E2 and VC on EGR position sensor. see scheme 149 Resistance should be 1500-4300 ohms. If resistance is within specification, reinstall electrical connector on EGR position sensor and go to next step. If resistance is not within specification, replace EGR position sensor.
3. To test EGR position sensor output voltage, disconnect vacuum hose from EGR valve. Remove glove box for access to Engine Control Module (ECM). Turn ignition on. Using voltmeter, check voltage between ECM terminals E2 (Brown wire) and VC (Yellow wire). see scheme 150 Voltage should be 4.5-5.5 volts. Remove voltmeter.
4. Connect voltmeter between ECM terminals E2 (Brown wire) and EGLS (White/Green wire). see scheme 151 Using vacuum pump, apply 5.1 in. Hg of vacuum to EGR valve and note voltage. Voltage should be 3.2-5.1 volts with vacuum applied on EGR valve. Release vacuum from EGR valve and note voltage. Voltage should be.4-1.6 volts with vacuum released from EGR valve. Replace EGR position sensor if voltage is not within specification. Remove vacuum pump and reinstall vacuum hose on EGR valve.

Scheme 207

Scheme 208

Scheme 209

EGR Vacuum Control Valve (Camry & Camry Solara)

Note. EGR vacuum control valve may also be referred to as EGR VCV.

1. Disconnect vacuum hoses and remove EGR vacuum control valve. EGR vacuum control valve is located on top of engine, near EGR valve. (Scheme 203)
2. Plug port "Z" and connect vacuum pump to port "S" on EGR vacuum control valve. see scheme 152
3. Using vacuum pump, apply 11.8 in. Hg of vacuum to EGR vacuum control valve. Vacuum pump should be operated 3 times so applied vacuum on EGR vacuum control valve remains at 8.6-11.8 in. Hg of vacuum.
4. Stop operating the vacuum pump after 3 times and note vacuum reading. Vacuum reading should decrease to 4.4-7.1 in. Hg of vacuum after 10 seconds. Replace EGR vacuum control valve if vacuum reading is not within specification.

Scheme 210

Scheme 211

1. Remove "V" bank cover and emission control valve set located on top of engine for access to EGR Vacuum Switching Valve (VSV). (Scheme 86)
2. Remove EGR VSV. Using ohmmeter, ensure continuity exists between electrical terminals on EGR VSV and resistance is 27-33 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists or resistance is not within specification.
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of EGR VSV. Replace EGR VSV if continuity exists between electrical terminal and body of EGR VSV.
4. To test EGR VSV operation, apply air pressure to port "E". Ensure air flows from port "G". Perform STEP 1 in illustration. see scheme 153
5. Apply battery voltage and ground to electrical terminals on EGR VSV. Apply air pressure to port "E". Ensure air flows from port "F" and not from port "G". Perform STEP 2 in illustration. see scheme 153 Replace EGR VSV if defective. Reinstall EGR VSV.

EGR Valve (Camry & Camry Solara)

1. Remove EGR valve. See EGR VALVE under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
2. Inspect EGR valve for restricted passages caused by carbon deposits. Using vacuum pump, apply vacuum directly to EGR valve and ensure valve opens. Release vacuum and ensure valve closes. Replace EGR valve if defective.

FUEL EVAPORATIVE SYSTEM

Note. Fuel evaporative system is referred to as fuel EVAP system and may contain different components depending on application. (Scheme 202)- (Scheme 211). When testing fuel EVAP system components, it may be necessary to use proper illustration to determine component location.

Note. On Avalon, Camry, Camry Solara, Highlander, Sequoia, Sienna and 4Runner, an On-Board Refilling Vapor Recovery (ORVR) system is used to recover fuel vapors into charcoal canister that are generated during refueling. ORVR system consists of fuel inlet pipe, overfill check valve, cut-off valve and charcoal canister. Overfill check valve may also be referred to as On-Board Refueling Vapor Recovery Overfill Check Valve (ORVR-OCKV) or fill check valve. Cut-off valve may also be referred to On-Board Refueling Vapor Recovery Cut-Off Valve (ORVR-COV). For testing of fuel EVAP system and ORVR system, see appropriate FUEL EVAP SYSTEM TEST.

Note. Charcoal canister may also be referred to as EVAP canister.

Charcoal Canister

For testing of charcoal canister, see appropriate FUEL EVAP SYSTEM TEST.

Cut-Off Valve (Avalon, Camry, Camry Solara, Highlander, Sequoia, Sienna & 4Runner)

Individual component testing is not available from manufacturer. Manufacturer provides testing information for testing airtightness of fuel tank and components along with testing of charcoal canister, cut-off valve and fuel EVAP system. See appropriate FUEL EVAP SYSTEM TEST.

EVAP Vacuum Switching Valve (Avalon, Camry, Camry Solara, Highlander, Land Cruiser, Sequoia, Sienna, Tacoma, Tundra & 4Runner)

1. Remove EVAP Vacuum Switching Valve (VSV). (Scheme 202)- (Scheme 211). See «EVAP VSV LOCATIONS»(ref-63408-S38277762662001020500000) table. EVAP VSV LOCATIONS Application Location Avalon Front VSV On Emission Control Valve Set On Top Of Engine, Near Intake Manifold & Contains Blue 2-Pin Electrical Connector With Black/Red & Black/White Wires Camry & Camry Solara Front VSV On Emission Control Valve Set On Top Of Engine, Near Intake Manifold & Contains Blue 2-Pin Electrical Connector With Light Green & Black/Yellow Wires Highlander Front VSV On Emission Control Valve Set On Top Of Engine, Near Intake Manifold & Contains Blue 2-Pin Electrical Connector With Black/Red & Black/White Wires Land Cruiser At Driver's Side Center Of Intake Manifold Below Intake Manifold Cover & Contains Black 2-Pin Electrical Connector With Blue/Black & Black/Yellow Wires Sequoia At Driver's Side Center Of Intake Manifold & Contains Black 2-Pin Electrical Connector With Green/Red & White/Green Wires Sienna Front VSV On Emission Control Valve Set On Top Of Engine, Near Intake Manifold & Contains Blue 2-Pin Electrical Connector With Light Green & Black/Yellow Wires Tacoma On End Of Charcoal Canister & Contains Black 2-Pin Electrical Connector With White/Red & White/Green Wires Tundra 3.4L V6 At Driver's Side Rear Corner Of Air Intake Chamber & Contains Black 2-Pin Electrical Connector With White/Blue & White/Green Wires 4.7L V8 At Driver's Side Center Of Intake Manifold & Contains Black 2-Pin Electrical Connector With Red & White/Green Wires 4Runner On Bracket Bolted To Inside Of Driver's Side Front Fender Panel & Contains Black 2-Pin Electrical Connector With White/Blue & White/Green Wires
2. Using ohmmeter, ensure continuity exists between electrical terminals on EVAP VSV and that resistance is within specification. See «EVAP VSV RESISTANCE»(ref-63408-S11986364512001020500000) table. Replace EVAP VSV if no continuity exists or resistance is not within specification. EVAP VSV RESISTANCE Application Ohms @ 68°F (20°C) Avalon, Camry, Camry Solara, Highlander & Sienna 27-33 Land Cruiser, Sequoia & Tacoma 30-34 Tundra 3.4L V6 29-33 4.7L V8 30-34 4Runner 30-34
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of EVAP VSV. Replace EVAP VSV if continuity exists between electrical terminal and body of EVAP VSV.
4. To test EVAP VSV operation, apply air pressure to port "E". Ensure air does not flow from port "F". Perform STEP 1 in illustration. (Scheme 217)- (Scheme 219).
5. Apply battery voltage and ground to electrical terminals on EVAP VSV. Apply air pressure to port "E". Ensure air flows from port "F". Perform STEP 2 in illustration. (Scheme 217)- (Scheme 219). Replace EVAP VSV if defective.

Scheme 212

Scheme 213

Scheme 214

Overfill Check Valve (Avalon, Camry, Camry Solara, Highlander, Sequoia, Sienna & 4Runner)

Individual component testing is not available from manufacturer. Manufacturer provides testing information for testing airtightness of fuel tank and components along with testing of charcoal canister, overfill check valve and fuel EVAP system. See appropriate FUEL EVAP SYSTEM TEST.

Pressure Switching Valve Vacuum Switching Valve (Avalon, Camry, Camry Solara, Highlander, Sequoia, Sienna & 4Runner)

1. Remove pressure switching valve Vacuum Switching Valve (VSV). See «PRESSURE SWITCHING VALVE VSV LOCATION»(ref-63408-S31842531462001020500000) table. (Scheme 202)- (Scheme 211). PRESSURE SWITCHING VALVE VSV LOCATION Application Location Avalon On Bracket At Charcoal Canister Near Fuel Tank & Contains 2-Pin Electrical Connector With Pink/Black & Black/White Wires Camry On Bracket At Charcoal Canister Near Fuel Tank & Contains 2-Pin Electrical Connector With Violet & Black/Yellow Wires Camry Solara On Bracket At Charcoal Canister Near Fuel Tank & Contains 2-Pin Electrical Connector With White/Red & Red Wires Highlander On Bracket At Charcoal Canister Behind Fuel Tank & Contains 2-Pin Electrical Connector With Blue/Red & White Wires Sequoia On Bracket At Charcoal Canister Near Fuel Tank & Contains 2-Pin Electrical Connector With Pink/Blue & Green/Red Wires Sienna On Bracket At Charcoal Canister Near Fuel Tank & Contains 2-Pin Electrical Connector With Black/Red & White/Red Wires 4Runner On Bracket At Charcoal Canister Near Fuel Tank & Contains 2-Pin Electrical Connector With Red/Yellow & White/Blue Wires
2. Using ohmmeter, ensure continuity exists between electrical terminals on pressure switching valve VSV and that resistance is within specification. See «PRESSURE SWITCHING VALVE VSV RESISTANCE»(ref-63408-S30396572652001021600000) table. Replace pressure switching valve VSV if no continuity exists or resistance is not within specification. PRESSURE SWITCHING VALVE VSV RESISTANCE Application Ohms @ 68°F (20°C) Avalon, Camry & Camry Solara (1) Highlander 30-36 Sequoia 37-44 Sienna & 4Runner (1) (1) Resistance should be 37-44 ohms at 68°F (20°C) and 51-62 ohms at 248 °F (120°C).
3. Ensure no continuity exists between each electrical terminal and body of pressure switching valve VSV. Replace pressure switching valve VSV if continuity exists between electrical terminal and body of pressure switching valve VSV.
4. To test pressure switching valve VSV operation, apply air pressure to port "E". Ensure air does not flow from port "F". Perform STEP 1 in illustration. (Scheme 220)
5. Apply battery voltage and ground to electrical terminals on pressure switching valve VSV. Apply air pressure to port "E". Ensure air flows from port "F". Perform STEP 2 in illustration. (Scheme 220) Replace pressure switching valve VSV if defective.

Scheme 215

Scheme 216

Scheme 217

Scheme 218

Scheme 219

Scheme 220

Scheme 221

Scheme 222

Scheme 223

Scheme 224

Scheme 225

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, disconnect electrical connector at vapor pressure sensor. (Scheme 202)- (Scheme 210). See «VAPOR PRESSURE SENSOR LOCATION»(ref-63408-S33806003632001020500000) table. VAPOR PRESSURE SENSOR LOCATION Application Location Avalon On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With White, Pink & Blue/Red Wires Camry On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With Brown, Pink & Yellow Wires Camry Solara On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With Brown, Blue/Red & Yellow Wires Land Cruiser On Rear Corner Of Charcoal Canister & Contains Black 3-Pin Electrical Connector With Brown/White, Blue/Red & Blue/Black Wires Tacoma On Firewall, Above Brake Booster & Contains Black 3-Pin Electrical Connector With Light Green, Green/Black & Red/Yellow Wires Tundra On Rear Corner Of Charcoal Canister & Contains Black 3-Pin Electrical Connector With Green/White, Red/Green & Green/Black Wires
2. Turn ignition on. Using voltmeter, measure vapor pressure sensor supply voltage between terminals VC and E2 on wiring harness side of electrical connector for vapor pressure sensor. (Scheme 221) The VC and E2 terminals are the 2 outer terminals. DO NOT use center terminal. Vapor pressure sensor supply voltage should be 4.5-5.5 volts.
3. If vapor pressure sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor. Go to next step. If vapor pressure sensor supply voltage is not within specification, check wiring circuit between Engine Control Module (ECM) and vapor pressure sensor. See «ECM LOCATION»(ref-63408-S16698749512001020500000) table. See WIRING DIAGRAMS article.
4. To test vapor pressure sensor output voltage, turn ignition on. Disconnect vacuum hose from vapor pressure sensor. (Scheme 222)- (Scheme 225).
5. Obtain access to Engine Control Module (ECM). See «ECM LOCATION»(ref-63408-S16698749512001020500000) table. Connect voltmeter between specified ECM terminals. (Scheme 226)- (Scheme 230). See «ECM TERMINAL APPLICATION»(ref-63408-S28873127492001020500000) table. ECM LOCATION Model (1) Location Avalon Behind Glove Box, Near Passenger's Side Kick Panel Camry & Camry Solara Behind Glove Box Land Cruiser Above Glove Box, Near Passenger's Side Of Instrument Panel Tacoma Behind Glove Box Tundra Behind Glove Box & Heater Duct (1) For illustration of ECM location, see THEORY & OPERATION article. ECM TERMINAL APPLICATION Application & Terminal Wire Color Avalon E2 White PTNK Pink Camry E2 Brown PTNK Pink Camry Solara E2 Brown PTNK Blue/Red Land Cruiser E2 Brown/White PTNK Blue/Black Tacoma E2 Light Green PTNK Red/Yellow Tundra E2 Green/White PTNK Red/Green
6. Using vacuum pump, apply.59 in. Hg of vacuum to vapor pressure sensor and note vapor pressure sensor output voltage. Ensure vapor pressure sensor output voltage is within specification. See «VAPOR PRESSURE SENSOR OUTPUT VOLTAGE»(ref-63408-S08349896942001020500000) table.
7. Release vacuum from vapor pressure sensor and note vapor pressure sensor output voltage. Ensure vapor pressure sensor output voltage is within specification. See «VAPOR PRESSURE SENSOR OUTPUT VOLTAGE»(ref-63408-S08349896942001020500000) table.
8. Apply.22 psi (.015 kg/cm 2 ) to vapor pressure sensor and note vapor pressure sensor output voltage. Ensure vapor pressure sensor output voltage is within specification. See «VAPOR PRESSURE SENSOR OUTPUT VOLTAGE»(ref-63408-S08349896942001020500000) table. Replace vapor pressure sensor if vapor pressure sensor output voltage is not within specification. Reconnect vacuum hose. VAPOR PRESSURE SENSOR OUTPUT VOLTAGE Condition Volts Vacuum Applied 1.3-2.1 Vacuum Released 3.0-3.6 Pressure Applied 4.2-4.8

Vapor Pressure Sensor (Highlander)

Testing information is not available from manufacturer.

Scheme 226

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, obtain access to electrical connector at vapor pressure sensor. Vapor pressure sensor is located on top of fuel pump assembly on top of fuel tank and uses a Black 3-pin electrical connector. (Scheme 206), (Scheme 207) and (Scheme 211). On Sequoia and Sienna, it may be necessary to lower fuel tank for access to vapor pressure sensor. On 4Runner, vapor pressure sensor may be accessed by removing remove driver's side rear seat cushion and cover plate on floor panel.
2. On all models, disconnect electrical connector from vapor pressure sensor. Turn ignition on. Using voltmeter, measure vapor pressure sensor supply voltage between terminals No. 1 and 3 on wiring harness side of electrical connector for vapor pressure sensor. (Scheme 231) DO NOT use center terminal. Vapor pressure sensor supply voltage should be 4.5-5.5 volts.
3. If vapor pressure sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor. Go to next step. If vapor pressure sensor supply voltage is not within specification, check wiring circuit between Engine Control Module (ECM) and vapor pressure sensor. See WIRING DIAGRAMS article. On Sequoia, ECM is located behind glove box and heater duct. On Sienna, ECM is located at passenger's side of instrument panel, just below glove box. On 4Runner, ECM is located behind glove box. On all models, for illustration of ECM location, see THEORY & OPERATION article.
4. To test vapor pressure sensor output voltage, turn ignition on. Remove fuel tank cap. Using voltmeter, measure vapor pressure sensor output voltage between terminals No. 2 and 3 on wiring harness side of electrical connector for vapor pressure sensor with electrical connector installed on vapor pressure sensor. (Scheme 231)
5. Vapor pressure sensor output voltage should be 3.0-3.6 volts. Replace vapor sensor if vapor pressure sensor output voltage is not within specification. Turn ignition off. Reinstall fuel tank cap.

Vapor Pressure Sensor Vacuum Switching Valve (Land Cruiser, Tacoma & Tundra)

1. Remove vapor pressure sensor Vacuum Switching Valve (VSV). Vapor pressure sensor VSV is located on charcoal canister. (Scheme 205)and (Scheme 208) - (Scheme 210).
2. Using ohmmeter, ensure continuity exists between electrical terminals on vapor pressure sensor VSV and that resistance is 37-44 ohms at 68°F (20°C). Replace vapor pressure sensor VSV if no continuity exists or resistance is not within specification.
3. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of vapor pressure sensor VSV. Replace vapor pressure sensor VSV if continuity exists between electrical terminal and body of vapor pressure sensor VSV.
4. To test vapor pressure sensor VSV operation, apply air pressure to port "E". Ensure air flows from port "G" and not from port "F". Perform STEP 1 in illustration. (Scheme 232)and (Scheme 233).
5. Apply battery voltage and ground to electrical terminals on vapor pressure sensor VSV. Apply air pressure to port "E". Ensure air flows from port "F" and not from port "G". Perform STEP 2 in illustration. (Scheme 232)and (Scheme 233). Replace vapor pressure sensor VSV if defective.

Scheme 227

Scheme 228

Avalon, Camry, Camry Solara, Highlander, Land Cruiser, Sequoia, Sienna, Tacoma & Tundra 4.7L V8

1. Remove Positive Crankcase Ventilation (PCV) valve. See «PCV VALVE LOCATION»(ref-63408-S26995051662001020500000) table.
2. Apply air pressure to PCV valve at bottom (cylinder head side) of PCV valve. Ensure air flows easily through PCV valve. Apply air pressure to PCV valve at vacuum side (intake manifold side) of PCV valve. Ensure air flows through PCV valve with some resistance. Replace PCV valve if valve does not function as described.

Tundra 3.4L V6 & 4Runner

1. Positive Crankcase Ventilation (PCV) valve. See «PCV VALVE LOCATION»(ref-63408-S26995051662001020500000) table.
2. Apply air pressure to PCV valve at bottom (cylinder head side) of PCV valve. Ensure air flows easily through PCV valve. Apply air pressure to PCV valve at vacuum side (intake manifold side) of PCV valve. Ensure air flows through PCV valve with some resistance.
3. Apply air pressure to PCV valve at vacuum side (intake manifold side) of PCV valve while using small screwdriver to push upward on valve located inside PCV valve at bottom (cylinder head side) of PCV valve. Ensure air flows through PCV valve with strong resistance. Replace PCV valve if valve does not function as described. PCV VALVE LOCATION Application Location Avalon, Camry, Camry Solara, Highlander & Sienna On Firewall Side Valve Cover At Timing Belt End Of Engine Land Cruiser & Sequoia At Front Of Driver's Side Valve Cover, Below Oil Fill Cap Tacoma & 4Runner Front Of Passenger's Side Valve Cover Tundra 3.4L V6 Front Of Passenger's Side Valve Cover 4.7L V8 At Front Of Driver's Side Valve Cover, Below Oil Fill Cap

Tacoma With M/T

1. Start engine. Warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 article. Shut engine off. Remove cap, filter and separator from dashpot on throttle body. (Scheme 234)
2. Start engine. Maintain engine speed at 2500 RPM. Plug Vacuum Transmitting Valve (VTV) hole in dashpot with your finger. (Scheme 235)
3. Release throttle. Dashpot should be extended and dashpot setting RPM should be 1800-2200 RPM. If dashpot setting RPM is not within specification, rotate dashpot adjusting screw to obtain correct RPM. (Scheme 236)
4. Remove finger from VTV hole in dashpot. Ensure engine returns to proper idle speed in approximately one second. Install separator, filter and cap. Ensure filter is installed with the coarse surface facing outward (away from dashpot).

Scheme 229

Scheme 230

Scheme 231

Note. Electronic Throttle Control System (ETCS) may also be referred to as Electronic Throttle Control System-Intelligent (ETCS-I or ETCS-i).

For testing of throttle body and components, see THROTTLE BODY under IDLE CONTROL SYSTEMS.

1. Start engine. Warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - V6 & V8 article.
2. Shut engine off. Disconnect and plug vacuum hose at throttle opener near throttle body. (Scheme 237)- (Scheme 239). Start engine and note engine speed. Engine speed should be within specification. See «THROTTLE OPENER SPECIFICATIONS»(ref-63408-S40793670432001020500000) table.
3. If engine speed is not within specification, replace throttle body. Shut engine off. Reinstall vacuum hose on throttle opener. Start engine and ensure engine returns to proper idle speed. THROTTLE OPENER SPECIFICATIONS (1) Application RPM Avalon 1100-1700 Camry, Camry Solara, Sienna, Tacoma & Tundra 900-1950 (1) Check with throttle opener vacuum hose disconnected and plugged, engine at normal operating temperature and electric cooling fan turned off (if equipped).

Scheme 232

Scheme 233

Scheme 234

VARIABLE VALVE TIMING SYSTEM

Note. Variable Valve Timing (VVT) system is used on Avalon, Highlander and Sienna. If problem exists in VVT system, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

Variable Valve Timing (VVT) sensor may also be referred to as camshaft position sensor. For testing camshaft position sensor, see CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article.

VARIABLE VALVE TIMING CAMSHAFT TIMING OIL CONTROL VALVE

Note. Variable Valve Timing (VVT) camshaft timing oil control valve may also be referred to as oil control valve for VVT, VVT Oil Control Valve (OCV) or camshaft timing oil control valve VVT.

Scheme 235

Scheme 236

1. Remove "V" bank cover on top of engine for access to VVT camshaft timing oil control valves. VVT camshaft timing oil control valves are located on end of cylinder head at flywheel end of engine. see scheme 197
2. To check VVT camshaft timing oil control valve resistance, disconnect electrical connector at appropriate VVT camshaft timing oil control valve. Using ohmmeter, check resistance between electrical terminals on VVT camshaft timing oil control valve. Resistance should be 6.9-7.9 ohms at 68°F (20°C). If resistance is within specification, go to next step. If resistance is not within specification, replace VVT camshaft timing oil control valve.
3. To check VVT camshaft timing oil control valve operation, remove retaining bolt and appropriate VVT camshaft timing oil control valve with "O" ring from cylinder head. Note movement of the valve inside VVT camshaft timing oil control valve while applying and disconnecting battery voltage and ground to terminals No. 1 and 2 on VVT camshaft timing oil control valve. (Scheme 240) Valve should move outward toward end of assembly opposite electrical connector with voltage applied and should move inward toward electrical connector end of assembly with voltage not applied. (Scheme 240) Replace VVT camshaft timing oil control valve if operation is not as specified. Reinstall VVT camshaft timing oil control valve using NEW "O" ring. Tighten retaining bolt to 66 INCH lbs. (7.5 N.m).

Scheme 237

Scheme 238

Scheme 239

1. Manufacturer does not provide complete system testing, only individual components. To test the active control engine mount, note location active control engine mount at the front (radiator side) of the engine, just below exhaust manifold. (Scheme 241) Manufacturer lists testing procedure for active control engine mount with the mount assembly removed.
2. Disconnect vacuum hose from vacuum fitting on active control engine mount and connect vacuum pump to vacuum fitting. (Scheme 242) Using vacuum pump, apply 25.0 in. Hg of vacuum to active control engine mount for at least one minute and check that no change exists is the needle movement. Needle is located at the bottom of active engine control mount. (Scheme 242) Check for signs of fluid leakage on active engine mount. If active control engine mount does not operate as specified or signs of fluid leakage exist, replace active control engine mount.
3. To test Active Control Mount Vacuum Switching Valve (ACM VSV), remove ACM VSV. ACM VSV is located near active control engine mount at the front (radiator side) of the engine, just below exhaust manifold. (Scheme 241) Using ohmmeter, check that continuity exists between electrical terminals on ACM VSV and that resistance is 19-21 ohms at 68°F (20°C). If continuity exists and that resistance is within specification, go to next step. If no continuity exists or resistance is not within specification, replace ACM VSV.
4. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of ACM VSV. If continuity does not exist between electrical terminal and body of ACM VSV, go to next step. If continuity exists between electrical terminal and body of ACM VSV, replace ACM VSV.
5. To check ACM VSV operation, apply air pressure to port "G" on ACM VSV. Ensure air flows from ports "E" and "H". Perform STEP 1 in illustration. (Scheme 243) Apply battery voltage and ground to electrical terminals on ACM VSV. Apply air pressure to port "F" on ACM VSV. Ensure air flows from ports "E" and "H". Perform STEP 2 in illustration. (Scheme 243) If ACM VSV operates properly, reinstall ACM VSV. If ACM VSV does not operate properly, replace ACM VSV.
6. To test vacuum tank, disconnect hoses from vacuum tank. Vacuum tank is located near driver's side front corner of engine compartment, below battery tray. Apply air pressure to port "B" on vacuum tank. Ensure air flows from port "A". Perform STEP 1 in illustration. see scheme 202 Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2 in illustration. see scheme 202
7. Plug port "B". Using vacuum pump, apply 7.9 in. Hg of vacuum to port "A". Perform STEP 3 in illustration. see scheme 202 Ensure vacuum reading will hold for at least one minute. If vacuum tank is okay, reconnect vacuum hoses. If vacuum tank is defective, replace vacuum tank.

Scheme 240

Scheme 241

Scheme 242

Scheme 243

1. Check vacuum hoses for active control engine mount system for looseness, damage, restrictions or being disconnected. see scheme 203 Ensure cap is installed on end of vacuum hose "C". see scheme 203 If cap is missing from vacuum hose "C" or vacuum hose "C" is damaged, replace vacuum hose "C" as an assembly. DO NOT repair this vacuum hose by cutting and splicing in another vacuum hose. If all vacuum hoses and connections are okay, go to next step. If vacuum hoses and connections are defective, repair or replace components as necessary.
2. Start engine. Warm engine to normal operating temperature. Connect Toyota hand-held tester to data link connector No. 3. (Scheme 97) Turn hand-held tester on. Select ACM INHIBIT ACTIVE TEST on hand-held tester. Place transaxle in Park or Neutral. Check whether or not engine vibration increases while ACM INHIBIT ACTIVE TEST is in the ON state. If engine vibration increases while ACM INHIBIT ACTIVE TEST is in the ON state, shut engine off. Remove hand-held tester. Go to next step. If engine vibration does not increase while ACM INHIBIT ACTIVE TEST is in the ON state, shut engine off. Remove hand-held tester. Go to step 4.
3. Start engine. Warm engine to normal operating temperature. Chock all 4 wheels and apply parking brake. Depress brake and place transaxle in Drive. Disconnect vacuum hose "A" at upper cap on air cleaner assembly. see scheme 203 Place your finger over end of disconnected vacuum hose "A" and check that suction exists intermittently. If suction does not exist intermittently, shut engine off. Reinstall vacuum hose "A" on upper cap on air cleaner assembly. Go to next step. If suction exists intermittently, shut engine off. Reinstall vacuum hose "A" on upper cap on air cleaner assembly. Active control engine mount system is operating properly.
4. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Connect oscilloscope leads between terminal ACM1 (Black wire) on ECM electrical connector E7 and terminal E1 (Brown wire) on ECM electrical connector E8. see scheme 204
5. Start engine. Warm engine to normal operating temperature. Apply parking brake. Note voltage reading on oscilloscope with transaxle in proper gear position and in accordance with engine speed. See «VOLTAGE SPECIFICATIONS»(ref-63408-S29379767752001033000000) table. If voltage is not as specified, shut engine off. Remove oscilloscope. Go to next step. If voltage is as specified, shut engine off. Remove oscilloscope. Go step 11. VOLTAGE SPECIFICATIONS Condition Voltage Transaxle In Park 9-14 Transaxle In Drive With Engine Speed 900 RPM Or More 9-14 Transaxle In Drive With Engine Speed Less Than 900 RPM (1) (1) Voltage should pulse at intervals. see scheme 204
6. Disconnect electrical connector at Active Control Mount Vacuum Switching Valve (ACM VSV). ACM VSV is located near active control engine mount at the front (radiator side) of the engine, just below exhaust manifold. see scheme 203 Using ohmmeter, check resistance between electrical terminals on ACM VSV. Resistance should be 19-21 ohms at 68°F (20°C). If resistance is within specification, go to next step. If resistance is not within specification, replace ACM VSV.
7. Ensure electrical connector at ACM VSV is still disconnected. Remove EFI main relay from fuse/relay box at driver's side front corner of engine compartment, near battery. see scheme 205 EFI main relay may also be referred to as EFI relay. To check for open in wiring between EFI main relay and ACM VSV, using ohmmeter, check resistance between cavity No. 3 (Black/White wire) in fuse/relay box for EFI main relay and terminal No. 1 (Black/White wire) on electrical connector for ACM VSV. see scheme 205 If resistance is one ohm or less, go to next step. If resistance is more than one ohm, repair open on Black/White wire between EFI main relay and ACM VSV. See WIRING DIAGRAMS article.
8. To check for short in wiring between EFI main relay output circuit and ground, using ohmmeter, check for continuity between cavities No. 2 (White/Black wire) and No. 3 (Black/White wire) in fuse/relay box for EFI main relay. see scheme 205 If no continuity exists, go to next step. If continuity exists, repair short in EFI main relay output circuit and ground between cavities No. 2 (White/Black wire) and No. 3 (Black/White wire) in fuse/relay box for EFI main relay. See WIRING DIAGRAMS article.
9. Ensure ignition is off. Disconnect ECM electrical connector E7. see scheme 204 To check for open in wiring between ECM and ACM VSV, using ohmmeter, check resistance between terminal ACM1 (Black wire) on ECM electrical connector E7 and terminal No. 2 (Black wire) on ACM VSV electrical connector. see scheme 204and see scheme 205. If resistance is one ohm or less, go to next step. If resistance is more than one ohm, repair open on Black wire between ECM and ACM VSV. See WIRING DIAGRAMS article.
10. To check for short in wiring between ECM and ACM VSV, using ohmmeter, check for continuity between terminal ACM1 (Black wire) on ECM electrical connector E7 and terminal E1 (Brown wire) on ECM electrical connector E8. see scheme 204 If continuity exists, repair short to ground in Black wire between ECM and ACM VSV. See WIRING DIAGRAMS article. If no continuity exists, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is okay, replace ECM. If ECM is replaced and vehicle is equipped with engine immobilizer system, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
11. Remove Active Control Mount Vacuum Switching Valve (ACM VSV). ACM VSV is located near active control engine mount at the front (radiator side) of the engine, just below exhaust manifold. see scheme 203 Apply air pressure to port "G" on ACM VSV. Ensure air flows from ports "E" and "H". Perform STEP 1 in illustration. (Scheme 243) Apply battery voltage and ground to electrical terminals on ACM VSV. Apply air pressure to port "F" on ACM VSV. Ensure air flows from ports "E" and "H". Perform STEP 2 in illustration. (Scheme 243) If ACM VSV operates properly, reinstall ACM VSV. Go to next step. If ACM VSV does not operate properly, replace ACM VSV.
12. Disconnect vacuum hose from vacuum fitting on active control engine mount and connect vacuum pump to vacuum fitting. see scheme 206 Using vacuum pump, apply 25.0 in. Hg of vacuum to active control engine mount for at least one minute and check that no change exists is the needle movement. Needle is located at the bottom of active engine control mount. see scheme 206 Check for signs of fluid leakage on active engine mount. If active control engine mount operates properly, active control engine mount system is operating properly. If active control engine mount does not operate as specified or signs of fluid leakage exist, replace active control engine mount.