Engine Controls - System & Component Testing - 4-CYLINDER: Other Toyota Prius I рестайлинг

PRIUS

The following service precautions must be followed

Scheme 87

1. Ensure ignition is off and ignition key is removed from ignition before performing any inspection or service procedure in engine compartment, as engine may automatically start and shut off when ignition is on and READY light is illuminated. READY light is displayed just above the shift lever position indicator on instrument cluster at center of instrument panel.
2. Read all service and warning labels in engine compartment before performing any procedures in engine compartment.
3. All high-voltage wiring harness connectors contain Orange connectors. DO NOT touch any wiring harness that contains Orange connectors.
4. High-voltage battery and other high-voltage components may be identified by HIGH VOLTAGE caution labels on them. DO NOT touch these components.
5. If necessary to inspect or service high-voltage system, ensure ignition is off. Remove service plug and wait at least 5 minutes to ensure high voltage is fully discharged before touching any high-voltage wiring harness, connectors or components. Service plug is located on service plug assembly at driver's side front corner of trunk compartment, near high-voltage battery. (Scheme 87) Ensure service plug is stored in a location in which no one may install service plug while technician is working on the vehicle.
6. If necessary to touch any high-voltage wiring harness, connectors or components, ensure service plug is removed and battery voltage or less exists at electrical connector. Use Toyota insulated gloves when touching any high-voltage wiring harness, connectors or components. Ensure insulated gloves are dry and in good condition and that no holes exist in insulated gloves by applying air to insulated glove before touching any high-voltage wiring harness, connectors or components.
7. DO NOT wear any metal objects while working on vehicle which may accidently drop and cause a short circuit.
8. If any high-voltage wiring harness connector is disconnected, ensure terminal on wiring harness connector is wrapped with tape to prevent wiring harness connector from contacting any surface.
9. If servicing high-voltage system, place sign on roof of vehicle to indicate to other technicians that high-voltage system is being serviced.

Celica

Note. Acoustic Control Induction System (ACIS) Vacuum Switching Valve (VSV) may also be referred to as intake air control valve system VSV.

Scheme 88

Scheme 89

1. Remove necessary components for access to ACIS VSV. ACIS VSV is located on bottom of air cleaner case. (Scheme 88)
2. Remove ACIS VSV. Using ohmmeter, ensure continuity exists between electrical terminals on ACIS VSV and that resistance is 37-44 ohms at 68°F (20°C). Replace ACIS 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 ACIS VSV. Replace ACIS VSV if continuity exists between electrical terminal and body of ACIS VSV.
4. To test ACIS VSV operation, apply air pressure to port "E". Ensure air flows from port "G". Perform STEP 1 in illustration. (Scheme 89)
5. Apply battery voltage and ground to electrical terminals on ACIS VSV. Apply air pressure to port "E". Ensure air flows from port "F" and not from port "G". Perform STEP 2 in illustration. (Scheme 89) Replace ACIS VSV if defective. Reinstall ACIS VSV.

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).

2001 MR2 With Sequential Manual Transaxle & Prius

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

Camry CNG Models, Camry Gasoline Models With Manual A/C, Camry Solara With Manual A/C & MR2

Scheme 90

1. Check A/C compressor drive belt for proper adjustment. See SERVICE & ADJUSTMENT SPECIFICATIONS article for proper drive belt tension. If A/C compressor drive belt has proper belt tension, go to next step. If A/C compressor drive belt does not have proper belt tension, adjust drive belt to specification if automatic belt tensioner is not used and go to next step.
2. Start engine and note if A/C compressor locks when blower and A/C switches are in ON position. If A/C compressor does not lock, go to next step. If A/C compressor locks, repair A/C compressor as necessary.
3. Check A/C compressor lock sensor. See «A/C COMPRESSOR LOCK SENSOR»(ref-63407-S04926112812001020500000) under ENGINE SENSORS & SWITCHES. If A/C compressor lock sensor is okay, go to next step. If A/C compressor lock sensor is defective, replace A/C compressor lock sensor. On some models, it may be necessary to replace A/C compressor along with A/C compressor lock sensor.
4. On Camry and Camry Solar, remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. On MR2, remove luggage compartment lids, luggage compartment boxes and quarter trim panels for access to Engine Control Module (ECM). ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. For illustration of ECM location, see THEORY & OPERATION article. For additional information on removal of luggage compartment components, see FUEL PUMP under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
5. On all models, note ECM electrical connector terminals. (Scheme 108), (Scheme 109) and (Scheme 115). Connect oscilloscope between proper terminals on ECM for A/C compressor lock sensor. See «ECM TERMINAL IDENTIFICATION & CIRCUIT IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR»(ref-63407-S06012383792001020500000) table. These are the LCK1 and E1 terminals at ECM. ECM TERMINAL IDENTIFICATION & CIRCUIT IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR Application ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E7 (1) 26 (White/Blue) E6 (2) 17 (Brown) Gasoline Models With Engine Immobilizer E11 (1) 25 (White/Blue) E10 (2) 17 (Brown) Without Engine Immobilizer E11 (1) 26 (White/Blue) E10 (2) 17 (Brown) Camry Solara With Engine Immobilizer E11 (1) 25 (White/Blue) E10 (2) 17 (Brown) Without Engine Immobilizer E11 (1) 26 (White/Blue) E10 (2) 17 (Brown) MR2 E3 (1) 28 (White/Red) E4 (2) 17 (Brown) (1) This is the A/C compressor lock sensor signal circuit at ECM. (2) This is the ground circuit at ECM.
6. Check A/C compressor lock sensor wave pattern on oscilloscope during cranking or with engine idling. A/C compressor lock sensor wave pattern should switch from between zero volts and.2 volts within 20 milliseconds. (Scheme 90) If A/C compressor lock sensor wave pattern is as specified, go to next step. If A/C compressor lock sensor wave pattern is not at specified, replace A/C compressor lock sensor. On some models, it may be necessary to replace A/C compressor along with A/C compressor lock sensor. Consult local Toyota parts department for parts availability.
7. On Camry and Camry Solara, go to next step. On MR2, check A/C compressor clutch relay. See «A/C COMPRESSOR CLUTCH RELAY»(ref-63407-S26052628132000120800000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If A/C compressor clutch relay is okay, go to next step. If A/C compressor clutch relay is defective, replace A/C compressor clutch relay.
8. On all models, check wiring harness and electrical connectors for A/C compressor lock sensor between ECM and A/C compressor lock sensor for any problems. «ECM TERMINAL IDENTIFICATION & CIRCUIT IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR»(ref-63407-S06012383792001020500000) table. If wiring harness or electrical connector is 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 Camry gasoline models, Camry Solara and MR2, 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.

Celica & Highlander

Testing information is not available from manufacturer.

RAV4

Scheme 91

1. Remove glove box for access to Engine Control Module (ECM). ECM is located near passenger's side kick panel, just below instrument panel. For illustration of ECM location, see THEORY & OPERATION article. Note terminals on ECM electrical connector. (Scheme 117)
2. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 15 (Red/Yellow or White wire) at ECM electrical connector E7. This is the ACMG terminal on ECM. There are 2 different wiring harnesses used. Wire color at designated terminal may vary according to wiring harness used. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check Red/Yellow or White wire and electrical connector between ECM and terminal No. 3 (Red/Yellow or White wire) at electrical connector 3S on passenger's side junction block Electronic Control Unit (ECU). (Scheme 91)
3. Check A/C compressor drive belt for proper tension. If A/C compressor drive belt has proper belt tension, go to next step. If A/C compressor drive belt does not have proper belt tension, it may be necessary to replace automatic belt tensioner and then go to next step.
4. Start engine and note if A/C compressor locks when blower and A/C switches are in ON position. If A/C compressor does not lock, go to next step. If A/C compressor locks, repair A/C compressor as necessary.
5. Check A/C compressor lock sensor. See «A/C COMPRESSOR LOCK SENSOR»(ref-63407-S04926112812001020500000) under ENGINE SENSORS & SWITCHES. If A/C compressor lock sensor is okay, go to next step. If A/C compressor lock sensor is defective, replace A/C compressor lock sensor.
6. Check wiring harness and electrical connectors between A/C compressor lock sensor, passenger's side junction block ECU, A/C amplifier and ECM. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. A/C amplifier is located behind center of instrument panel. (Scheme 91) If wiring harness or electrical connector is 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.

Camry CNG & Gasoline Models, Camry Solara, Highlander, MR2 & RAV4

Testing information is not available from manufacturer.

Scheme 92

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 10.
2. Connect hand-held tester to data link connector No. 3. (Scheme 101) Turn ignition on and then turn hand-held tester on. Start engine and turn A/C switch to ON position. Ensure A/C clutch engages.
3. Select ACTIVE TEST MODE on hand-held tester. Check operation of A/C clutch when A/C-cut control is operated by hand-held tester. A/C clutch should turn off (stop operating) when A/C-cut control is operated by hand-held tester. If A/C clutch does not operate properly, go to next step. If A/C clutch operates properly, shut engine off. Remove hand-held tester. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
4. Check for open and short in wiring harness and electrical connectors between Engine Control Module (ECM) and A/C amplifier. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. ECM is located behind stereo on instrument panel, just in front of center console. For illustration of ECM location, see THEORY & OPERATION article. A/C amplifier is located behind instrument panel, just above glove box, near center of glove box area. (Scheme 92) If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
5. Remove necessary components for access to ECM. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Remove bolts from ECM so electrical connectors can be accessed on ECM. Note ECM electrical connector terminals. (Scheme 111)and (Scheme 112).
7. Start engine. On 3-speed A/T and M/T models, using voltmeter, check voltage between body ground and terminal No. 21 (Red/Blue wire) at ECM electrical connector E6 while turning A/C switch from ON to OFF positions. (Scheme 111) This is the ACT terminal at ECM. On 4-speed A/T models, using voltmeter, check voltage between body ground and terminal No. 12 (Red/Blue wire) at ECM electrical connector E10 while turning A/C switch from ON to OFF positions. (Scheme 112) This is the ACT terminal at ECM.
8. On all models, voltage should be 9-14 volts with A/C switch in ON position and less than 1.5 volts with A/C switch in OFF position. If voltage is as specified, go to next step. If voltage is not as specified, check for open and short in wiring harness and electrical connectors between ECM and A/C amplifier. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. A/C amplifier is located behind instrument panel, just above glove box, near center of glove box area. (Scheme 92) If wiring harness and electrical connectors are okay, replace A/C amplifier. If wiring harness or electrical connector is defective, repair as necessary.
9. 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.
10. Remove necessary components for access to Engine Control Module (ECM). See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
11. Remove bolts from ECM so electrical connectors can be accessed on ECM. Note ECM electrical connector terminals. (Scheme 111)and (Scheme 112).
12. Start engine. On 3-speed A/T and M/T models, using voltmeter, check voltage between body ground and terminal No. 21 (Red/Blue wire) at ECM electrical connector E6 while turning A/C switch from ON to OFF positions. This is the ACT terminal at ECM. On 4-speed A/T models, using voltmeter, check voltage between body ground and terminal No. 12 (Red/Blue wire) at ECM electrical connector E10 while turning A/C switch from ON to OFF positions. This is the ACT terminal at ECM.
13. On all models, voltage should be 9-14 volts with A/C switch in ON position and less than 1.5 volts with A/C switch in OFF position. If voltage is not as specified, go to next step. If voltage is as specified, 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.
14. Check for open and short in wiring harness and electrical connectors between ECM and A/C amplifier. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. A/C amplifier is located behind instrument panel, just above glove box, near center of glove box area. (Scheme 92) If wiring harness and electrical connectors are okay, replace A/C amplifier. If wiring harness or electrical connector is defective, repair as necessary.

Scheme 93

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 7.
2. Connect hand-held tester to data link connector No. 3. (Scheme 105) Turn ignition on and then turn hand-held tester on. Start engine and turn A/C switch to ON position. Ensure A/C clutch engages.
3. Select ACTIVE TEST MODE on hand-held tester. Check operation of A/C clutch when A/C-cut control is operated by hand-held tester. A/C clutch should turn off (stop operating) when A/C-cut control is operated by hand-held tester. If A/C clutch does not operate properly, go to next step. If A/C clutch operates properly, shut engine off. Remove hand-held tester. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
4. Check for open and short in wiring harness and electrical connectors between Engine Control Module (ECM) and A/C amplifier. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. ECM is located behind glove box. (Scheme 93) A/C amplifier is attached to rear of center cluster module control. (Scheme 93) If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
5. Remove ECM with electrical connectors still attached. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
6. Note ECM electrical connector terminals. (Scheme 116) Start engine. Using voltmeter, check voltage between body ground and terminal No. 22 (Pink/Green wire) at ECM electrical connector E10 while turning A/C switch from ON to OFF positions. This is the ACT terminal at ECM. Voltage should be 9-14 volts with A/C switch in ON position and less than 1.5 volts with A/C switch in OFF position. If voltage is not as specified, replace A/C amplifier. If voltage is as specified, 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.
7. Remove ECM with electrical connectors still attached. ECM is located behind glove box. (Scheme 93) See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Note ECM electrical connector terminals. (Scheme 116) Start engine. Using voltmeter, check voltage between body ground and terminal No. 22 (Pink/Green wire) at ECM electrical connector E10 while turning A/C switch from ON to OFF positions. This is the ACT terminal at ECM. Voltage should be 9-14 volts with A/C switch in ON position and less than 1.5 volts with A/C switch in OFF position. If voltage is not as specified, go to next step. If voltage is as specified, 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.
9. Check for open and short in wiring harness and electrical connectors between ECM and A/C amplifier. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. A/C amplifier is attached to rear of center cluster module control. (Scheme 93) If wiring harness and electrical connectors are okay, replace A/C amplifier. If wiring harness or electrical connector is defective, repair as necessary.

Camry CNG Models, Camry Gasoline Models With Manual A/C & Camry Solara With Manual A/C

1. 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 108)and (Scheme 109).
2. Turn ignition on. Using voltmeter, check voltage between proper terminals on ECM for A/C evaporator temperature sensor. See «ECM TERMINAL IDENTIFICATION FOR A/C EVAPORATOR TEMPERATURE SENSOR»(ref-63407-S00073605172001020500000) table. These are the THR and E2 terminals at ECM. ECM TERMINAL IDENTIFICATION FOR A/C EVAPORATOR TEMPERATURE SENSOR Application ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E7 25 (Blue/Red) E6 18 (Brown) Gasoline Models With Engine Immobilizer E11 13 (Blue/Red) E10 18 (Brown) Without Engine Immobilizer E11 25 (Blue/Red) E10 18 (Brown) Camry Solara With Engine Immobilizer E11 13 (Blue/Red) E10 18 (Brown) Without Engine Immobilizer E11 25 (Blue/Red) E10 18 (Brown)
3. Voltage should be 2.2-2.6 volts at 32°F (0°C) and 1.4-1.8 volts at 59°F (15°C). If voltage is not within specification, go to next step. If voltage is 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 Camry gasoline models and Camry Solara, 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.
4. Check A/C evaporator temperature sensor operation. See «A/C EVAPORATOR TEMPERATURE SENSOR»(ref-63407-S36167230372001020500000) under ENGINE SENSORS & SWITCHES. If A/C evaporator temperature sensor operates properly, go to next step. If A/C evaporator temperature sensor is defective, replace A/C evaporator temperature sensor. See A/C EVAPORATOR TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
5. Check wiring harness and electrical connectors between ECM and A/C evaporator temperature sensor. See WIRING DIAGRAMS article. It may be necessary to see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING for complete wiring diagram. If wiring harness or electrical connector is 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 Camry gasoline models and Camry Solara, 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.

Camry CNG Models

1. 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 108)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Yellow wire) at ECM electrical connector E4 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 is defective, repair as necessary.
3. Turn ignition off. Check for open and short in Black/Yellow wire between EFI main relay and terminal No. 16 (Black/Yellow wire) at ECM electrical connector E4. See WIRING DIAGRAMS article. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If wiring is okay, go to next step. If wiring is defective, repair as necessary.
4. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 19 (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 8.
5. 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.
6. 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.
7. Check for open and short in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 19 (Black/Red wire) at ECM electrical connector E5. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
8. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 21 (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.
9. 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.
10. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
11. Check for open and short in wiring harness and electrical connectors between terminal No. 21 (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 is defective, repair as necessary.
12. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or and electrical connectors as necessary.

Camry Gasoline Models Without Engine Immobilizer & Camry Solara Without Engine Immobilizer

1. 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 109)
2. Turn ignition on. On Camry, 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. On Camry Solara, 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. On all models, 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 is defective, repair as necessary.
3. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
4. 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.
5. Check for open and short in wiring harness and electrical connectors between EFI main relay and +B terminal at ECM. 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.
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 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.
8. Check for open in wiring harness and electrical connectors between ignition switch and EFI main relay, and between body ground and EFI main relay. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, test is complete. If wiring harness or electrical connector is defective, repair as necessary.

Camry Gasoline Models With Engine Immobilizer & Camry Solara With Engine Immobilizer

1. 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 109)
2. Turn ignition on. On Camry gasoline models, 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. On Camry Solara, 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. On all models, 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 is defective, repair as necessary.
3. Turn ignition off. On Camry gasoline models, check for open and short in Black/Yellow wire between EFI main relay and terminal No. 16 at ECM electrical connector E7. See WIRING DIAGRAMS. On Camry Solara, check for open and short in Red wire between EFI main relay and terminal No. 16 at ECM electrical connector E7. See WIRING DIAGRAMS article. On all models, EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If wiring is okay, go to next step. If wiring is defective, repair as necessary.
4. Turn ignition 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 8.
5. 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.
6. 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.
7. 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. Repair wiring harness or electrical connectors as necessary.
8. Ensure ignition is on. On Camry gasoline models, using voltmeter, check voltage between body ground and terminal No. 8 (Black/White wire) at ECM electrical connector E7. On Camry Solara models, using voltmeter, check voltage between body ground and terminal No. 8 (Black/Red wire) at ECM electrical connector E7. On all models, 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.
9. 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.
10. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
11. On Camry gasoline models, 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. On Camry Solara, 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. On all models, if wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
12. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair wiring harness or and electrical connectors as necessary.

1. Remove cover for access to Engine Control Module (ECM). ECM is located in engine compartment, below cover, just in front of battery, next to driver's side strut tower. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 110)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Red wire) at ECM electrical connector E2 and No. 17 (Brown wire) at ECM electrical connector E4. 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 E4 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.
3. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Black/Orange wire) at ECM electrical connector E2. 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 5.
4. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is defective, replace ignition switch. If ignition switch is okay, check for open and short in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 8 (Black/Orange wire) at ECM electrical connector E2. 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, just in front of strut tower. Repair wiring harness or electrical connectors as necessary.
5. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
6. 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 between battery and EFI fuse. See WIRING DIAGRAMS article.
7. Check for open in wiring harness and electrical connectors between EFI main relay and battery, and between EFI main relay and ECM. 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.
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, just in front of strut tower. 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 for open in wiring harness and electrical connectors between body ground and EFI main relay. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, test is complete. If wiring harness or electrical connector is defective, repair as necessary.

Corolla

1. Remove necessary components for access to Engine Control Module (ECM). See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. Remove bolts from ECM so electrical connectors can be accessed on ECM. Note ECM electrical connector terminals. (Scheme 111)and (Scheme 112).
3. Turn ignition on. On 3-speed A/T and M/T models, using voltmeter, check voltage between terminals No. 12 (Black wire) at ECM electrical connector E6 and No. 14 (Brown wire) at ECM electrical connector E4. On 4-speed A/T, using voltmeter, check voltage between terminals No. 16 (Black wire) at ECM electrical connector E10 and No. 17 (Brown wire) at ECM electrical connector E8. On all models, 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. 14 (Brown wire) at ECM electrical connector E4 and body ground on 3-speed A/T and M/T models, or terminal No. 17 (Brown wire) at ECM electrical connector E8 and body ground on 4-speed A/T models. See WIRING DIAGRAMS article. On all models, if wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
4. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. EFI main relay may also be referred to as EFI relay or F-HTR relay. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
5. Check for defective EFI fuse. EFI fuse may also be referred to as F-HTR 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.
6. Check for open in wiring harness and electrical connectors between EFI main relay and battery, and between EFI main relay and ECM. 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.
7. Check for defective IGN fuse. IGN fuse is located in fuse/relay 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.
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 ignition switch and EFI main relay, and between body ground and EFI main relay. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, test is complete. If wiring harness or electrical connector is defective, repair as necessary.

ECHO

1. Remove cover from Engine Control Module (ECM) for access to ECM electrical connectors. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 113)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 12 (Black/Red wire) at ECM electrical connector E4 and No. 14 (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. 14 (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 is defective, repair as necessary.
3. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
4. 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, 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.
5. Check for open in wiring harness and electrical connectors between EFI main relay and battery, and between EFI main relay and ECM. 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.
6. 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.
7. Check for open in wiring harness and electrical connectors between ignition switch and EFI main relay, and between body ground and EFI main relay. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, test is complete. If wiring harness or electrical connector is defective, repair as necessary.

Highlander

1. 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 114)
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-63407-S26453184222001020500000) 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 and electrical connectors as necessary.

MR2

1. Remove necessary components for access to Engine Control Module (ECM). ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. Remove bolts and disconnect ECM with electrical connectors from inside of firewall. Note ECM electrical connector terminals. (Scheme 115)
3. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black wire) at ECM electrical connector E2 and No. 17 (Brown wire) at ECM electrical connector E4. 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 E4 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.
4. Turn ignition off. Check for open and short in Black wire between EFI main relay and terminal No. 16 at ECM electrical connector E2. See WIRING DIAGRAMS article. EFI main relay is located in relay box on firewall at driver's side front corner of engine compartment. 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. 8 (Black/Red wire) at ECM electrical connector E2. 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 11.
6. Check for defective IG2 fuse. IG2 fuse is located in fuse/relay box at driver's side rear corner of engine compartment, just in front of strut tower. If IG2 fuse is okay, go to next step. If IG2 fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
7. Check operation of IG2 relay. See «IG2 RELAY»(ref-63407-S24753873762001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If IG2 relay operates properly, go to next step. If IG2 relay is defective, replace IG2 relay.
8. Check for defective AM2 fuse. AM2 fuse is located in fuse/relay box at driver's side rear 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.
9. 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.
10. Check for open in wiring harness and electrical connectors between battery and ignition switch, battery and IG2 relay, ignition switch and IG2 relay, and between IG2 relay and terminal No. 8 (Black/Red wire) at ECM electrical connector E2. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
11. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 21 (Gray 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. 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.
12. Check for defective EFI No. 1 fuse. EFI No. 1 fuse is located in fuse/relay box at driver's side rear corner of engine compartment, just in front of strut tower. 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.
13. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
14. Check for open and short in wiring harness and electrical connectors between terminal No. 21 (Gray 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 is defective, repair as necessary.
15. 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 and electrical connectors as necessary.

1. 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 116)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 4 (Black wire) at ECM electrical connector E8 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 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 E8 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.
3. Turn ignition off. Check for open and short in Black wire between EFI main relay and terminal No. 4 at ECM electrical connector E8. See WIRING DIAGRAMS article. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment. If wiring is okay, go to next step. If wiring is defective, repair as necessary.
4. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 9 (Black/White wire) at ECM electrical connector E10. 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 8.
5. Check for defective AM2 fuse. AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment. 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.
6. 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.
7. Check for open in wiring harness and electrical connectors between battery and ignition switch and between ignition switch and terminal No. 9 (Black/White wire) at ECM electrical connector E10. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
8. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 25 (Green/Red 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.
9. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment. 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.
10. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
11. Check for open and short in wiring harness and electrical connectors between terminal No. 25 (Green/Red wire) at ECM electrical connector E9 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.
12. 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 and electrical connectors as necessary.

1. Remove glove box for access to Engine Control Module (ECM). ECM is located near passenger's side kick panel, just below instrument panel. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 117)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Red or Light Green wire) at ECM electrical connector E8 and No. 17 (Brown wire) at ECM electrical connector E5. There are 2 different wiring harnesses used. Wire color at terminal No. 16 may vary according to wiring harness used. 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 is defective, repair as necessary.
3. Turn ignition off. Check for open and short in Black/Red or Light Green wire between EFI main relay and terminal No. 16 at ECM electrical connector E8. See WIRING DIAGRAMS article. EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery. If wiring is okay, go to next step. If wiring is defective, repair as necessary.
4. Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 2 (Black/Orange or White 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 9.
5. Check for defective IG2 fuse. IG2 fuse is located in fuse box behind driver's side of instrument panel. If IG2 fuse is okay, go to next step. If IG2 fuse is defective, repair short in wiring harness and components connected to IG2 fuse. See WIRING DIAGRAMS article.
6. Check for defective AM2 fuse. AM2 fuse is located in fuse/relay box at driver's side front corner of engine compartment. 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.
7. 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.
8. Check for open in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and terminal No. 2 (Black/Orange or White wire) at ECM electrical connector E8. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
9. Ensure ignition is on. Using voltmeter, check voltage between body ground and terminal No. 8 (Green/White or White 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.
10. 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. 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.
11. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
12. Check for open in wiring harness and electrical connectors between EFI main relay, EFI No. 1 fuse and battery. 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.
13. Check for open and short in wiring harness and electrical connectors between terminal No. 8 (Green/White or White 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, test is complete. If wiring harness or electrical connector is defective, repair as necessary.

Tacoma

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 118)
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 is defective, repair as necessary.
3. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) 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.
4. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver's side front corner of engine compartment, next to 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.
5. Check for open in wiring harness and electrical connectors between EFI main relay and battery, and between EFI main relay and ECM. 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.
6. Check for defective IGN fuse. IGN fuse is located in fuse/relay 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 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.
8. Check for open in wiring harness and electrical connectors between ignition switch and EFI main relay, and between EFI main relay and body ground. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, test is complete. If wiring harness or electrical connector is defective, repair as necessary.

Note. On Camry CNG models, fuel injectors are actuated by 150 volts for approximately 100 milliseconds when engine is first started. Voltage has been increased to 150 volts by voltage booster circuit incorporated into Engine Control Module (ECM).

Scheme 94

1. Check that wiring harness and electrical connectors for fuel injectors are properly connected. If wiring harness and electrical connectors for fuel injectors are properly connected, go to next step. If wiring harness and electrical connectors for fuel injectors are not properly connected, repair as necessary. Drive vehicle to confirm that no cylinders are misfiring.
2. Check that vacuum hoses are properly connected and that no vacuum hoses are damaged. If vacuum hoses are properly connected and no vacuum hoses are damaged, go to next step. If vacuum hoses are not properly connected or vacuum hoses are damaged, repair as necessary. Drive vehicle to confirm that no cylinders are misfiring.
3. Note which cylinder is misfiring. Check spark plug and for spark on misfiring cylinder. See SPARK TEST under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article. If spark plug is okay and proper spark exist at misfiring cylinder, go to next step. If sparks plug is defective or proper spark does not exist at misfiring cylinder, replace components or repair ignition system as necessary.
4. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 108)
5. Turn ignition on. Using voltmeter, check voltage between body ground and appropriate terminal at ECM electrical connector E7 for misfiring cylinder. See «ECM TERMINAL #10 TO #40 IDENTIFICATION FOR FUEL INJECTORS»(ref-63407-S06544811122001020500000) table. These are the #10 to #40 terminals for fuel injectors at ECM. Voltage should be 9-14 volts. Using oscilloscope, check fuel injector signal wave pattern and fuel injector duration signal wave pattern with engine idling at appropriate terminal at ECM electrical connector E7 for misfiring cylinder. Fuel injector signal wave pattern and fuel injector duration signal wave pattern should be properly displayed with 100 millisecond intervals. (Scheme 94) If voltage is not within specification, or fuel injector signal wave pattern or fuel injector duration signal wave pattern are not okay, go to next step. If voltage is within specification, and fuel injector signal wave pattern and fuel injector duration signal wave pattern are okay, go to step 9. ECM TERMINAL #10 TO #40 IDENTIFICATION FOR FUEL INJECTORS Fuel Injector Location ECM Connector ECM Terminal No. (Wire Color) Cyl. No. 1 E7 6 (Black/White) Cyl. No. 2 E7 7 (Black/Red) Cyl. No. 3 E7 8 (Red) Cyl. No. 4 E7 9 (Orange)
6. Ensure ignition is on. Using voltmeter, check voltage between body ground and appropriate terminal at ECM electrical connector E7 for misfiring cylinder. See «ECM TERMINAL #10+ TO #40+ IDENTIFICATION FOR FUEL INJECTORS»(ref-63407-S02711241992001020500000) table. These are the #10+ to #40+ terminals for fuel injectors at ECM. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, replace ECM. ECM TERMINAL #10+ TO #40+ IDENTIFICATION FOR FUEL INJECTORS Fuel Injector Location ECM Connector ECM Terminal No. (Wire Color) Cyl. No. 1 E7 2 (Blue) Cyl. No. 2 E7 3 (Brown) Cyl. No. 3 E7 4 (Green) Cyl. No. 4 E7 5 (White)
7. Turn ignition off. Disconnect electrical connector at fuel injector on misfiring cylinder. Using ohmmeter, check resistance between electrical terminals on fuel injector. Resistance should be 1.40-2.00 ohms at 68°F (20°C). If resistance is within specification, reinstall electrical connector on fuel injector and go to next step. If resistance is not within specification, replace fuel injector.
8. Check for open and short in wiring harness and connectors between fuel injector and ECM. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, test is complete. If wiring harness or electrical connector is defective, repair as necessary.
9. Check operation of fuel rail fuel shutoff valve, fuel pressure regulator fuel shutoff valve and fuel tank fuel shutoff valve. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION in appropriate SELF-DIAGNOSTICS article. If all fuel shutoff valves operate properly, go to next step. If any fuel shutoff valve does not operate properly, replace or repair as necessary.
10. Check fuel injector operation. See «FUEL CONTROL»(ref-63407-S33520042872001020500000) under FUEL SYSTEMS. If fuel injector operates properly, go to next step. If fuel injector does not operate properly, replace fuel injector.
11. Check EGR system operation by performing system check. See «EXHAUST GAS RECIRCULATION SYSTEM»(ref-63407-S21295567442001020500000) under EMISSION SYSTEMS & SUB-SYSTEMS. If EGR system operates properly, go to next step. If EGR system does not operate properly, repair EGR system as necessary.
12. Check Engine Coolant Temperature (ECT) sensor and Manifold Absolute Pressure (MAP) sensor. See «ENGINE COOLANT TEMPERATURE SENSOR»(ref-63407-S28361987362001020500000) and «MANIFOLD ABSOLUTE PRESSURE SENSOR»(ref-63407-S01737000892001020500000) under ENGINE SENSORS & SWITCHES. If ECT sensor and MAP sensor operate properly, go to next step. If ECT sensor or MAP sensor does not operate properly, replace as necessary.
13. Check engine compression. See MECHANICAL INSPECTION under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article. If engine compression is within specification, go to next step. If engine compression is not within specification, repair engine as necessary.
14. Check valve clearance. See VALVE CLEARANCE under ENGINE MECHANICAL in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article. If valve clearance is within specification, go to next step. If valve clearance is not within specification, adjust valve clearance as necessary.
15. Check valve timing. See appropriate article in ENGINES. If valve timing is correct, test is complete. If valve timing is not correct, repair as necessary.

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

Testing information is not available from manufacturer.

FUEL PIPE FUEL PRESSURE SENSOR CIRCUIT

Note. Fuel pipe fuel pressure sensor may also be referred to as fuel pressure sensor (fuel pipe).

Scheme 95

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 108)
2. Turn ignition on. Using voltmeter, check voltage between VC and E2 terminals at ECM for fuel pipe fuel pressure sensor. See «ECM TERMINAL IDENTIFICATION FOR FUEL PIPE FUEL PRESSURE SENSOR»(ref-63407-S16736921242001020500000) table. ECM TERMINAL IDENTIFICATION FOR FUEL PIPE FUEL PRESSURE SENSOR ECM Terminal ECM Connector ECM Terminal No. (Wire Color) E2 E6 18 (Brown Wire) PCNG1 E6 11 (Green/Red Wire) VC E6 2 (Yellow)
3. Voltage should be 4.5-5.5 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.
4. Ensure ignition is on. Using voltmeter, check voltage between PCNG1 and E2 terminals at ECM for fuel pipe fuel pressure sensor. See «ECM TERMINAL IDENTIFICATION FOR FUEL PIPE FUEL PRESSURE SENSOR»(ref-63407-S16736921242001020500000) table.
5. Voltage should be as specified in relation fuel gauge reading. See «FUEL PIPE FUEL PRESSURE SENSOR VOLTAGE SPECIFICATIONS»(ref-63407-S32309261972001020500000) table. FUEL PIPE FUEL PRESSURE SENSOR VOLTAGE SPECIFICATIONS Fuel Gauge Reading Voltage @ 68°F (20°C) Full 3.3 3/4 2.7 1/2 2.0 1/4 1.3
6. If voltage is not within specification, go to next step. If voltage is 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.
7. Check for open and short in wiring harness and electrical connectors between ECM and fuel pipe fuel pressure sensor. See WIRING DIAGRAMS article. Fuel pipe fuel pressure sensor is located near fuel pressure regulator located in fuel line between fuel tank and fuel rail, just below brake booster. (Scheme 95)
8. If wiring harness and electrical connectors are okay, replace fuel pipe fuel pressure sensor. See FUEL PIPE FUEL PRESSURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. If wiring harness or electrical connector is defective, repair as necessary.

FUEL PUMP CONTROL CIRCUIT

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 - 4-CYLINDER article. If fuel pump does not operate when using hand-held tester, go to step 5. If fuel pump operates when using hand-held tester, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Remove necessary components for access to Engine Control Module (ECM). See «ENGINE CONTROL MODULE LOCATION»(ref-63407-S20016928132001020500000) table.
4. Note ECM terminals. (Scheme 109)- (Scheme 118). Turn ignition on. Momentarily connect jumper wire between body ground and FC terminal at ECM and listen for fuel pump operating sound. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL»(ref-63407-S26957518932001020500000) table. On Camry gasoline models and Camry Solara, feel for fuel pressure in fuel inlet line at fuel filter when fuel inlet line is pinched closed. On Celica, Corolla, ECHO, Highlander, MR2, Prius and RAV4, feel for fuel pressure in fuel inlet line at end of fuel rail when fuel inlet line is pinched closed. On Tacoma, feel for fuel pressure in fuel return line from fuel pressure regulator when fuel return line is pinched closed. On all models, if fuel pump does not operate when jumper wire was connected, go to next step. If fuel pump operates when jumper wire was connected, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
5. Check ECM power source circuit. See «ENGINE CONTROL MODULE POWER SOURCE CIRCUIT»(ref-63407-S19590243722001020500000). If ECM power source circuit is okay, go to next step. If ECM power source circuit is defective, repair as necessary.
6. Check circuit opening relay. See «CIRCUIT OPENING RELAY»(ref-63407-S04619833102001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. If circuit opening relay is okay, go to next step. If circuit opening relay is defective, replace circuit opening relay.
7. Remove necessary components for access to ECM if not previously done. See «ENGINE CONTROL MODULE LOCATION»(ref-63407-S20016928132001020500000) table. ENGINE CONTROL MODULE LOCATION Model (1) Location Camry Gasoline Models & Camry Solara Behind Glove Box Celica In Engine Compartment, Below Cover, Just In Front Of Battery, Next To Driver's Side Strut Tower Corolla Behind Stereo On Instrument Panel, Just In Front Of Center Console ECHO & Highlander Behind Glove Box MR2 On Inside Of Firewall, Directly Behind Driver's Seat & Luggage Compartment Prius Behind Glove Box RAV4 Near Passenger's Side Kick Panel, Just Below Instrument Panel Tacoma Behind Glove Box (1) For illustration of ECM location, see THEORY & OPERATION article.
8. Note ECM terminals. (Scheme 109)- (Scheme 118). Turn ignition on. Using voltmeter, check voltage between body ground and FC terminal at ECM. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL»(ref-63407-S26957518932001020500000) table. ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL Application ECM Connector ECM Terminal No. (Wire Color) Camry Gasoline Models & Camry Solara E7 3 (Green/Red) Celica E2 3 (Green/Red) Corolla 3-Speed A/T & M/T E6 14 (Green/Red) 4-Speed A/T E10 3 (Green/Red) ECHO E4 14 (Green) Highlander E5 3 (Green/Red) MR2 E2 3 (Green/Red) Prius E8 9 (Green/Red) RAV4 E8 (1) 3 (Green/Red Or White) Tacoma E6 6 (White/Blue) (1) There are 2 different wiring harnesses used. Wire color at designated terminal may vary according to wiring harness used.
9. Voltage should be 9-14 volts. If voltage is within specification, go to next step. On Camry gasoline models, Camry Solara, Highlander, MR2 and RAV4, if voltage is not within specification, check for open in wiring harness and connectors between ECM and circuit opening relay, and between ignition switch and circuit opening relay. See WIRING DIAGRAMS article. For EFI main relay location, see «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. On Celica, Corolla, ECHO, Prius and Tacoma, if voltage is not within specification, check for open in wiring harness and connectors between ECM and circuit opening relay, and between EFI main relay and circuit opening relay. See WIRING DIAGRAMS article. For EFI main relay location, see «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. On all models, if wiring harness or electrical connector is defective, repair as necessary.
10. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-63407-S31016737032001020500000) 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.
11. 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. On Camry gasoline models, Camry Solara, Highlander, MR2 and RAV4, also check for open in wiring harness and electrical connectors between circuit opening relay and EFI main relay. See WIRING DIAGRAMS article. For EFI main relay location, see «EFI MAIN RELAY»(ref-63407-S26453184222001020500000) under MODULES, MOTORS, RELAYS & SOLENOIDS. On all models, if wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
12. 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 Camry gasoline models, Camry Solara, Highlander, MR2 and RAV4, 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.

FUEL TANK FUEL TEMPERATURE SENSOR CIRCUIT

Note. Fuel tank fuel temperature sensor may also be referred to as fuel temperature sensor (fuel tank).

Scheme 96

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 108)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 18 (Brown wire) at ECM electrical connector E6 and No. 10 (Light Green/Black wire) at ECM electrical connector E5. This is the E2 and THCNG1 terminals at ECM.
3. Voltage should be as specified in relation to the temperature. See «FUEL TANK FUEL TEMPERATURE SENSOR VOLTAGE SPECIFICATIONS»(ref-63407-S07043831272001020500000) table. FUEL TANK FUEL TEMPERATURE SENSOR VOLTAGE SPECIFICATIONS Temperature Voltage -22°F (-30°C).56-.45 77°F (25°C) 3.39-3.29 104°F (40°C) 4.00-3.90 212°F (100°C) 4.85-4.82
4. If voltage is not within specification, go to next step. If voltage is within specification, check for an intermittent problem in wiring harness and electrical connectors between ECM and fuel tank fuel temperature sensor. Fuel tank fuel temperature sensor is located on end of fuel tank behind rear seat, near fuel tank fuel shutoff valve. (Scheme 96)
5. Check fuel tank fuel temperature sensor. See «FUEL TANK FUEL TEMPERATURE SENSOR»(ref-63407-S31793556492001020500000) under ENGINE SENSORS & SWITCHES. If fuel tank fuel temperature sensor is okay, go to next step. If fuel tank fuel temperature sensor is defective, replace fuel tank fuel temperature sensor.
6. Check for open and short in wiring harness and electrical connectors between ECM and fuel tank fuel temperature sensor. See WIRING DIAGRAMS article. If wiring harness or electrical connector is 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.

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.

Scheme 97

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)and (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. 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 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-63407-S09426178882001020500000) table. 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. (Scheme 97) For ECM electrical connector terminal identification (Scheme 108)and (Scheme 109). NOTE: On Camry gasoline models and Camry Solara, junction connectors J6 and J7 may also be referred to as junction connectors J7 and J8.
4. If wiring harness or electrical connector is 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 Camry gasoline models and Camry Solara 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 108)and (Scheme 109). Using voltmeter, check voltage between body ground and STA terminal (starter signal wire) at ECM with ignition switch in START position and engine cranking. See «ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA)»(ref-63407-S09426178882001020500000) table. ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA) Application ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E4 7 (Gray) Gasoline Models 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 in starter signal wire and electrical connectors between STA terminal at ECM and junction connectors J6 and J7. Junction connectors J6 and J7 are located behind driver's side of instrument panel, near fuse/relay box. (Scheme 97) NOTE: On Camry gasoline models and Camry Solara, junction connectors J6 and J7 may also be referred to as junction connectors J7 and J8.
8. If wiring harness or electrical connector is 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 Camry gasoline models and Camry Solara, 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.

Celica & ECHO

Testing information is not available from manufacturer.

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. 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 in Black/White wire (starter signal wire) and electrical connectors between starter relay and terminal No. 11 at Engine Control Module (ECM) electrical connector E6 on 3-speed A/T and M/T models, or terminal No. 11 at ECM electrical connector E9 on 4-speed A/T models. See WIRING DIAGRAMS article. ECM is located behind stereo on instrument panel, just in front of center console. 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, just in front of strut tower and may be marked as ST relay. For ECM electrical connector terminal identification (Scheme 111)and (Scheme 112).
4. If wiring harness or electrical connector is 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 necessary components for access to Engine Control Module (ECM). See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Remove bolts from ECM so electrical connectors can be accessed on ECM.
6. Note ECM electrical connector terminals. (Scheme 111)and (Scheme 112). On 3-speed A/T and M/T models, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E6 with ignition switch in START position and engine cranking. On 4-speed A/T models, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E9 with ignition switch in START position and engine cranking. On all models, this is the STA terminal at ECM.
7. 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.
8. Check for open in Black/White wire and electrical connectors between starter relay and terminal No. 11 at ECM electrical connector E6 on 3-speed A/T and M/T models, or terminal No. 11 at ECM electrical connector E9 on 4-speed A/T models. See WIRING DIAGRAMS article. This is the starter signal wire. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower and may be marked as ST relay.
9. If wiring harness or electrical connector is 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.

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. 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 or short in Blue wire and electrical connectors between starter fuse and terminal No. 16 at Engine Control Module (ECM) electrical connector E7. 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 114)
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.
6. Note ECM electrical connector terminals. (Scheme 114) Using voltmeter, check voltage between body ground and terminal No. 16 (Blue wire) at ECM electrical connector E7 with ignition switch in START position and engine cranking. (Scheme 114) 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 or short in Blue wire and electrical connectors between starter fuse and terminal No. 16 at ECM electrical connector E7. 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 104) 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. 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 wire between starter relay and starter fuse, defective starter fuse, and for open or short in Black wire and electrical connectors between starter fuse and terminal No. 11 at Engine Control Module (ECM) electrical connector E3. 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 rear corner of engine compartment, just in front of strut tower and may be marked as ST relay and ST fuse. ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. For illustration of ECM location, see THEORY & OPERATION article. To remove components for access to ECM, see ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. For ECM electrical connector terminal identification (Scheme 115)
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 necessary components for access to Engine Control Module (ECM). ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Remove bolts and disconnect ECM with electrical connectors from inside of firewall.
6. Note ECM electrical connector terminals. (Scheme 115) Using voltmeter, check voltage between body ground and terminal No. 11 (Black wire) at ECM electrical connector E3 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 wire between starter relay and starter fuse, defective starter fuse, and for open or short in Black wire and electrical connectors between starter relay and terminal No. 11 at ECM electrical connector E3. 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 rear corner of engine compartment, just in front of strut tower and may be marked as ST relay and ST 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. 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.

Note. Testing information is not available from manufacturer.

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 106) 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. 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 between starter relay and starter fuse, defective starter fuse, and for open or short in Black/Red or White wire and electrical connectors between starter fuse and terminal No. 7 (Black/Red or White wire) at Engine Control Module (ECM) electrical connector E8. There are 2 different wiring harnesses used. Wire color at between starter fuse and terminal No. 7 at ECM may vary according to wiring harness used. 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 and may be marked as ST relay and ST fuse. ECM is located near passenger's side kick panel, just below instrument panel. For illustration of ECM location, see THEORY & OPERATION article. For ECM electrical connector terminal identification (Scheme 117)
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.
6. Note ECM electrical connector terminals (Scheme 117) Using voltmeter, check voltage between body ground and terminal No. 7 (Black/Red or White wire) at ECM electrical connector E8 ignition switch in START position and engine cranking. There are 2 different wiring harnesses used. Wire color at terminal No. 7 at ECM may vary according to wiring harness used. 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 between starter relay and starter fuse, defective starter fuse, and for open or short in Black/Red or White wire and electrical connectors between starter fuse and terminal No. 7 at ECM electrical connector E8. 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 and may be marked as ST relay and ST 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. 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 107) 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. 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 in Black/White wire between park/neutral position switch (A/T) or clutch start switch (M/T) and terminal No. 7 at Engine Control Module (ECM) electrical connector E5. This is the starter signal circuit to ECM. See WIRING DIAGRAMS article. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. For ECM electrical connector terminal identification (Scheme 118) Park/neutral position switch is located on side of transmission and clutch start switch is located near top of clutch pedal.
4. If wiring harness or electrical connector is 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.
6. Note ECM electrical connector terminals. (Scheme 118) Using voltmeter, check voltage 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 in Black/White wire between park/neutral position switch (A/T) or clutch start switch (M/T) and terminal No. 7 at ECM electrical connector E5. This is the starter signal circuit to ECM. See WIRING DIAGRAMS article. Park/neutral position switch is located on side of transmission and clutch start switch is located near top of clutch pedal.
8. If wiring harness or electrical connector is 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.

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

Scheme 103

Scheme 104

Scheme 105

Scheme 106

Scheme 107

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 108)- (Scheme 118).

Scheme 108

Scheme 109

Scheme 110

Scheme 111

Scheme 112

Scheme 113

Scheme 114

Scheme 115

Scheme 116

Scheme 117

Scheme 118

2001 MR2 With Sequential Manual Transaxle

There are 2 types of manual transaxles used. The sequential manual transaxle may be identified by the shift lever pattern which consists of "R", "N", "S" and "+" in place of the conventional type shift lever pattern and there is no clutch pedal. For testing of accelerator pedal position sensor, see THROTTLE BODY under IDLE CONTROL SYSTEMS.

Scheme 119

1. Disconnect electrical connector at accelerator pedal position sensor. Accelerator pedal position sensor is located near top of accelerator pedal. (Scheme 119)
2. Using ohmmeter, check resistance between VCP1 and EP1 terminals, and between VCP2 and EP2 terminals on accelerator pedal position sensor. (Scheme 119) Resistance should be 1500-6000 ohms at 68°F (20°C). Replace accelerator pedal position sensor if resistance is not within specification.

Scheme 120

1. Disconnect electrical connector for A/C compressor lock sensor. A/C compressor lock sensor is located near front of A/C compressor with electrical connector located near generator. (Scheme 120) This is the electrical connector for A/C compressor lock sensor and magnetic clutch on front of A/C compressor.
2. Using ohmmeter, check resistance between terminals No. 1 and 2 on electrical connector for A/C compressor lock sensor. (Scheme 120) Resistance should be 65-125 ohms at 68°F (20°C). Replace A/C compressor lock sensor if resistance is not within specification. It may be necessary to replace A/C compressor along with A/C compressor lock sensor as an assembly. Consult parts department for parts availability.

Scheme 121

Scheme 122

Scheme 123

Scheme 124

1. Disconnect electrical connector for A/C compressor lock sensor and magnetic clutch on front of A/C compressor. This is the electrical located near front of A/C compressor.
2. Using ohmmeter, check resistance between terminals No. 1 and 2 on electrical connector for A/C compressor lock sensor and magnetic clutch. (Scheme 121)- (Scheme 124). Resistance should be 165-205 ohms at 68°F (20°C). Replace A/C compressor lock sensor if resistance is not within specification. It may be necessary to replace A/C compressor along with A/C compressor lock sensor as an assembly. Consult Toyota parts department for parts availability.

Scheme 125

1. Remove A/C evaporator temperature sensor. A/C evaporator temperature sensor is located in evaporator case, next to evaporator core. For servicing of A/C evaporator temperature sensor, see appropriate article in AIR CONDITIONING & HEATING.
2. Place probe end of A/C evaporator temperature sensor with thermometer in container of water. Using ohmmeter, check resistance between electrical terminals on A/C evaporator temperature sensor while using ice to cool water. Ensure ice does not contact A/C evaporator temperature sensor.
3. Check that resistance is within specification in relation to water temperature. (Scheme 125) Replace A/C evaporator temperature if resistance is not within specification at specified temperature.

AIR/FUEL SENSOR

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

Scheme 126

1. Heated A/F sensor is mounted on exhaust manifold above catalytic converter. 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 for A/F sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 126) Replace A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C).

Scheme 127

Scheme 128

1. Two heated A/F sensors are used. Heated A/F sensors are mounted on exhaust manifold above catalytic converters. A/F sensor for cylinders No. 1 and 4 is referred to as bank No. 1 sensor No. 1. A/F sensor for cylinders No. 2 and 3 is referred to as bank No. 2 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 for A/F sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 127)and (Scheme 128). Replace A/F sensor if resistance is not within specification. See «A/F SENSOR HEATER RESISTANCE»(ref-63407-S38773748322000122200000) table. A/F SENSOR HEATER RESISTANCE Application & Temperature Ohms Highlander 68°F (20°C) 1.8-3.4 932°F (500°C) 5.0-7.5 RAV4 68°F (20°C).8-1.4 1472°F (800°C) 1.8-3.2

Scheme 129

1. Heated A/F sensor is mounted on exhaust pipe in front of catalytic converter. 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 for A/F sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 129) 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).

AIRFLOW METER

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

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

1. Remove airflow meter. See AIRFLOW METER under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. Using ohmmeter, check resistance between terminals E2 and THA on airflow meter. (Scheme 130)- (Scheme 133). Resistance should be within specification in relation to temperature. See «AIRFLOW METER RESISTANCE»(ref-63407-S26787726352001020500000) table. Replace airflow meter if resistance is not within specification. AIRFLOW METER RESISTANCE Application & Temperature Ohms Celica & ECHO -4°F (-20°C) 13,600-18,400 68°F (20°C) 2210-2690 140°F (60°C) 490-670 Corolla -4°F (-20°C) 13,600-18,400 68°F (20°C) 2200-2700 140°F (60°C) 500-700 Highlander -4°F (-20°C) 13,600-18,400 68°F (20°C) 2210-2690 140°F (60°C) 493-667 MR2, Prius & RAV4 -4°F (-20°C) 13,600-18,400 68°F (20°C) 2210-2690 140°F (60°C) 490-670 Tacoma -4°F (-20°C) 10,000-20,000 32°F (0°C) 4000-7000 68°F (20°C) 2000-3000 104°F (40°C) 900-1300 140°F (60°C) 400-700 176°F (80°C) 200-400
3. To test airflow meter operation, install electrical connector on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. (Scheme 132)and (Scheme 134) - (Scheme 136). Turn ignition on.
4. Apply air into airflow meter and note voltage reading. (Scheme 132)and (Scheme 134) - (Scheme 136). While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Turn ignition off. Remove voltmeter.

Scheme 130

Scheme 131

Scheme 132

Scheme 133

Scheme 134

Scheme 135

Scheme 136

BRAKELIGHT SWITCH

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

Camry CNG & Gasoline Models, Celica, Corolla, MR2, RAV4 & Tacoma

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on brakelight switch. (Scheme 137)
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 137

Camry Solara & Highlander

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on brakelight switch. (Scheme 138)
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 138

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on brakelight switch. (Scheme 139)
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. Adjust or replace brakelight switch if operation is not as described.

Scheme 139

CAMSHAFT POSITION SENSOR

For testing camshaft position sensor, see CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article.

CRANKSHAFT POSITION SENSOR

For testing crankshaft position sensor, see CRANKSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article.

Tacoma 2.7L 3RZ-FE

1. EGR gas temperature sensor is located near EGR valve. Remove EGR gas temperature sensor. See EGR GAS TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
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-63407-S21292422812001020500000) table. Replace EGR gas temperature sensor if resistance is not within specification. Reinstall EGR gas temperature sensor.

EGR GAS TEMPERATURE SENSOR RESISTANCE

Camry CNG & Gasoline Models, Camry Solara, Highlander, MR2, Prius, RAV4 & Tacoma

1. Ensure ignition is off. Disconnect electrical connector from Engine Coolant Temperature (ECT) sensor. See «ENGINE COOLANT TEMPERATURE SENSOR LOCATION»(ref-63407-S39356165752001020500000) table. Remove ECT sensor. See ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER 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 141) Replace ECT sensor if resistance is not within specification.

Celica, Corolla & ECHO

1. Ensure ignition is off. Disconnect electrical connector from Engine Coolant Temperature (ECT) sensor. See «ENGINE COOLANT TEMPERATURE SENSOR LOCATION»(ref-63407-S39356165752001020500000) table. Remove ECT sensor. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between electrical terminals No. 1 and 2 on ECT sensor. (Scheme 140) Heat water and note that resistance is within specification in relation to temperature. (Scheme 141) Replace ECT sensor if resistance is not within specification.

ENGINE COOLANT TEMPERATURE SENSOR LOCATION

Scheme 140

Scheme 141

FUEL PIPE FUEL PRESSURE SENSOR

Note. Fuel pipe fuel pressure sensor may also be referred to as fuel pressure sensor (fuel pipe). Manufacturer does not provide individual component testing for fuel pipe fuel pressure sensor. Manufacturer lists testing procedure for supply voltage and output voltage for fuel pipe fuel pressure sensor.

Scheme 142

1. To test fuel pipe fuel pressure sensor supply voltage, disconnect electrical connector at fuel pipe fuel pressure sensor. Fuel pipe fuel pressure sensor is located near fuel pressure regulator located in fuel line between fuel tank and fuel rail, just below brake booster. (Scheme 142)
2. Turn ignition on. Using voltmeter, check fuel pipe fuel pressure sensor supply voltage between terminals GND and VC on electrical connector for fuel pipe fuel pressure sensor. (Scheme 142) Fuel pipe fuel pressure sensor supply voltage should be 4.5-5.5 volts at 68°F (20°C).
3. Turn ignition off. Reinstall electrical connector on fuel pipe fuel pressure sensor. If fuel pipe fuel pressure sensor supply voltage is within specification, go to next step. If fuel pipe fuel pressure sensor supply voltage is not within specification, check wiring circuit to fuel pipe fuel pressure sensor. See WIRING DIAGRAMS article.
4. To test fuel pipe fuel pressure sensor output voltage, remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article.
5. Turn ignition on. Note ECM electrical connector terminals. (Scheme 108) Using voltmeter, check fuel pipe fuel pressure sensor output voltage between terminals No. 11 (Green/Red wire) at ECM electrical connector E6 and No. 18 (Brown wire) at ECM electrical connector E6. This is the PCNG1 and E2 terminals at ECM.
6. Fuel pipe fuel pressure sensor output voltage should be as specified in relation fuel gauge reading. See «FUEL PIPE FUEL PRESSURE SENSOR OUTPUT VOLTAGE SPECIFICATIONS»(ref-63407-S31011689662001020500000) table. Turn ignition off. If fuel pipe fuel pressure sensor output voltages are as not as specified and wiring circuit is okay, it may be necessary to replace fuel pipe fuel pressure sensor. FUEL PIPE FUEL PRESSURE SENSOR OUTPUT VOLTAGE SPECIFICATIONS Fuel Gauge Reading Approximate Voltage @ 68°F (20°C) Full 2.8 3/4 2.4 1/2 1.8 1/4 1.3

FUEL RAIL FUEL PRESSURE SENSOR

Note. Fuel rail fuel pressure sensor may also be referred to as delivery pipe fuel pressure sensor or fuel pressure sensor (delivery pipe). Manufacturer does not provide individual component testing for fuel rail fuel pressure sensor. Manufacturer lists testing procedure for supply voltage and output voltage for fuel rail fuel pressure sensor.

Scheme 143

1. To test fuel rail fuel pressure sensor supply voltage, disconnect electrical connector at fuel rail fuel pressure sensor. Fuel rail fuel pressure sensor is located on end of fuel rail, near discharge valve. (Scheme 143)
2. Turn ignition on. Using voltmeter, check fuel rail fuel pressure sensor supply voltage between terminals GND and VC on electrical connector for fuel rail fuel pressure sensor. (Scheme 143) Fuel rail fuel pressure sensor supply voltage should be 4.5-5.5 volts at 68°F (20°C). Turn ignition off. Reinstall electrical connector on fuel rail fuel pressure sensor. If fuel rail fuel pressure sensor supply voltage is within specification, go to next step. If fuel rail fuel pressure sensor supply voltage is not within specification, check wiring circuit to fuel rail fuel pressure sensor. See WIRING DIAGRAMS article.
3. To test fuel rail fuel pressure sensor output voltage, remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article.
4. Turn ignition on. Note ECM electrical connector terminals. (Scheme 108) Using voltmeter, check fuel rail fuel pressure sensor output voltage between terminals No. 10 (Green/Black wire) at ECM electrical connector E6 and No. 18 (Brown wire) at ECM electrical connector E6. This is the PCNG2 and E2 terminals at ECM.
5. Fuel rail fuel pressure sensor output voltage should be 3.1-3.6 volts at 68°F (20°C). Turn ignition off. If fuel rail fuel pressure sensor output voltage is not as specified and wiring circuit is okay, it may be necessary to replace fuel rail fuel pressure sensor.

FUEL RAIL FUEL TEMPERATURE SENSOR

Note. Fuel rail fuel temperature sensor may also be referred to as delivery pipe fuel temperature sensor or fuel temperature sensor (delivery pipe).

1. Remove fuel rail fuel temperature sensor. See FUEL RAIL FUEL TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. Place probe end of fuel rail fuel temperature sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on fuel rail fuel temperature sensor.
3. Heat water and note that resistance is within specification in relation to temperature. See «FUEL RAIL FUEL TEMPERATURE SENSOR RESISTANCE»(ref-63407-S35244256512001020500000) table. Replace fuel rail fuel temperature sensor if resistance is not within specification. FUEL RAIL FUEL TEMPERATURE SENSOR RESISTANCE Temperature Ohms -4°F (-20°C) 13,900-16,300 68°F (20°C) 2320-2590 176°F (80°C) 310-326

FUEL TANK FUEL TEMPERATURE SENSOR

Note. Fuel tank fuel temperature sensor may also be referred to as fuel temperature sensor (fuel tank).

1. Remove fuel tank fuel temperature sensor. See FUEL TANK FUEL TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. Place probe end of fuel tank fuel temperature sensor and thermometer in container of water. Attach ohmmeter between electrical terminals No. 3 and 4 on electrical connector for fuel tank fuel temperature sensor. (Scheme 144)
3. Heat water and note that resistance is within specification in relation to temperature. See «FUEL TANK FUEL TEMPERATURE SENSOR RESISTANCE»(ref-63407-S39694484572001020500000) table. Replace fuel tank fuel temperature sensor if resistance is not within specification. FUEL TANK FUEL TEMPERATURE SENSOR RESISTANCE Temperature Ohms -22°F (-30°C) 80,000-100,000 77°F (25°C) 4800-5200 104°F (40°C) 2510-2810 212°F (100°C) 300-370

Scheme 144

Scheme 145

1. A heated Air/Fuel (A/F) sensor is mounted on exhaust manifold above catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63407-S23346034662001020500000). Another heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor. Electrical connector is a Dark Gray 4-pin electrical connector located below passenger's side front seat and carpet, near center console. (Scheme 145)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 145) 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 146

Scheme 147

1. Two heated oxygen sensors are used. One heated oxygen sensor is mounted on exhaust pipe in front of front catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 1, or front oxygen sensor. Another heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. Electrical connector for bank No. 1 sensor No. 1 is a 4-pin electrical connector located near front of center console. (Scheme 146) Electrical connector for bank No. 1 sensor No. 2 is a Gray, 4-pin electrical connector located below passenger's side front seat and carpet, near center console. (Scheme 147)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 146)and (Scheme 147). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists with either 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 oxygen sensor is mounted on exhaust pipe in front of catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 1, or front oxygen sensor. Another heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. Electrical connector for bank No. 1 sensor No. 1 is a Dark Gray 4-pin electrical connector located near exhaust manifold. (Scheme 148) Electrical connector for bank No. 1 sensor No. 2 is a Dark Gray 4-pin electrical connector located below passenger's side front seat and carpet, near center console. (Scheme 149)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 148)and (Scheme 149). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists with either 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 148

Scheme 149

1. A heated oxygen sensor is mounted on exhaust pipe in front of catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 1, or front oxygen sensor. Another heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. Electrical connector for bank No. 1 sensor No. 1 is a Gray 4-pin electrical connector located near exhaust pipe. (Scheme 150) Electrical connector for bank No. 1 sensor No. 2 is a Gray 4-pin electrical connector located below passenger's side front seat and carpet, near center console. (Scheme 151)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 150)and (Scheme 151). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists with either 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 150

Scheme 151

Scheme 152

1. Two heated Air/Fuel (A/F) sensors are used. Heated A/F sensors are mounted on exhaust manifold above catalytic converter. For testing of A/F sensors, see «AIR/FUEL SENSOR»(ref-63407-S23346034662001020500000). Two heated oxygen sensors are also used. Heated oxygen sensors are mounted on exhaust manifold below catalytic converters. Heated oxygen sensor for cylinders No. 1 and 4 is referred to as bank No. 1 sensor No. 2. Heated oxygen sensor for cylinders No. 2 and 3 is referred to as bank No. 2 sensor No. 2.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 152) Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
3. If problem exists in either 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. Three heated oxygen sensors are used with 2 being mounted on exhaust manifold, above catalytic converters, and one on exhaust pipe below catalytic converters. Heated oxygen sensor for cylinders No. 1 and 4 is referred to as bank No. 1 sensor No. 1. Heated oxygen sensor for cylinders No. 2 and 3 is referred to as bank No. 2 sensor No. 1. Heated oxygen sensor mounted on exhaust pipe is referred to as bank No. 1 sensor No. 2.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. (Scheme 153) - (Scheme 155). Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 153)- (Scheme 155). 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).
3. If problem exists with any 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 153

Scheme 154

Scheme 155

1. A heated oxygen sensor is mounted on exhaust pipe in front of catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 1, or front oxygen sensor. Another heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This heated oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. Electrical connector for bank No. 1 sensor No. 1 is a Dark Gray 4-pin electrical connector located near exhaust manifold. (Scheme 156) Electrical connector for bank No. 1 sensor No. 2 is a 4-pin electrical connector located below passenger's side carpet, near center console. (Scheme 157)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 156)and (Scheme 157). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists with either 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 156

Scheme 157

Scheme 158

Scheme 159

1. Two heated Air/Fuel (A/F) sensors are used. Heated A/F sensors are mounted on exhaust manifold above catalytic converter. For testing of A/F sensors, see «AIR/FUEL SENSOR»(ref-63407-S23346034662001020500000). Two heated oxygen sensors are also used. Heated oxygen sensors are mounted on exhaust manifold below catalytic converters. Heated oxygen sensor for cylinders No. 1 and 4 is referred to as bank No. 1 sensor No. 2. Heated oxygen sensor for cylinders No. 2 and 3 is referred to as bank No. 2 sensor No. 2.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor. (Scheme 158)and (Scheme 159). Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 158)and (Scheme 159). 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).
3. If problem exists in either 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 160

1. A heated Air/Fuel (A/F) sensor is mounted on exhaust pipe in front of catalytic converter. For testing of A/F sensor, see «AIR/FUEL SENSOR»(ref-63407-S23346034662001020500000). Another heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 160) 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).
3. If problem exists in either 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.

Camry CNG & Gasoline Models, & Camry Solara

1. Ensure ignition is off. Disconnect electrical connector from intake air temperature sensor. Intake air temperature sensor is located on upper cap on air cleaner housing.
2. Remove intake air temperature sensor. Place probe end of intake air temperature sensor and thermometer in container of water. Attach ohmmeter between electrical terminals on intake air temperature sensor.
3. Heat water and note that resistance is within specification in relation to temperature. (Scheme 141) Replace intake air temperature sensor if resistance is not within specification.

Intake air temperature sensor is incorporated with airflow meter. See AIRFLOW METER .

KNOCK SENSOR

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

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

1. Knock sensor is located on side of cylinder block. (Scheme 161)- (Scheme 168). Manufacturer recommends removing knock sensor from cylinder block before testing. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER 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.

1. Ensure ignition is off. To test Manifold Absolute Pressure (MAP) sensor supply voltage, disconnect electrical connector from MAP sensor. MAP sensor is located in engine compartment, on center of firewall. (Scheme 169)
2. Turn ignition on. Using voltmeter, check MAP sensor supply voltage between terminals E2 and VC on wiring harness side of electrical connector for MAP sensor. (Scheme 170) E2 and VC terminals are the 2 outer terminals on all models. DO NOT use center terminal.
3. MAP sensor supply voltage should be 4.5-5.5 volts. If MAP sensor supply voltage is not within specification, check wiring circuit. See WIRING DIAGRAMS article. If MAP sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on MAP sensor.
4. To test MAP sensor output voltage, turn ignition on. Disconnect vacuum hose from MAP sensor. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article.
5. Note ECM electrical connector terminals. (Scheme 108)and (Scheme 109). Connect voltmeter between ECM terminals E2 and PIM. See «ECM TERMINAL IDENTIFICATION FOR MAP SENSOR»(ref-63407-S18187570702001020500000) table. ECM TERMINAL IDENTIFICATION FOR MAP SENSOR Application & ECM Terminals ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E2 E6 18 (Brown) PIM E6 9 (Black/Yellow) Gasoline Models With Engine Immobilizer E2 E10 18 (Brown) PIM E10 21 (Black/Yellow) Without Engine Immobilizer E2 E10 18 (Brown) PIM E10 9 (Black/Yellow) Camry Solara With Engine Immobilizer E2 E10 18 (Brown) PIM E10 21 (Black/Yellow) Without Engine Immobilizer E2 E10 18 (Brown) PIM E10 9 (Black/Yellow)
6. Measure and record MAP sensor output voltage under ambient atmospheric pressure. Attach vacuum pump to bottom of MAP sensor.
7. Apply vacuum in specified increments and measure MAP sensor output voltage drop at each increment. See «MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS»(ref-63407-S06432062772001020500000) table. Turn ignition off. Replace MAP sensor if MAP sensor output voltage drop is not within specification.

MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS

Scheme 169

Scheme 170

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

Note. Park/Neutral Position (PNP) switch is used only on A/T models.

1. Disconnect electrical connector from PNP switch. PNP switch is mounted on side of transmission/transaxle. Note terminal identification. (Scheme 171)- (Scheme 173).
2. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(ref-63407-S15234583092001020500000) table.
3. If proper continuity does not exist, adjust or replace switch as necessary. For adjustment of PNP switch, see PARK/NEUTRAL POSITION SWITCH under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 171

Scheme 172

Scheme 173

POWER STEERING PRESSURE SENSOR

Note. Power steering pressure sensor may also be referred to as power steering oil pressure sensor.

Power steering pressure sensor is located on side of power steering pump. Testing information is not available from manufacturer. If problem exists with power steering pressure 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.

POWER STEERING PRESSURE SWITCH

Note. Power steering pressure switch may also be referred to as power steering oil pressure switch.

Camry CNG & Gasoline Models, Camry Solara, Celica, Corolla, RAV4 & Tacoma

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

1. 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 114)
2. Start engine and allow engine to idle. Using voltmeter, check voltage between terminals No. 11 (Green/Yellow wire) at ECM electrical connector E7 and No. 17 (Brown wire) at ECM electrical connector E8. This is the PSW and E1 terminals at ECM. Check voltage with steering wheel at stationary position with engine idling, and while turning steering wheel with engine idling. Voltage should be 9-14 volts with steering wheel at stationary position and 0-3 volts while turning the steering wheel. If voltage is within specification, test is complete. If voltage is not within specification, it may be necessary to check wiring harness and electrical connectors between ECM and power steering pressure switch. See WIRING DIAGRAMS article. Power steering pressure switch is located on power steering pump. If wiring harness or electrical connector is defective, repair as necessary. If wiring harness and electrical connectors are okay, it may be necessary to replace power steering pressure switch.

Scheme 174

1. Remove Positive Temperature Coefficient (PTC) heater along with heater core. See appropriate HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
2. To test PTC heater for continuity, using ohmmeter, check that continuity exists between each electrical terminal and ground terminal on PTC heater. (Scheme 174) Replace PTC heater if continuity does not exist between any electrical terminal and ground terminal.
3. To test PTC heater resistance, remove PTC heater from heater core. Place probe end of PTC heater and thermometer in container of water. Attach ohmmeter between electrical terminals on PTC heater.
4. Heat water and note that resistance is within specification in relation to temperature. See «PTC HEATER RESISTANCE»(ref-63407-S41171959832001020500000) table. Replace PTC heater if resistance is not within specification. PTC HEATER RESISTANCE Temperature Ohms 77°F (25°C) 4800-5200 104°F (40°C) 2550-2850 212°F (100°C) 260-340

1. Ensure ignition is off. Disconnect electrical connector from Throttle Position (TP) sensor on throttle body. Note terminal identification on TP sensor. (Scheme 175)- (Scheme 182).
2. On Camry CNG and gasoline models, Camry Solara and Tacoma, disconnect vacuum hose and apply vacuum to throttle opener. (Scheme 175)and (Scheme 182).
3. On all models, using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-63407-S34213645972001020500000) table. Replace components as necessary if resistance is not within specification.

1. On 2000 models, there is only one type of throttle body and Throttle Position (TP) sensor used. On 2001 models, there are 2 types of throttle bodies and TP sensors used depending on type of transaxle used. On models with a standard type manual transaxle, the driver operates the clutch and shifts the transaxle. On models with a sequential manual transaxle, the transaxle is electronically controlled and the clutch is operated and transaxle is shifted hydraulically by moving the shift lever forward or backward. The sequential manual transaxle may be identified by the shift lever pattern which consists of "R", "N", "S" and "+" in place of the conventional type shift lever pattern and no clutch pedal is used.
2. For all 2000 models and 2001 MR2 with standard type manual transaxle, go to next step. For 2001 models with a sequential manual transaxle, see «THROTTLE BODY»(ref-63407-S09643743972001020500000) under IDLE CONTROL SYSTEMS for testing of TP sensor.
3. Ensure ignition is off. Disconnect electrical connector from TP sensor on throttle body. Note terminal identification on TP sensor. (Scheme 180)
4. Using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-63407-S34213645972001020500000) table. Replace components as necessary if resistance is not within specification.

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

THROTTLE POSITION SENSOR RESISTANCE

Scheme 175

Scheme 176

Scheme 177

Scheme 178

Scheme 179

Scheme 180

Scheme 181

Scheme 182

Note. Hydrocarbon absorber catalyst system may also be referred to as HCAC system.

Scheme 183

Scheme 184

1. Ensure ignition is off. To test vacuum sensor supply voltage, disconnect electrical connector from vacuum sensor. Vacuum sensor is located at passenger's side front corner of the engine and contains Black 3-pin connector with Brown, Violet/White and Yellow/Red wires. (Scheme 183)
2. Turn ignition on. Using voltmeter, check vacuum sensor supply voltage between terminals E2 and VC on wiring harness side of electrical connector for vacuum sensor. (Scheme 184) E2 and VC terminals are the 2 outer terminals. DO NOT use center terminal.
3. Vacuum sensor supply voltage should be 4.5-5.5 volts. If vacuum sensor supply voltage is not within specification, check wiring circuit. See WIRING DIAGRAMS article. If vacuum sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on vacuum sensor.
4. To test vacuum sensor output voltage, turn ignition on. Disconnect vacuum hose from vacuum sensor. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article.
5. Note ECM electrical connector terminals. (Scheme 116) Connect voltmeter between terminals No. 14 (Violet/White wire) at ECM electrical connector E9 and No. 18 (Brown wire) at ECM electrical connector E8. This is the HCLS and E1 terminals at ECM.
6. Measure and record vacuum sensor output voltage under ambient atmospheric pressure. Attach vacuum pump to bottom of vacuum sensor. Apply vacuum in specified increments and measure vacuum sensor output voltage drop at each increment. See «VACUUM SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS»(ref-63407-S16529996302001021900000) table. Turn ignition off. Replace vacuum sensor if vacuum sensor output voltage drop is not within specification. VACUUM SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS Applied Vacuum - In. Hg Voltage Drop 3.94.3-.5 7.87.7-.9 11.81 1.1-1.3 15.75 1.5-1.7 19.69 1.9-2.1

VAPOR PRESSURE SENSOR

See VAPOR PRESSURE SENSOR under FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS.

VARIABLE VALVE TIMING SENSOR

Note. Variable Valve Timing (VVT) sensor may also be referred to as camshaft position sensor.

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

For VVT sensor testing, see CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article.

Scheme 185

Scheme 186

Scheme 187

1. Vehicle speed sensor is mounted on transaxle and contains a 3-pin electrical connector. (Scheme 185) Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 186)and (Scheme 187).
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 186)and (Scheme 187).
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 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 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.

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). 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.

Wheel speed sensors on each wheel deliver an input signal to brake Electronic Control Unit (ECU) for the Anti-Lock Brake System (ABS). Brake 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 mounted on transaxle. 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 188

Scheme 189

Scheme 190

1. Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a 3-pin electrical connector. (Scheme 188) Electrical connector contains Blue, Green/Red and Pink wires.
2. Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 187), (Scheme 189) and (Scheme 190).
3. 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 187), (Scheme 189) and (Scheme 190).
4. 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 shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

A/C COMPRESSOR CLUTCH RELAY

Note. A/C compressor clutch relay may also be referred to as A/C compressor relay or magnetic clutch relay.

Scheme 191

1. Remove A/C compressor clutch relay from relay box on firewall at driver's side front corner of engine compartment. (Scheme 198)
2. To test A/C compressor clutch relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on A/C compressor clutch relay. (Scheme 191)
3. To test A/C compressor clutch relay operation, apply battery voltage and ground to A/C compressor clutch relay. Using ohmmeter, check for continuity between specified terminals on A/C compressor clutch relay. (Scheme 191) Replace A/C compressor clutch relay if defective.

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 192

1. Remove A/F heater relay from fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. To test A/F heater relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on A/F heater relay. (Scheme 192)
2. To test A/F heater relay operation, apply battery voltage and ground to A/F heater relay. Using ohmmeter, check for continuity between specified terminals on A/F heater relay. (Scheme 192) Replace A/F heater relay if defective.

1. Remove A/F heater relay from fuse/relay box at driver's side front corner of engine compartment. To test A/F heater relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on A/F heater relay. (Scheme 191)
2. To test A/F heater relay operation, apply battery voltage and ground to A/F heater relay. Using ohmmeter, check for continuity between specified terminals on A/F heater relay. (Scheme 191) Replace A/F heater relay if defective.

CIRCUIT OPENING RELAY

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(ref-63407-S11812691242001020500000) table. (Scheme 193)- (Scheme 201). CIRCUIT OPENING RELAY LOCATION (1) Application Location Camry CNG & Gasoline Models, & Camry Solara In Fuse/Relay Box At driver's side Front Corner Of Engine Compartment, Near Battery Celica In Fuse/Relay Box At driver's side Front Corner Of Engine Compartment, Just In Front Of Strut Tower Corolla Center Relay In Relay Box Behind Driver's Side Kick Panel ECHO In Fuse/Relay Box Behind Driver's Side Of Instrument Panel Highlander In Relay Box Just Above Driver's Side Kick Panel MR2 In Relay Box On Firewall At Driver's Side Front Corner Of Engine Compartment Prius & RAV4 In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment Tacoma Behind Lower Instrument Panel Cover, Next To Driver's Side Of Steering Column (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 116- (Scheme 202).
3. To test circuit opening relay operation, apply battery voltage and ground to circuit opening relay. Using ohmmeter, check for continuity between specified terminals on circuit opening relay. see scheme 116- (Scheme 202). Replace circuit opening relay if defective.

Scheme 193

Scheme 194

Scheme 195

Scheme 196

Scheme 197

Scheme 198

Scheme 199

Scheme 200

Scheme 201

EFI MAIN RELAY

Note. On Corolla, EFI main relay may also be referred to as EFI relay or F-HTR relay. On all other models, EFI main relay may also be referred to as EFI relay.

Scheme 202

1. Ensure ignition is off. Remove EFI main relay. See «EFI MAIN RELAY LOCATION»(ref-63407-S25864735892001020500000) table. EFI MAIN RELAY LOCATION Application Location Camry CNG & Gasoline Models, & Camry Solara In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, Near Battery Celica, Corolla, ECHO & Highlander In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment, Just In Front Of Strut Tower MR2 In Relay Box On Firewall At Driver's Side Front Corner Of Engine Compartment Prius, RAV4 & Tacoma In Fuse/Relay Box At Driver's Side Front Corner Of Engine Compartment
2. To test EFI main relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on EFI main relay. see scheme 116- see scheme 119.
3. To test EFI main relay operation, apply battery voltage and ground to EFI main relay. Using ohmmeter, check for continuity between specified terminals on EFI main relay. see scheme 116- see scheme 119. Replace EFI main relay if defective.

HTR SUB1 RELAY

Note. HTR SUB1 relay may also be referred to as heater sub relay.

Scheme 203

1. Remove HTR SUB1 relay from fuse/relay box located at driver's side front corner of engine compartment, just in front of strut tower. (Scheme 203)
2. Note terminals on HTR SUB1 relay. (Scheme 203) To test HTR SUB1 relay continuity, using ohmmeter, check that continuity exists between terminals No. 1 and 2 on HTR SUB1 relay and that no continuity exists between terminals No. 3 and 5 on HTR SUB1 relay. If continuity and no continuity are as specified, go to next step. If continuity and no continuity are not as specified, replace HTR SUB1 relay.
3. To test HTR SUB1 relay operation, apply battery voltage and ground to terminals No. 1 and 2 on HTR SUB1 relay. Using ohmmeter, check that continuity exists between terminals No. 3 and 5 on HTR SUB1 relay. Replace HTR SUB1 relay if continuity does not exist between terminals No. 3 and 5.

IG2 RELAY

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

IG2 relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower. Testing information is not available from manufacturer. Consult wiring diagram for IG2 relay testing. See WIRING DIAGRAMS article.

1. Remove IG2 relay from relay box on firewall at driver's side front corner of engine compartment. (Scheme 198)
2. To test IG2 relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on IG2 relay. see scheme 121
3. To test IG2 relay operation, apply battery voltage and ground to IG2 relay. Using ohmmeter, check for continuity between specified terminals on IG2 relay. see scheme 121 Replace IG2 relay if defective.

IG2 relay is located in fuse/relay box at driver's side front corner of engine compartment. Testing information is not available from manufacturer. Consult wiring diagram for IG2 relay testing. See WIRING DIAGRAMS article.

1. Remove IG2 relay from relay box located at driver's side front corner of engine compartment. (Scheme 200)
2. To test IG2 relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on IG2 relay. see scheme 121
3. To test IG2 relay operation, apply battery voltage and ground to IG2 relay. Using ohmmeter, check for continuity between specified terminals on IG2 relay. see scheme 121 Replace IG2 relay if defective.

INJ relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery. Testing information is not available from manufacturer. Consult wiring diagram for INJ relay testing. See WIRING DIAGRAMS article.

On 2001 MR2, there are 2 types of manual transaxles used. The sequential manual transaxle may be identified by the shift lever pattern which consists of "R", "N", "S" and "+" in place of the conventional type shift lever pattern and there is no clutch pedal. 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 - 4-CYLINDER article.

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

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

Fuel Pressure Regulator (Camry CNG Models)

Individual component testing information is not available from manufacturer.

Fuel Pressure Regulator Fuel Shutoff Valve (Camry CNG Models)

Note. Fuel pressure regulator fuel shutoff valve may also be referred to as fuel shutoff valve (fuel pressure regulator).

Scheme 204

1. Disconnect electrical connector at fuel pressure regulator fuel shutoff valve. Fuel pressure regulator fuel shutoff valve is located on fuel pressure regulator located in fuel line between fuel tank and fuel rail, just below brake booster. (Scheme 204)
2. Using ohmmeter, check between electrical terminals on electrical connector for fuel pressure regulator fuel shutoff valve. (Scheme 204) Replace fuel pressure regulator fuel shutoff valve along with fuel pressure regulator as an assembly if resistance is not 1.4-1.8 ohms at 68°F (20°C).

Fuel Pump Pressure (Camry Gasoline Models, Camry Solara, Celica, Corolla, ECHO, Highlander, MR2, Prius, RAV4 & Tacoma)

For fuel pump pressure testing, see FUEL PRESSURE under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article.

Fuel Rail Fuel Shutoff Valve (Camry CNG Models)

Note. Fuel rail fuel shutoff valve may also be referred to as delivery pipe fuel shutoff valve or fuel shutoff valve (delivery pipe).

1. Disconnect electrical connector at fuel rail fuel shutoff valve. Fuel rail fuel shutoff valve is located at end of fuel rail at flywheel end of engine and contains a Blue 2-pin electrical connector.
2. Using ohmmeter, check between electrical terminals on electrical connector for fuel rail fuel shutoff valve. Resistance should be 1.8-2.2 ohms at 68°F (20°C). Replace fuel rail fuel shutoff valve if resistance is not within specification.

Scheme 205

Scheme 206

1. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 4.
2. Connect hand-held tester to data link connector No. 3. (Scheme 98) Turn ignition on and then turn hand-held tester on.
3. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturers instructions, operate fuel tank fuel shutoff valve and listen for operating sound at fuel tank fuel shutoff valve. Fuel tank fuel shutoff valve is located on fuel tank valve assembly at end of fuel tank behind rear seat. (Scheme 205) If operating sound is heard, fuel tank fuel shutoff valve and wiring circuit are okay. Remove hand-held tester. If operating sound is not heard, remove hand-held tester and go to step 6.
4. 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 108)
5. Turn ignition on. Connect jumper wire between body ground and terminal No. 3 (Green/Red wire) at ECM electrical connector E4 and listen for operating sound at fuel tank fuel shutoff valve. Fuel tank fuel shutoff valve is located on fuel tank valve assembly at end of fuel tank behind rear seat. (Scheme 205) If operating sound is heard, fuel tank fuel shutoff valve and wiring circuit are okay. If operating sound is not heard, go to next step.
6. Remove rear seat back and rear seat cushion for access to electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor. Electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor is located near driver's side end of fuel tank behind rear seat. (Scheme 206) Disconnect electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor.
7. Using ohmmeter, check resistance between terminals No. 1 and 2 on electrical connector for fuel tank fuel shutoff valve and fuel tank fuel temperature sensor. (Scheme 206) Resistance should be approximately 19 ohms at 68°F (20°C).
8. If resistance is not within specification, replace fuel tank fuel shutoff valve along with fuel tank. If resistance is within specification, but fuel tank fuel shutoff valve fails to operate, check wiring circuit to fuel tank fuel shutoff valve. See WIRING DIAGRAMS article.

Fuel Injectors (Camry CNG Models)

1. To check for fuel injector operation, using stethoscope, listen for clicking sound at each fuel injector, or feel for fuel injector operation at fuel injector with engine cranking or with engine running. If fuel injector operation does not exist, check for loose connection at electrical connector for fuel injector. If electrical connector at fuel injector is okay, go to next step.
2. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, check resistance between electrical terminals on fuel injector. Replace fuel injector if resistance is within specification. See «FUEL INJECTOR RESISTANCE»(ref-63407-S21431385482001020500000) table. If fuel injector resistance is within specification but fuel injector does not operate, it may be necessary to check fuel injector circuit. See «FUEL INJECTOR CIRCUIT»(ref-63407-S31351515632001020500000) under COMPUTERIZED ENGINE CONTROLS.

Fuel Injectors (Camry Gasoline Models & Camry Solara)

1. To check for fuel injector operation, using stethoscope, listen for clicking sound at each fuel injector, or feel for fuel injector operation at fuel injector with engine cranking or with engine running. If fuel injector operation does not exist, check for loose connection at electrical connector for fuel injector. If electrical connector for fuel injector is okay, go to next step.
2. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, check resistance between electrical terminals on fuel injector. Replace fuel injector if resistance is not within specification. See «FUEL INJECTOR RESISTANCE»(ref-63407-S21431385482001020500000) table.
3. If fuel injector operates and fuel injector resistance is within specification, go to next step. If fuel injector resistance is within specification but fuel injector does not operate, check wiring circuit to fuel injector. See WIRING DIAGRAMS article. If problem exists in fuel injector or wiring circuit and misfire exists, 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.
4. To check fuel injector volume, remove fuel injector. See FUEL RAILS & FUEL INJECTORS under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Ensure area around fuel hose on top of fuel filter is clean. Remove union bolts with gaskets, and disconnect fuel hose from top of fuel filter.
5. Install union, delivery hose, gaskets and union bolt from Fuel Injector Measuring Set (SST 09268-41047) on top of fuel filter. (Scheme 207) Tighten union bolt to 21 ft. lbs. (29 N.m).
6. Check that grommet and "O" ring are installed on top of fuel injector. Using clamp and union from fuel injector measuring set, connect fuel injector to delivery hose. (Scheme 207)
7. Place vinyl tube on end of fuel injector to prevent fuel spillage. Place fuel injector into a clean graduated container.
8. Connect Toyota hand-held tester to data link connector No. 3. (Scheme 98)and (Scheme 99). Turn ignition on and then turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump. NOTE: If hand-held tester is not available, fuel pump may also be operated to pressurize fuel system by applying battery voltage to electrical terminals on fuel pump. For operating of fuel pump, see «FUEL PUMP RESISTANCE & OPERATION»(ref-63407-S06092236882001020500000) under FUEL DELIVERY under FUEL SYSTEMS.
9. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 208) Measure fuel injector volume. Test each fuel injector 2-3 times. Replace fuel injector if fuel injector volume is not within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-63407-S00527645322001020500000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-63407-S00527645322001020500000) table.
10. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop in 12 minutes. Replace fuel injector if leakage exceeds one drop in 12 minutes. Disconnect negative battery cable. Remove test equipment.
11. Using NEW gaskets, install fuel hose on top of fuel filter. Tighten union bolt to 21 ft. lbs. (29 N.m). Install negative battery cable. Check for fuel leaks by operating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

Fuel Injectors (Celica, Corolla, ECHO, Highlander, MR2, Prius & RAV4)

1. To check for fuel injector operation, remove No. 2 cylinder head cover on top of engine for access to fuel injectors (if equipped). Using stethoscope, listen for clicking sound at each fuel injector, or feel for fuel injector operation at fuel injector with engine cranking or with engine running. If fuel injector operation does not exist, check for loose connection at electrical connector for fuel injector. If electrical connector for fuel injector is okay, go to next step.
2. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, check resistance between electrical terminals on fuel injector. Replace fuel injector if resistance is not within specification. See «FUEL INJECTOR RESISTANCE»(ref-63407-S21431385482001020500000) table.
3. If fuel injector operates and fuel injector resistance is within specification, go to next step. If fuel injector resistance is within specification but fuel injector does not operate, check wiring circuit to fuel injector. See WIRING DIAGRAMS article. If problem exists in fuel injector or wiring circuit and misfire exists, 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.
4. To check fuel injector volume, remove fuel injector. See FUEL RAILS & FUEL INJECTORS under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
5. On Celica, Corolla, ECHO and MR2, remove fuel pipe clamp from end of fuel pipe at end of fuel rail if not previously done. Perform STEP 1 in illustration. (Scheme 209)- (Scheme 211) and (Scheme 213). Ensure area around fuel pipe and disconnect fitting is clean. Depress both sides of retainer and pull fuel pipe with disconnect fitting from fuel pipe fitting. Perform STEP 2 in illustration. (Scheme 209)- (Scheme 211) and (Scheme 213). Use care when disconnecting fuel pipe, as some residual fuel pressure may still exist in fuel system. Go to step 8.
6. On Highlander and RAV4, remove fuel pipe clamp from end of fuel pipe at end of fuel rail if not previously done. (Scheme 212)and (Scheme 215). Depress both tabs and pull fuel pipe with disconnect fitting from fuel pipe fitting. (Scheme 212)and (Scheme 215). Use care when disconnecting fuel pipe, as some residual fuel pressure may still exist in fuel system. Go to step 8.
7. On Prius, depress both sides of retainer and pull fuel pipe with disconnect fitting from fuel pipe fitting. (Scheme 214) Use care when disconnecting fuel pipe, as some residual fuel pressure may still exist in fuel system. Go to next step.
8. On all models, purchase appropriate fuel pipe from local Toyota parts department. See «FUEL PIPE IDENTIFICATION»(ref-63407-S12265441912001020500000) table. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 216)and (Scheme 217). FUEL PIPE IDENTIFICATION Application Fuel Pipe Part No. Celica 1.8L 1ZZ-FE 23901-22100 1.8L 2ZZ-GE 23271-88600 Corolla 23901-22010 ECHO 23901-21020 Or 23901-22010 Highlander 23901-28070 MR2 23901-22070 Prius 23901-21020 RAV4 23901-22110
9. Install fuel pipe connector on fuel pipe fitting and retainer (if equipped). (Scheme 218) Ensure fuel pipe connector is securely attached on fuel pipe fitting and retainer (if equipped) is fully seated.
10. Connect delivery hose from Fuel Injector Measuring Set (SST 09268-41047) to fuel pipe connector. Check that grommet (if equipped) and "O" ring are installed on top of fuel injector. Using clamp and union from fuel injector measuring set, connect fuel injector to delivery hose. (Scheme 218)
11. Place vinyl tube on end of fuel injector to prevent fuel spillage. Place fuel injector into a clean graduated container.
12. Connect Toyota hand-held tester to data link connector No. 3. (Scheme 100)- (Scheme 106). Turn ignition on and then turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump. NOTE: If hand-held tester is not available, fuel pump may also be operated to pressurize fuel system by applying battery voltage to electrical terminals on fuel pump. For operating of fuel pump, see «FUEL PUMP RESISTANCE & OPERATION»(ref-63407-S06092236882001020500000) under FUEL DELIVERY under FUEL SYSTEMS.
13. Connect Fuel Injector Tester (09842-30080) to fuel injector for 15 seconds. (Scheme 208) Measure fuel injector volume. Test each fuel injector 2-3 times. Replace fuel injector if fuel injector volume is not within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-63407-S00527645322001020500000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-63407-S00527645322001020500000) table.
14. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop in 12 minutes. Replace fuel injector if leakage exceeds one drop in 12 minutes. Disconnect negative battery cable. Remove test equipment.
15. On Celica, Corolla, ECHO, MR2 and Prius, DO NOT reuse old retainer when installing fuel pipe on fuel pipe fitting. Always use a NEW retainer. Apply light coat of engine oil on tip of fuel pipe fitting to allow for ease of disconnect fitting and fuel pipe installation. Using NEW retainer, install fuel pipe on fuel pipe fitting until "click" sound is heard. DO NOT reuse old retainer. Pull on fuel pipe to ensure fuel pipe is properly locked on fuel pipe fitting. Reinstall fuel pipe clamp (if equipped). Go to step 17.
16. On Highlander and RAV4, install fuel pipe on fuel pipe fitting. Pull on fuel pipe to ensure fuel pipe is properly locked on fuel pipe fitting. Reinstall fuel pipe clamp. Go to next step.
17. On all models, install negative battery cable. Check for fuel leaks by operating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

Fuel Injectors (Tacoma)

1. To check for fuel injector operation, using stethoscope, listen for clicking sound at each fuel injector, or feel for fuel injector operation at fuel injector with engine cranking or with engine running. If fuel injector operation does not exist, check for loose connection at electrical connector for fuel injector. If electrical connector for fuel injector is okay, go to next step.
2. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, check resistance between electrical terminals on fuel injector. Replace fuel injector if resistance is not within specification. See «FUEL INJECTOR RESISTANCE»(ref-63407-S21431385482001020500000) table.
3. If fuel injector operates and fuel injector resistance is within specification, go to next step. If fuel injector resistance is within specification but fuel injector does not operate, check wiring circuit to fuel injector. See WIRING DIAGRAMS article. If problem exists in fuel injector or wiring circuit and misfire exists, 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.
4. To check fuel injector volume, remove fuel injector. See FUEL RAILS & FUEL INJECTORS under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Ensure area around fuel hoses on fuel filter is clean. Remove union bolts with gaskets, and disconnect fuel hose from fuel filter. (Scheme 219)
5. Install union, delivery hose, gaskets and union bolt from Fuel Injector Measuring Set (SST 09268-41047) on fuel filter. (Scheme 219) Tighten union bolt to 21 ft. lbs. (29 N.m).
6. Check that "O" ring is installed on top of fuel injector. Using clamp and union from fuel injector measuring set, connect fuel injector to delivery hose. (Scheme 219)
7. Remove fuel pressure regulator from fuel rail. See FUEL PRESSURE REGULATOR under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Using NEW "O" ring, install union on fuel pressure regulator. (Scheme 219) Connect delivery hose to union and fuel return hose on fuel pressure regulator.
8. Place vinyl tube on end of fuel injector to prevent fuel spillage. Place fuel injector into a clean graduated container.
9. Connect Toyota hand-held tester to data link connector No. 3. (Scheme 107) Turn ignition on and then turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate fuel pump. NOTE: If hand-held tester is not available, fuel pump may also be operated to pressurize fuel system by applying battery voltage to electrical terminals on fuel pump. For operating of fuel pump, see «FUEL PUMP RESISTANCE & OPERATION»(ref-63407-S06092236882001020500000) under FUEL DELIVERY under FUEL SYSTEMS.
10. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 208) Measure fuel injector volume. Test each fuel injector 2-3 times. Replace fuel injector if fuel injector volume is not within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-63407-S00527645322001020500000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-63407-S00527645322001020500000) table.
11. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop in 12 minutes. Replace fuel injector if leakage exceeds one drop in 12 minutes. Disconnect negative battery cable. Remove test equipment.
12. Using NEW gaskets, install fuel hose on top of fuel filter. Tighten union bolt to 21 ft. lbs. (29 N.m). Reinstall fuel pressure regulator. Install negative battery cable. Check for fuel leaks by operating the fuel pump by using hand-held tester or connecting battery voltage to fuel pump.

FUEL INJECTOR RESISTANCE

FUEL INJECTOR VOLUME SPECIFICATIONS

Scheme 207

Scheme 208

Scheme 209

Scheme 210

Scheme 211

Scheme 212

Scheme 213

Scheme 214

Scheme 215

Scheme 216

Scheme 217

Scheme 218

Scheme 219

Fuel Cut System (Camry CNG & Gasoline Models, Camry Solara, Celica, Corolla, ECHO, MR2, RAV4 & Tacoma)

1. Connect Toyota hand-held tester or scan tool to data link connector No. 3. (Scheme 98)- (Scheme 107). Hand-held tester or scan tool is used to read engine RPM. Start engine and warm engine to normal operating temperature.
2. Ensure A/C is off. Gradually increase engine speed to specified RPM. See «FUEL CUT SYSTEM TESTING SPEED»(ref-63407-S14895456082001020500000) table. FUEL CUT SYSTEM TESTING SPEED Application Engine RPM Camry CNG & Gasoline Models, & Camry Solara 2500 Celica, Corolla, ECHO, MR2, RAV4 & Tacoma 3500
3. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily and then resumes operating (fuel return RPM).
4. Ensure fuel return RPM is within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(ref-63407-S24019051042001020500000) table. Shut engine off. Remove hand-held tester or scan tool.

FUEL CUT SYSTEM SPECIFICATIONS (1)

Fuel Cut System (Highlander)

1. Connect Toyota hand-held tester or scan tool to data link connector No. 3. (Scheme 103) Hand-held tester or scan tool is used to read engine RPM. Start engine and 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.

Fuel Cut System (Prius)

Scheme 220

1. It is necessary to put transit in inspection mode so engine will run continuously when checking fuel cut system. To put transit in inspection mode, perform the following steps within 60 seconds: Ensure ignition is off and then turn ignition on. Ensure transaxle is in Park and then fully depress accelerator pedal 2 times. Place transaxle in Neutral and then fully depress accelerator pedal 2 times. Place transaxle back in Park and then fully depress accelerator pedal 2 times.
2. Check that master warning light on instrument cluster at center of instrument panel is flashing to indicate inspection mode operation. (Scheme 220) Master warning light may also be referred to as hybrid system error warning light. Turn ignition switch to START position to start engine. Engine will now start and run continuously.
3. Connect Toyota hand-held tester or scan tool to data link connector No. 3. (Scheme 105) Hand-held tester or scan tool is used to read engine RPM. Warm engine to normal operating temperature.
4. Ensure A/C is off. Gradually increase engine speed to 2250 RPM. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily and then resumes operating. Ensure when throttle lever is released, fuel injector stops operating momentarily and then resumes operating at 1400 RPM which is the fuel return RPM. Shut engine off. Remove hand-held tester or scan tool.

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transaxle in Neutral. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 221)and (Scheme 222). Data link connector is located at passenger's side of engine compartment, near strut tower.
3. Start engine and note engine speed. Engine speed should increase to 900-1300 RPM for 5 seconds and then return to idle speed. If engine speed is as specified, turn ignition off and remove jumper wire. If engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step.
4. To test Idle Air Control (IAC) valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
5. Check that valve on inside of IAC valve is half open. (Scheme 223) Reinstall electrical connector on IAC valve.
6. Turn ignition on. Check that valve on inside of IAC valve moves within.5 seconds to fully closed, fully open and then to half open. Turn ignition off.
7. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. 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.

Scheme 221

Scheme 222

Scheme 223

Scheme 224

Scheme 225

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transaxle in Neutral. Ensure A/C is off. Install Jumper Wire (SST 09843-18020) between terminals No. 4 (CG) and No. 13 (TC) on data link connector No. 3. (Scheme 224) Data link connector No. 3 is located behind driver's side of instrument panel. (Scheme 100)and (Scheme 102).
3. Start engine and note engine speed. Engine speed should increase to 900-1300 RPM for 5 seconds and then return to idle speed. If engine speed is as specified, turn ignition off and remove jumper wire. If engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step.
4. To test Idle Air Control (IAC) valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Check that valve on inside of IAC valve is half open. (Scheme 225) Reinstall electrical connector on IAC valve.
5. Disconnect electrical connector from Engine Coolant Temperature (ECT) sensor. On Celica, ECT sensor is located on flywheel end of cylinder head and contains Gray 2-pin electrical connector with Green and Brown wires. On ECHO, ECT sensor is located on flywheel end of cylinder head and contains Gray 2-pin electrical connector with Red/Blue and Brown wires.
6. On all models, turn ignition on. Check that valve on inside of IAC valve moves. Repeatedly disconnect and reconnect electrical connector for IAC valve several times while checking that valve on inside of IAC valve opens and closes. (Scheme 225)
7. Turn ignition off. Reinstall electrical connector on ECT sensor. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. If IAC valve does not operate, check wiring circuit between ECM and IAC valve. On Celica, ECM is located in engine compartment, below cover, just in front of battery, next to driver's side strut tower. On ECHO, ECM is located behind glove box. On all models, for illustration of ECM location, see THEORY & OPERATION article. See WIRING DIAGRAMS article. If wiring circuit and ECM are okay, replace IAC valve.

Scheme 226

Scheme 227

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transaxle in Neutral. Ensure A/C is off. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 226) Data link connector No. 1 is located at driver's side of engine compartment, near strut tower.
3. Start engine and note engine speed. Engine speed should increase to 900-1300 RPM for 5 seconds and then return to idle speed. If engine speed is as specified, turn ignition off and remove jumper wire. If engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step.
4. To test Idle Air Control (IAC) valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Check that valve on inside of IAC valve is half open. (Scheme 227) Reinstall electrical connector on IAC valve.
5. Disconnect electrical connector from Engine Coolant Temperature (ECT) sensor. ECT sensor is located on flywheel end of cylinder head and contains Dark Gray 2-pin electrical connector with White and Brown wires.
6. Turn ignition on. Check that valve on inside of IAC valve moves. Repeatedly disconnect and reconnect electrical connector for IAC valve several times while checking that valve on inside of IAC valve opens and closes. (Scheme 227)
7. Turn ignition off. Reinstall electrical connector on ECT sensor. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. If IAC valve does not operate, check wiring circuit between ECM and IAC valve. ECM is located behind stereo on instrument panel, just in front of center console. For illustration of ECM location, see THEORY & OPERATION article. It may be necessary to remove bolts from ECM so electrical connectors can be accessed on ECM. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. See WIRING DIAGRAMS article. If wiring circuit and ECM are okay, replace IAC valve.

Scheme 228

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 valve 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 228) Turn ignition off. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. Clear DTCs from ECM after checking IAC valve operation.
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.

Scheme 229

1. On all 2000 models, Idle Air Control (IAC) valve is used on all models. On 2001 models, IAC valve is used only on models with standard type manual transaxle. On models with a standard type manual transaxle, the driver operates the clutch and shifts the transaxle. On models with a sequential manual transaxle, the transaxle is electronically controlled and the clutch is operated and transaxle is shifted hydraulically by moving the shift lever forward or backward. The sequential manual transaxle may be identified by the shift lever pattern which consists of "R", "N", "S" and "+" in place of the conventional type shift lever pattern and no clutch pedal is used. IAC valve is not used on this model.
2. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
3. Turn ignition off. Apply parking brake and place transaxle in Neutral. Ensure A/C is off. Install Jumper Wire (SST 09843-18020) between terminals No. 4 (CG) and No. 13 (TC) on data link connector No. 3. (Scheme 224) Data link connector No. 3 is located behind driver's side of instrument panel. (Scheme 104)
4. Start engine and note engine speed. Engine speed should increase to 1000-1500 RPM for 5 seconds and then return to idle speed. If engine speed is as specified, turn ignition off and remove jumper wire. If engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step.
5. To test IAC operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Check that valve on inside of IAC valve is half open. (Scheme 229) Reinstall electrical connector on IAC valve.
6. Turn ignition on. Check that valve on inside of IAC valve moves within 0.5 seconds to fully closed, fully open and then to half open. Turn ignition off.
7. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. If IAC valve does not operate, check wiring circuit between ECM and IAC valve. ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. For illustration of ECM location, see THEORY & OPERATION article. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article for removal of components for access to ECM. See WIRING DIAGRAMS article. If wiring circuit and ECM are okay, replace IAC valve.

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transaxle in Neutral. Ensure A/C is off. Install Jumper Wire (SST 09843-18020) between terminals No. 4 (CG) and No. 13 (TC) on data link connector No. 3. (Scheme 224) Data link connector No. 3 is located behind driver's side of instrument panel. (Scheme 106)
3. Start engine and note engine speed. Engine speed should increase to 900-1500 RPM for 5 seconds and then return to idle speed. If engine speed is as specified, turn ignition off and remove jumper wire. If engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step.
4. To test Idle Air Control (IAC) valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Check that valve on inside of IAC valve is half open. (Scheme 228) Reinstall electrical connector on IAC valve.
5. 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. Turn ignition off.
6. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. If IAC valve does not operate, check wiring circuit between ECM and IAC valve. ECM is located behind passenger's side kick panel, just below instrument panel. For illustration of ECM location, see THEORY & OPERATION article. See WIRING DIAGRAMS article. If wiring circuit and ECM are okay, replace IAC valve.

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transmission in Neutral. Install jumper wire between terminals No. 4 (CG) and 13 (TC) on data link connector No. 3. (Scheme 224) Data link connector No. 3 is located behind driver's side of instrument panel. (Scheme 107)
3. Start engine and note engine speed. Engine speed should increase to 1000-1500 RPM for 5 seconds and then return to idle speed. If engine speed is as specified, turn ignition off and remove jumper wire. If engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step.
4. To test Idle Air Control (IAC) valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Check that valve on inside of IAC valve is half open. (Scheme 230) Reinstall electrical connector on IAC valve.
5. Disconnect electrical connector from Engine Coolant Temperature (ECT) sensor. ECT sensor is located on coolant housing at rear of cylinder head and contains Dark Gray 2-pin electrical connector with Green/Red and Light Green wires.
6. Turn ignition on. Check that valve on inside of IAC valve moves. Repeatedly disconnect and reconnect electrical connector for IAC valve several times while checking that valve on inside of IAC valve opens and closes. (Scheme 230)
7. Turn ignition off. Reinstall electrical connector on ECT sensor. If IAC valve operates as specified, wiring circuit, Engine Control Module (ECM) and IAC valve are okay. 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.

Scheme 230

Camry CNG & Gasoline Models, Camry Solara & Tacoma

1. Check that throttle linkage moves freely at throttle body. To check vacuum supply at throttle body, start engine and allow engine to idle. Note vacuum port location on throttle body. (Scheme 231)and (Scheme 232).
2. Check that vacuum and no vacuum exist at specified vacuum ports on throttle body with engine idling and with engine at more than idle. See «THROTTLE BODY VACUUM SUPPLY»(ref-63407-S36523374342001020500000) table. Repair or replace components if vacuum supply is not as designated.

THROTTLE BODY VACUUM SUPPLY

Scheme 231

Scheme 232

Celica, Corolla, ECHO, Highlander, 2000 MR2, 2001 MR2 With Standard Type Manual Transaxle & RAV4

Check that throttle linkage moves freely at throttle body. Procedure for checking vacuum supply at throttle body is not available from manufacturer.

Scheme 233

Scheme 234

Scheme 235

Scheme 236

Scheme 237

1. There are 2 types of manual transaxles used. The sequential manual transaxle may be identified by the shift lever pattern which consists of "R", "N", "S" and "+" in place of the conventional type shift lever pattern and there is no clutch pedal. On this models, 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).
2. Ensure throttle cable and throttle lever on throttle body move smoothly. Note location of throttle control motor on throttle body. (Scheme 233)
3. 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 note that no grinding noise is heard at throttle control motor and throttle body. Throttle lever will also rotate accelerator pedal position sensor.
4. 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 ECM may be defective. ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. For illustration of ECM location, see THEORY & OPERATION article. To remove components for access to ECM, see ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Go to step 13 for testing of throttle control motor. For wiring of throttle control motor, see WIRING DIAGRAMS article.
5. To test operation of accelerator pedal position sensor, Toyota hand-held tester may be used or voltmeter may be used. If using hand-held tester, go to next step. If using voltmeter, go to step 9.
6. Connect hand-held tester to data link connector No. 3. (Scheme 104) 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.
7. 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.
8. If throttle valve opening is at least 60 percent, go to step 11. 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 17 for testing of accelerator pedal position sensor. For wiring of accelerator pedal position sensor, see WIRING DIAGRAMS article.
9. Access ECM. ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. For illustration of ECM location, see THEORY & OPERATION article. To remove components for access to ECM, see ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
10. Ensure ignition is on. Using voltmeter, check voltage between ECM terminals VPA (Blue wire) and E2 (Brown wire) with accelerator pedal released and with accelerator pedal fully depressed. (Scheme 234) Voltage should.3-.9 volt with accelerator pedal released and 3.2-4.7 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 17 for testing of accelerator pedal position sensor. For wiring of accelerator pedal position sensor, see WIRING DIAGRAMS article.
11. 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 Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.
12. To test operation of air assist system, allow engine to warm to normal operating temperature. Apply parking brake. Place transaxle in Neutral. Ensure A/C is off. Note engine idle speed. Engine idle speed should be 700-800 RPM. If all previous steps have been performed, drive vehicle to verify proper operation of throttle body.
13. To test throttle control motor, disconnect electrical connector at throttle control motor. (Scheme 233) It may be necessary to remove throttle body for access to electrical connector at throttle control motor. If necessary to remove throttle body, see THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
14. Note terminal identification on throttle control motor. (Scheme 235) Using ohmmeter, check resistance between specified terminals on throttle control motor. See «THROTTLE CONTROL MOTOR RESISTANCE»(ref-63407-S12203805332001022600000) table. If resistance is within specification, reinstall electrical connector. Go to next step. If resistance is not within specification, replace throttle body with throttle control motor as an assembly. THROTTLE CONTROL MOTOR RESISTANCE Terminal No. Ohms @ 68°F (20°C) 1 & 2.3-100.0 3 & 4 4.2-5.2
15. To test TP sensor, it may be necessary to remove throttle body for access to electrical connector at TP sensor. If necessary to remove throttle body, see THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
16. Disconnect electrical connector at TP sensor. (Scheme 233) Using ohmmeter, check resistance between terminals VC and E2 on TP sensor. (Scheme 236) Replace TP sensor if resistance is not 1200-3200 ohms at 68°F (20°C). See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
17. To test accelerator pedal position sensor, it may be necessary to remove throttle body for access to electrical connector at TP sensor. If necessary to remove throttle body, see THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
18. Disconnect electrical connector at accelerator pedal position sensor. (Scheme 233) Using ohmmeter, check resistance between terminals VC and E2 on accelerator pedal position sensor. (Scheme 237) Replace accelerator pedal position sensor if resistance is not 1200-3200 ohms at 68°F (20°C). See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.

Scheme 238

Scheme 239

Scheme 240

1. 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, Hybrid Vehicle Control Electronic Control Unit (HV ECU) and Engine Control Module (ECM).
2. To inspect ETCS operation, ensure ignition is off. Disconnect electrical connector at throttle control motor on throttle body. (Scheme 238)
3. To test TP sensor operation, connect Toyota hand-held tester to data link connector No. 3. (Scheme 105) Turn ignition on. Hand-held tester is used to read throttle valve opening which is displayed as a percentage.
4. Rotate throttle linkage to full throttle while reading throttle valve opening on hand-held tester which is accessed by THROTTLE POS under CURRENT DATA. Throttle valve opening should be at least 60 percent. If throttle valve opening is at least 60 percent, go to next step. If throttle valve opening is not at least 60 percent, problem may exist in TP sensor, wiring circuit or ECM. Go to step 10 for testing of TP sensor. If necessary to check wiring between ECM and TP sensor, see WIRING DIAGRAMS article. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article.
5. Turn ignition off. Reinstall electrical connector at throttle control motor. It is necessary to put transit in inspection mode so engine will run continuously. To put transit in inspection mode, perform the following steps within 60 seconds: Ensure ignition is off and then turn ignition on. Ensure transaxle is in Park and then fully depress accelerator pedal 2 times. Place transaxle in Neutral and then fully depress accelerator pedal 2 times. Place transaxle back in Park and then fully depress accelerator pedal 2 times.
6. Check that master warning light on instrument cluster at center of instrument panel is flashing to indicate inspection mode operation. (Scheme 220) Master warning light may also be referred to as hybrid system error warning light. Turn ignition switch to START position to start engine. Engine will now start and run continuously.
7. Warm engine to normal operating temperature. To check charging rate of High Voltage (HV) battery, apply brake and place shift lever in Drive and check that engine shuts off. If engine shuts off, go to next step. If engine does not shut off, charging rate of HV battery may be low. Place shift lever in Park and allow engine to run for a while to charge the HV battery. After engine has ran for a while, place shift lever in Drive and check that engine shuts off. If engine now shuts off, go to next step. If engine does not shut off, it may be necessary to place shift lever in Park and allow engine to run for a while to charge the HV battery.
8. With engine idling, turn A/C switch to ON and OFF positions while noting engine idle speed. Idle speed should be 950-1050 RPM with A/C switch in OFF position and 1150-1250 RPM with A/C switch in ON position. If idle speed is not as specified, go to next step. If idle speed is as specified, shut engine off. Remove hand-held tester.
9. To test throttle control motor, disconnect electrical connector for throttle control motor. (Scheme 238) Using ohmmeter, check resistance between terminals No. 1 and 2 on electrical connector for throttle control motor. (Scheme 239) Resistance should be.3-100.0 ohms at 68°F (20°C). If resistance is within specification, reinstall electrical connector. Go to next step. If resistance is not within specification, replace throttle body with throttle control motor as an assembly.
10. To test TP sensor, disconnect electrical connector at TP sensor. (Scheme 238) Using ohmmeter, check resistance between terminals VC and E2 on TP sensor. (Scheme 240) Resistance should be 1200-3200 ohms at 68°F (20°C). If resistance is within specification, reinstall electrical connector. Go to next step. If resistance is not within specification, replace TP sensor. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
11. It may be necessary to check accelerator pedal position sensor. See «ACCELERATOR PEDAL POSITION SENSOR»(ref-63407-S36467410622000120800000) under ENGINE SENSORS & SWITCHES. If TP sensor, throttle control motor and accelerator pedal position sensor are okay, but ETCS does not operate properly, it may be necessary to check wiring between ECM and TP sensor, ECM and throttle control motor, ECM and HV ECU. See WIRING DIAGRAMS article. ECM is located behind glove box. HV ECU is located below carpet on floor panel, just below passenger's side of instrument panel. For illustration of ECM location, see THEORY & OPERATION article.

IGNITION SYSTEMS

Note. For basic ignition checks, see IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article.

See KNOCK SENSOR under ENGINE SENSORS & SWITCHES.

EMISSION SYSTEMS & SUB-SYSTEMS

Note. For emission system component location, refer to illustrations. (Scheme 241)- (Scheme 250). On Highlander, illustration was not available from manufacturer.

Scheme 241

Scheme 242

Scheme 243

Scheme 244

Scheme 245

Scheme 246

Scheme 247

Scheme 248

Scheme 249

Scheme 250

EXHAUST GAS RECIRCULATION SYSTEM

Note. When performing EGR system check, it may be necessary to monitor engine RPM by using Toyota hand-held tester or scan tool. Hand-held tester or scan tool may be connected to data link connector No. 3 for monitoring engine RPM. (Scheme 98), (Scheme 99) and (Scheme 107).

Scheme 251

1. Remove cap and filter from top of EGR vacuum modulator. (Scheme 241)and (Scheme 242). Ensure filter is clean and in good condition. Clean filter with compressed air (if necessary).
2. Reinstall filter and cap. Ensure filter is installed in EGR vacuum modulator with coarse side facing upward, away from EGR vacuum modulator. Using 3-way connector, install vacuum gauge in vacuum hose on top of EGR valve. This is vacuum hose that goes from top of EGR valve to EGR Vacuum Switching Valve (VSV). Start engine. Ensure engine idles smoothly to ensure proper seating of EGR valve.
3. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 221)and (Scheme 222). Data link connector No. 1 is located at passenger's side of engine compartment, near strut tower.
4. To test operation of EGR VSV with engine cold, ensure engine coolant temperature is less than 131°F (55°C). Increase and maintain engine speed at 2500 RPM. Ensure no vacuum reading is obtained on vacuum gauge with engine speed at 2500 RPM.
5. To test operation of EGR VSV with engine warm, operate engine until engine coolant temperature is greater than 140°F (60°C). Operate engine at 2500 RPM again. Ensure a low vacuum reading is obtained on vacuum gauge with engine speed at 2500 RPM.
6. Disconnect vacuum hose from port "R" on EGR vacuum modulator. (Scheme 251) Using additional hose, connect port "R" on EGR vacuum modulator directly to intake manifold. Operate engine at 2500 RPM again. High vacuum reading should be obtained at 2500 RPM. Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
7. Shut engine off. Remove vacuum hose and vacuum gauge. Reconnect original vacuum hoses. Remove jumper wire from data link connector No. 1.
8. To test EGR valve operation, remove and plug vacuum hose located on top of EGR valve. Start engine. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall if EGR valve is operating properly. If EGR system does not operate as described, each individual component should be tested. Shut engine off.

System Check (Tacoma 2.7L 3RZ-FE)

1. Remove cap and filter from top of EGR vacuum modulator. (Scheme 250) Ensure filter is clean and in good condition. Clean filter with compressed air (if necessary).
2. Reinstall filter and cap. Ensure filter is installed in EGR vacuum modulator with coarse side facing upward, away from EGR vacuum modulator. Using 3-way connector, install vacuum gauge in vacuum hose between top of EGR valve and EGR vacuum modulator. Perform STEP 1 in illustration. (Scheme 252) Start engine. Ensure engine idles smoothly to ensure proper seating of EGR valve.
3. To test operation of EGR Vacuum Switching Valve (VSV) with engine cold, ensure engine coolant temperature is less than 122°F (50°C). Increase and maintain engine speed at 3500 RPM. Ensure no vacuum reading is obtained on vacuum gauge with engine speed at 3500 RPM and EGR pipe is not hot.
4. Test operation of EGR VSV and EGR vacuum modulator. Shut engine off. This test procedure may be performed by using Toyota hand-held tester to operate EGR VSV, or by connecting vacuum hose from port "Q" on EGR vacuum modulator to EGR valve. If using hand-held tester, go to next step. If hand-held tester is not available, go to step 6.
5. Connect hand-held tester to data link connector No. 3. (Scheme 107) Select ACTIVE TEST MODE on hand-held tester so EGR VSV is closed. Start engine. Operate engine at 3500 RPM. Ensure a low vacuum reading is obtained on vacuum gauge with engine speed at 3500 RPM. Shut engine off. Remove hand-held tester. Go to step 8.
6. Remove 3-way connector and small vacuum hose between port "Q" (single port) on EGR vacuum modulator and EGR valve. Perform STEP 2 in illustration. (Scheme 252) This 3-way connector and small vacuum hose goes from EGR valve and EGR vacuum modulator to EGR VSV. Install plug in vacuum hose to EGR VSV.
7. Connect vacuum hose from port "Q" on EGR vacuum modulator directly to EGR valve. (Scheme 251) This will by-pass EGR VSV. Start engine. Operate engine at 3500 RPM. Ensure a low vacuum reading is obtained on vacuum gauge with engine speed at 3500 RPM. Shut engine off. Reconnect vacuum hoses. Go to next step.
8. To check EGR valve operation, remove and plug hose at EGR valve. Start engine. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested.

Scheme 252

EGR Gas Temperature Sensor (Tacoma 2.7L 3RZ-FE)

See EGR GAS TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES.

EGR Vacuum Modulator (Camry CNG & Gasoline Models, Camry Solara, & Tacoma 2.7L 3RZ-FE)

1. When testing EGR vacuum modulator, it may be necessary to monitor engine RPM by using Toyota hand-held tester or scan tool. Toyota hand-held tester or scan tool may be connected to data link connector No. 3 for monitoring engine RPM. (Scheme 98), (Scheme 99) and (Scheme 107).
2. Mark vacuum hose locations and disconnect vacuum hoses from EGR vacuum modulator. (Scheme 241), (Scheme 242) and (Scheme 250).
3. Block ports "P" and "R" on EGR vacuum modulator. (Scheme 251) Ports "P" and "R" are the double ports on side of EGR vacuum modulator. Port "Q" is single port on side of EGR vacuum modulator.
4. Apply air pressure to port "Q". (Scheme 251) Air should flow freely through air filter side of EGR vacuum modulator.
5. Start engine and operate engine at specified RPM. See «EGR VACUUM MODULATOR TESTING SPECIFICATIONS»(ref-63407-S41842307422001020500000) table. Repeat test procedures in steps 3) and 4). Strong resistance of airflow should be felt with engine at specified RPM. Replace EGR vacuum modulator if strong resistance is not felt. Reconnect vacuum hoses to proper locations.

EGR VACUUM MODULATOR TESTING SPECIFICATIONS

Scheme 253

1. Disconnect electrical connector from EGR Vacuum Switching Valve (VSV). (Scheme 241)and (Scheme 242). EGR VSV is located on cylinder head, below intake manifold and contains Blue 2-pin electrical connector with Pink/Black and Black/Yellow wires.
2. Using ohmmeter, check that continuity exists between electrical terminals on EGR VSV and that resistance is 33-39 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists or resistance is not within specification.
3. 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. (Scheme 253) Apply battery voltage and ground to electrical terminals on EGR VSV.
5. Apply air pressure to port "E". Ensure air flows from filter and not from port "G". Perform STEP 2 in illustration. (Scheme 253) Replace EGR VSV if defective.

Scheme 254

1. Disconnect electrical connector from EGR Vacuum Switching Valve (VSV). (Scheme 250) EGR VSV is located on bracket, near throttle body and contains Green 2-pin electrical connector with White/Red and Red/Black wires.
2. Using ohmmeter, check that continuity exists between electrical terminals on EGR VSV and that resistance is 33-39 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists or resistance is not within specification.
3. Ensure no continuity exists between each electrical terminal and body of EGR VSV body. 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 does not flow from port "F". Perform STEP 1 in illustration. (Scheme 254) Apply battery voltage and ground to electrical terminals on EGR VSV.
5. Apply air pressure to port "E". Ensure air flows from port "F". Perform STEP 2 in illustration. (Scheme 254) Replace EGR VSV if defective.

EGR Valve (Camry CNG & Gasoline Models, Camry Solara & Tacoma 2.7L 3RZ-FE)

1. Remove EGR valve. See EGR VALVE under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER 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.

HYDROCARBON ABSORBER CATALYST SYSTEM

Note. Hydrocarbon absorber catalyst system may also be referred to as HCAC system.

Scheme 255

Scheme 256

Scheme 257

1. Hydrocarbon absorber may also be referred to as HC absorber. Start engine and warm engine to normal operating temperature. Shut engine off. If using Toyota hand-held tester, go to next step. If Toyota hand-held tester is not available, go to step 3.
2. Connect hand-held tester to data link connector No. 3. (Scheme 105) Start engine. Turn hand-held tester on. Select proper mode on hand-held tester to operate HCAC Vacuum Switching Valve (VSV). Go to step 4.
3. Disconnect electrical connector at HCAC Vacuum Switching Valve (VSV). (Scheme 255) HCAC VSV is located on bracket bolted to timing chain end of engine and uses a Brown 2-pin electrical connector with Black and Black/White wires. Apply battery voltage and ground to electrical terminals on HCAC VSV to operate HCAC VSV. (Scheme 256) Start engine. Go to next step.
4. With engine idling and HCAC VSV operating, check that rod on actuator is pulled inward and that by-pass valve moves. Actuator and by-pass valve are located at front of three-way catalytic converter on exhaust pipe. (Scheme 257) If rod on actuator is not pulled inward and by-pass valve does not move, shut engine off. Go to next step. If rod on actuator is pulled inward and by-pass valve moves, HCAC system is operating properly. Shut engine off. Reinstall electrical connector at HCAC VSV (if removed) and disconnect hand-held tester (if used).
5. Check vacuum hose and line to HCAC VSV. If vacuum hose and line are okay, check operation of actuator for HCAC system and HCAC VSV. See «ACTUATOR FOR HCAC SYSTEM & BY-PASS VALVE»(ref-63407-S07910841462001030500000) and «HCAC VACUUM SWITCHING VALVE»(ref-63407-S23561817232001030500000). If vacuum hose or line are defective, replace components as necessary and recheck system operation.

Actuator For HCAC System & By-Pass Valve (Prius)

1. Remove front exhaust pipe. Remove actuator from front exhaust pipe. (Scheme 257) To check the actuator, using vacuum pump, apply 9.83 in. Hg of vacuum to actuator while checking to see if rod on actuator is pulled inward. If rod is pulled inward, actuator is operating properly. If rod is not pulled inward, replace actuator.
2. To check by-pass valve, ensure by-pass valve can be rotated in front exhaust pipe. If by-pass valve will not rotate, replace front exhaust pipe. Reinstall actuator and front exhaust pipe.

HCAC Vacuum Switching Valve (Prius)

Scheme 258

1. Remove HCAC Vacuum Switching Valve (VSV). (Scheme 255) HCAC VSV is located on bracket bolted to timing chain end of engine and uses a Brown 2-pin electrical connector with Black and Black/White wires.
2. Using ohmmeter, check that continuity exists between electrical terminals on HCAC VSV and that resistance is 33-39 ohms at 68°F (20°C). Replace HCAC VSV if no continuity exists or resistance is not within specification.
3. Ensure no continuity exists between each electrical terminal and body of HCAC VSV body. Replace HCAC VSV if continuity exists between electrical terminal and body of HCAC VSV.
4. To test HCAC VSV operation, apply air pressure to port "E". Ensure air flows from air filter and not from port "F". Perform STEP 1 in illustration. (Scheme 258) Apply battery voltage and ground to electrical terminals on HCAC VSV.
5. Apply air pressure to port "E". Ensure air flows from port "F" and not from air filter. Perform STEP 2 in illustration. (Scheme 258) Replace HCAC VSV if defective.

FUEL EVAPORATIVE SYSTEM

Note. Fuel evaporative system is not used on Camry CNG models. Fuel evaporative system is referred to as fuel EVAP system and may contain different components depending on application. (Scheme 242)- (Scheme 250). When testing fuel EVAP system components, use proper illustration to determine component location.

Note. On Camry gasoline models, Camry Solara, Celica, Corolla, ECHO, Highlander, MR2, Prius and RAV4, 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. (Scheme 242)- (Scheme 248). 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.

Note. Manufacturer provides testing information for testing airtightness of fuel tank and components along with testing of charcoal canister and fuel EVAP system.

Scheme 259

Scheme 260

Scheme 261

Scheme 262

Scheme 263

Scheme 264

Scheme 265

1. Inspect all fuel EVAP system lines and connections for sharp bends or damage. Fuel inlet pipe may also be referred to as fuel filler pipe. Inspect fuel inlet pipe for cracks, damage or fuel leakage. Inspect fuel tank cap for cracks or deformed gasket. Replace components if defective or damaged.
2. Start engine and warm engine to normal operating temperature. Shut engine off. Connect vacuum gauge from EVAP System Test Kit (00002-6872A-01) to EVAP service port. EVAP service port is located in engine compartment, in purge vacuum hose for EVAP system. (Scheme 242)- (Scheme 244), (Scheme 246) and (Scheme 248).
3. Operate EVAP Vacuum Switching Valve (VSV). If Toyota hand-held tester is available to operate EVAP VSV, go to next step. If Toyota hand-held tester is not available to operate EVAP VSV, go to step 5.
4. Connect hand-held tester to data link connector No. 3. (Scheme 98)- (Scheme 101), (Scheme 104) and (Scheme 106). Start engine. Turn hand-held tester on. Select ACTIVE TEST MODE on hand-held tester. Using hand-held tester manufacturer's instructions, activate EVAP VSV. Go to step 6.
5. Disconnect electrical connector at EVAP VSV. See «EVAP VSV LOCATION»(ref-63407-S32664494182001020500000) table. (Scheme 242)- (Scheme 244), (Scheme 246) and (Scheme 248). Using jumper wires, connect battery voltage and ground to electrical terminals on EVAP VSV to operate EVAP VSV. Start engine. Go to next step. EVAP VSV LOCATION Application Location Camry Gasoline Models & Camry Solara On Bracket Near Air Cleaner Housing & Driver's Side Strut Tower, & Contains Black 2-Pin Electrical Connector With Violet/White & Black/Yellow Wires Celica On Bracket At Rear Of Air Cleaner Housing & Contains Black 2-Pin Electrical Connector With Green/Orange & Black/White Wires Corolla On Bracket At Rear Of Air Cleaner Housing & Contains Black 2-Pin Electrical Connector With Blue/Black & Black Wires MR2 On Air Intake Hose, Near Air Cleaner Assembly & Contains Blue 2-Pin Electrical Connector With Black/Red & White Wires RAV4 On Air Intake Hose, Near Air Cleaner Assembly & Contains Black 2-Pin Electrical Connector With Black/Red & Pink Wires
6. Check vacuum reading on vacuum gauge with engine idling. Vacuum reading should be within specification for over 5 seconds. See «VACUUM SPECIFICATIONS»(ref-63407-S05566439992000122200000) table. If vacuum reading is within specification, go to next step. If vacuum reading is not within specification, check for loose or restricted vacuum hose to EVAP service port, or for malfunctioning EVAP VSV. To check EVAP VSV operation, see «EVAP VACUUM SWITCHING VALVE»(ref-63407-S20399202732001020500000). VACUUM SPECIFICATIONS Application In. Hg (In. H20) Camry Gasoline Models, Camry Solara, Celica & Corolla.368-19.713 (5.00-268.00) MR2 & RAV4.368-3.678 (5.00-50.00)
7. Shut engine off. If using hand-held tester to operate EVAP VSV, stop operation of EVAP VSV. Remove hand-held tester. Go to next step. If connecting battery voltage to EVAP VSV to operate EVAP VSV, disconnect jumper wires and reconnect electrical connector on EVAP VSV. Go to next step.
8. Disconnect vacuum gauge from EVAP service port. Connect pressure gauge to EVAP service port. Install hose crimper on air drain hose near charcoal canister. Perform STEP 1 in illustration. (Scheme 259)- (Scheme 262). Charcoal canister is located near fuel tank. (Scheme 242)- (Scheme 244), (Scheme 246) and (Scheme 248).
9. Apply 13.5-15.5 in. H2O of pressure to EVAP service port. After 2 minutes of applying pressure, pressure should be 7.7-8.8 in. H2O. If pressure is within specification, go to next step. If pressure cannot be maintained, remove hose crimper. Check for disconnected vacuum hose between EVAP VSV, charcoal canister and fuel tank. If vacuum hose is properly installed on EVAP VSV, charcoal canister and fuel tank, check for stuck open EVAP VSV. To check EVAP VSV operation, see «EVAP VACUUM SWITCHING VALVE»(ref-63407-S20399202732001020500000).
10. With pressure still applied at EVAP service port, remove fuel tank cap and note pressure reading. Pressure should decrease when fuel tank cap is removed. If pressure decreases when fuel tank cap is removed, remove pressure gauge and hose crimper. Go to next step. If pressure does not decrease when fuel tank cap is removed, remove pressure gauge and hose crimper. Check for restricted vacuum hose between EVAP service port, charcoal canister and fuel tank. Repair or replace vacuum hose as necessary.
11. To check airtightness of fuel tank and fuel inlet pipe, disconnect EVAP line hose from charcoal canister. Perform STEP 2 in illustration. (Scheme 259)and (Scheme 262). Apply.58 psi (.040 kg/cm 2 ) air pressure to EVAP line hose so pressure inside fuel tank is.58 psi (.040 kg/cm 2 ). Check that pressure inside fuel tank holds steady for one minute.
12. If pressure inside fuel tank holds steady for one minute, reinstall EVAP line hose on charcoal canister. Go to next step. If pressure inside fuel will not hold steady for one minute, check for leaking hoses or pipes at fuel tank and fuel inlet pipe, or for leaks at fuel tank or installed components on fuel tank. If no leaks exist, replace fuel tank and fuel inlet pipe. Reinstall EVAP line hose on charcoal canister. Go to next step.
13. To check overfill check valve and cut-off valve, disconnect purge line hose and EVAP line hose from charcoal canister. Install cap on air drain hose or cap on air drain hose fitting on charcoal canister. Perform STEP 3 in illustration. (Scheme 259)- (Scheme 262).
14. Apply.58 psi (.040 kg/cm 2 ) air pressure to purge line hose fitting on charcoal canister. Perform STEP 3 in illustration. (Scheme 259)- (Scheme 262). Ensure air flows from EVAP line hose when air pressure is applied to purge line hose fitting on charcoal canister. If fuel tank is full of fuel, air may not flow from EVAP line hose, as overfill check valve may be closed. Ensure fuel tank is not full of fuel when checking for airflow at EVAP line hose.
15. If air flows from EVAP line hose, go to next step. If air does not flow from EVAP line hose, check for restrictions in EVAP line hose and vent line hose. If any hose is restricted, replace hose and recheck operation. If hoses are not restricted, replace overfill check valve and cut-off valve (if equipped). Overfill check valve and cut-off valve (if equipped) are located on top of fuel tank. (Scheme 242)- (Scheme 244), (Scheme 246) and (Scheme 248).
16. Reinstall purge line hose and EVAP line hose on charcoal canister. To check air inlet line, disconnect air inlet line hose from charcoal canister. Perform STEP 4 in illustration. (Scheme 259)- (Scheme 262). Apply air pressure to air inlet line hose. Air should flow through air inlet line hose. If air flows through air inlet line hose, go to next step. If air does not flow through air inlet line hose, check for restricted air inlet line hose or air inlet line.
17. To check charcoal canister, disconnect necessary electrical connectors and components for removal of charcoal canister. Disconnect purge line hose, EVAP line hose and air inlet line hose from charcoal canister if not previously done.
18. Remove necessary components for access to charcoal canister. Push connector on vent line hose toward charcoal canister, and pinch both sides of retainer on connector, and then disconnect vent line hose with connector from charcoal canister. (Scheme 263)and (Scheme 264).
19. Remove vapor pressure sensor bolts/nut (if equipped) and charcoal canister bolts/nuts. Remove charcoal canister. Inspect charcoal canister for cracks or damage. If charcoal canister is okay, go to next step. If charcoal canister is defective, replace charcoal canister.
20. On Camry gasoline models, Camry Solara, Celica and MR2 and RAV4, install cap on vent port on charcoal canister. (Scheme 265) On Corolla, install hose and cap on vent port. (Scheme 265) On all models, apply.26 psi (.018 kg/cm 2 ) air pressure to EVAP port while holding purge port closed. (Scheme 265) Ensure air flows freely from air drain port.
21. Apply.26 psi (.018 kg/cm 2 ) air pressure to EVAP port while holding air drain port and purge port closed. (Scheme 265) Ensure air does not flow from air inlet port.
22. Using vacuum pump, apply 1.01 in. Hg of vacuum to purge port. (Scheme 265) Ensure vacuum does not decrease when air inlet port is closed and that vacuum decreases when air inlet port is opened.
23. While holding air inlet port closed, use vacuum pump to apply 1.01 in. Hg of vacuum to EVAP port. (Scheme 265) Ensure air flows into purge port. Remove hose (if used) and cap from vent port. Replace charcoal canister if defective.
24. Reinstall charcoal canister. If fuel EVAP system operates properly, it may be necessary to check operation of EVAP VSV, canister closed valve Vacuum Switching Valve (VSV), pressure switching valve Vacuum Switching Valve (VSV) and vapor pressure sensor. See «EVAP VACUUM SWITCHING VALVE»(ref-63407-S20399202732001020500000), «CANISTER CLOSED VALVE VACUUM SWITCHING VALVE»(ref-63407-S38301034262001020500000), «PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE»(ref-63407-S08666638982001020500000) and appropriate «VAPOR PRESSURE SENSOR»(ref-63407-S18826964682001020500000) procedure.

Canister Closed Valve Vacuum Switching Valve (Prius)

Scheme 266

1. Manufacturer states to remove fuel tank for access to Canister Closed Valve Vacuum Switching Valve (CCV VSV) as it is mounted on top of fuel tank. (Scheme 247)
2. Remove fuel tank. See FUEL PUMP under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article for removal of fuel tank. Disconnect necessary hoses and electrical connectors for removal of CCV VSV and fresh air valve. Remove bolt and separate fresh air valve from CCV VSV. (Scheme 247) Remove bolts for CCV VSV and remove CCV VSV along with trap filter. Remove bolts and separate trap filter from CCV VSV.
3. Using ohmmeter, check that continuity exists between electrical terminals on CCV VSV and that resistance is 25-30 ohms at 68°F (20°C). Replace CCV VSV if no continuity exists or resistance is not within specification.
4. Using ohmmeter, ensure no continuity exists between each electrical terminal and body of CCV VSV. Replace CCV VSV if continuity exists between electrical terminal and body of CCV VSV.
5. To test CCV VSV operation, apply air pressure to port "A". Ensure air flows from port "B". Perform STEP 1 in illustration. (Scheme 266)
6. Apply battery voltage and ground to electrical terminals on CCV VSV. Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2 in illustration. (Scheme 266) Replace CCV VSV if defective. Reinstall CCV VSV and fuel tank.

Charcoal Canister

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

Cut-Off Valve (Camry Gasoline Models, Camry Solara, Celica, Corolla, ECHO, Highlander, MR2, Prius & RAV4)

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

1. Remove EVAP Vacuum Switching Valve (VSV). See «EVAP VACUUM SWITCHING VALVE LOCATION»(ref-63407-S37681801122001020500000) table. (Scheme 242)- (Scheme 250). EVAP VACUUM SWITCHING VALVE LOCATION Application Location Camry Gasoline Models & Camry Solara On Bracket Near Air Cleaner Housing & Driver's Side Strut Tower, & Contains Black 2-Pin Electrical Connector With Violet/White & Black/Yellow Wires Celica On Bracket At Rear Of Air Cleaner Housing & Contains Black 2-Pin Electrical Connector With Green/Orange & Black/White Wires Corolla On Bracket At Rear Of Air Cleaner Housing & Contains Black 2-Pin Electrical Connector With Blue/Black & Black Wires ECHO On Bracket At Inside Of Air Cleaner Housing & Contains Blue 2-Pin Electrical Connector With Black/Yellow & White/Green Wires Highlander On Rear Of Air Cleaner Housing & Contains Blue 2-Pin Electrical Connector With Black/White & Black/Red Wires MR2 On Air Intake Hose, Near Air Cleaner Assembly & Contains Blue 2-Pin Electrical Connector With Black/Red & White Wires Prius At Passenger's Side Front Corner Of Engine Compartment, Near Air Intake Hose & Contains Blue 2-Pin Electrical Connector With Red/Blue & Black Wires RAV4 On Air Intake Hose, Near Air Cleaner Assembly & Contains Black 2-Pin Electrical Connector With Black/Red & Pink Wires Tacoma Bolted To End Of Charcoal Canister & Contains Black 2-Pin Electrical Connector With White/Red & White/Green Wires
2. Using ohmmeter, ensure continuity exists between electrical terminals on EVAP VSV and that resistance is within specification. See «EVAP VACUUM SWITCHING VALVE RESISTANCE»(ref-63407-S11376627772001020500000) table. Replace EVAP VSV if no continuity exists or resistance is not within specification. EVAP VACUUM SWITCHING VALVE RESISTANCE Application Ohms @ 68°F (20°C) Camry Gasoline Models & Camry Solara 30-34 Celica, Corolla ECHO, MR2 & Prius 27-33 Highlander, RAV4 & Tacoma 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 267)- (Scheme 269).
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 267)- (Scheme 269). Replace EVAP VSV if defective.

Scheme 267

Scheme 268

Scheme 269

Overfill Check Valve (Camry Gasoline Models, Camry Solara, Celica, Corolla, ECHO, Highlander, MR2, Prius & RAV4)

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 (Camry Gasoline Models, Camry Solara, Celica, Corolla, Highlander, MR2 & RAV4)

1. Remove pressure switching valve Vacuum Switching Valve (VSV). See «PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE LOCATION»(ref-63407-S28630934672001020500000) table. (Scheme 242)- (Scheme 248). PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE LOCATION Application Location Camry Gasoline Models 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 Blue 2-Pin Electrical Connector With White/Red & Red Wires Celica On Bracket At Charcoal Canister Near Fuel Tank & Contains Blue 2-Pin Electrical Connector With Green/Orange & Black/White Wires Corolla On Bracket At Charcoal Canister Near Fuel Tank & Contains Black 2-Pin Electrical Connector With Red & Black Wires Highlander On Bracket At Charcoal Canister Near Fuel Tank & Contains Blue 2-Pin Electrical Connector With White & Green/Yellow Wires MR2 Below Driver's Side Luggage Compartment, On Bracket At Charcoal Canister Near Fuel Tank & Contains Blue 2-Pin Electrical Connector With Blue/White & Black/Red Wires RAV4 On Bracket At Charcoal Canister Near Fuel Tank & Contains Blue 2-Pin Electrical Connector With Green/Orange & Black/Red 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 VACUUM SWITCHING VALVE RESISTANCE»(ref-63407-S29278594052001030200000) table. Replace pressure switching valve VSV if no continuity exists or resistance is not within specification. PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE RESISTANCE Application Ohms @ 68°F (20°C) Camry Gasoline Models, Camry Solara & Celica (1) Corolla 37-44 Highlander, MR2 & RAV4 30-36 (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 270)and (Scheme 271).
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 270)and (Scheme 271). Replace pressure switching valve VSV if defective.

Scheme 270

Scheme 271

Purge Flow Switching Valve Vacuum Switching Valve (Prius)

1. Remove purge flow switching valve Vacuum Switching Valve (VSV). Purge flow switching valve VSV is located on bracket at charcoal canister on top of fuel tank and contains Blue 2-pin electrical connector with Black and Black/Red wires. (Scheme 247) If necessary to remove fuel tank for access to purge flow switching valve VSV, see FUEL PUMP under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article for removal of fuel tank.
2. Using ohmmeter, ensure continuity exists between electrical terminals on purge flow switching valve VSV and that resistance is 33-39 ohms at 68°F (20°C). Replace purge flow switching valve VSV if no continuity exists or resistance is not within specification.
3. Ensure no continuity exists between each electrical terminal and body of purge flow switching valve VSV. Replace purge flow switching valve VSV if continuity exists between electrical terminal and body of purge flow switching valve VSV.
4. To test purge flow switching valve VSV operation, apply air pressure to port "E". Ensure air flows from port "F" and not from port "G". Perform STEP 1 in illustration. (Scheme 272)
5. Apply battery voltage and ground to electrical terminals on purge flow switching valve VSV. Apply air pressure to port "G". Ensure air flows from port "F" and not from port "E". Perform STEP 2 in illustration. (Scheme 272) Replace purge flow switching valve VSV if defective.

Scheme 272

Scheme 273

Scheme 274

Scheme 275

Scheme 276

Scheme 277

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, disconnect electrical connector from vapor pressure sensor. See «VAPOR PRESSURE SENSOR LOCATION»(ref-63407-S39128105172001020500000) table. (Scheme 242), (Scheme 244), (Scheme 246) and (Scheme 248) - (Scheme 250). For additional information for obtaining access to vapor pressure sensor, see VAPOR PRESSURE SENSOR under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. VAPOR PRESSURE SENSOR LOCATION Application Location Camry Gasoline Models 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 Blue/Red, Brown & Yellow Wires Corolla On Charcoal Canister, Near Fuel Tank & Contains Black 3-Pin Electrical Connector With Brown, Blue & Yellow Wires MR2 On Top Of Fuel Pump Assembly On Fuel Tank, Below Cover Plate & Luggage Compartment Boxes Behind Seats, & Contains Black 3-Pin Electrical Connector With Brown, Blue/Red & Green/Black Wires RAV4 On Top Of Fuel Pump Assembly On Fuel Tank, Below Cover Plate & Driver's Side Rear Seat, & Contains Black 3-Pin Electrical Connector With Brown, Yellow & Blue/Black Wires Tacoma On Firewall, Above Brake Booster & Contains Black 3-Pin Electrical Connector With Light Green, Green/Yellow & Red/Yellow 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 273)and (Scheme 274). 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 WIRING DIAGRAMS article. See «ENGINE CONTROL MODULE LOCATION»(ref-63407-S27270922352001020500000) table.
4. On Camry Gasoline Models, Camry Solara, Corolla and Tacoma, to test vapor pressure sensor output voltage, turn ignition on. Disconnect proper vacuum hose from vapor pressure sensor. (Scheme 275)- (Scheme 277). On MR2 and RAV4, to test vapor pressure sensor output voltage, turn ignition on. Remove retaining clip and remove vapor pressure sensor from top of fuel pump assembly. On all models, obtain access to Engine Control Module (ECM). See «ENGINE CONTROL MODULE LOCATION»(ref-63407-S27270922352001020500000) table. ENGINE CONTROL MODULE LOCATION Model (1) Location Camry Gasoline Models & Camry Solara Behind Glove Box Corolla Behind Stereo On Instrument Panel, Just In Front Of Center Console MR2 On Inside Of Firewall, Directly Behind Driver's Seat & Luggage Compartment RAV4 Near Passenger's Side Kick Panel, Just Below Instrument Panel Tacoma Behind Glove Box (1) For illustration of ECM location, see THEORY & OPERATION article. For information on accessing ECM, see ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
5. Connect voltmeter between specified ECM terminals. (Scheme 278)- (Scheme 282). See «ECM TERMINAL APPLICATION»(ref-63407-S07803429592001020500000) table. ECM TERMINAL APPLICATION Application & Terminal Wire Color Camry Gasoline Models E2 Brown PTNK Pink Camry Solara E2 Brown PTNK Blue/Red Corolla E2 Brown PTNK Blue MR2 E2 Brown PTNK Green/Black RAV4 E2 Brown PTNK (1) Blue/Black Or White Tacoma E2 Light Green PTNK Red/Yellow (1) There are 2 different wiring harnesses used. Wire color at designated terminal may vary according to wiring harness used.
6. On Camry gasoline models, Camry Solara, Corolla and Tacoma, using vacuum pump, apply.59 in. Hg of vacuum to disconnected vacuum hose port on vapor pressure sensor and note vapor pressure sensor output voltage. On MR2 and RAV4, using vacuum pump, apply.59 in. Hg of vacuum to air passage on vapor pressure sensor and note vapor pressure sensor output voltage. (Scheme 274) On all models, ensure vapor pressure sensor output voltage is within specification. See «VAPOR PRESSURE SENSOR OUTPUT VOLTAGE»(ref-63407-S41839224232001020500000) 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-63407-S41839224232001020500000) table.
8. Apply.22 psi (.015 kg/cm 2 ) of pressure 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-63407-S41839224232001020500000) table. Replace vapor pressure sensor if vapor pressure sensor output voltage is not within specification. Turn ignition off.

VAPOR PRESSURE SENSOR OUTPUT VOLTAGE

Scheme 278

Scheme 279

Scheme 280

Scheme 281

Scheme 282

Scheme 283

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, remove rear seat cushion and cover plate for access to electrical connector at vapor pressure sensor. On Celica, vapor pressure sensor is located on top of fuel pump assembly on top of fuel tank and contains Black 3-pin electrical connector with Brown, Red and Blue/Black wires. (Scheme 283) On ECHO, vapor pressure sensor is located on top of fuel pump assembly on top of fuel tank and contains Black 3-pin electrical connector with Brown, Red/White and Black wires. (Scheme 283)
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 283) 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 Celica, ECM is located in engine compartment, below cover, just in front of battery, next to driver's side strut tower. On ECHO, ECM is located behind glove box. On all models, for illustration of ECM location, see THEORY & OPERATION article. For information on accessing ECM, see ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER 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 283)
5. Vapor pressure sensor output voltage should be 3.0-3.6 volts. Replace vapor pressure sensor if vapor pressure sensor output voltage is not within specification. Turn ignition off. Reinstall fuel tank cap, cover plate and rear seat cushion.

Vapor Pressure Sensor (Highlander)

Testing information is not available from manufacturer.

Vapor Pressure Sensor (Prius)

Scheme 284

1. Ensure ignition is off. To test vapor pressure sensor supply voltage, disconnect electrical connector at vapor pressure sensor. Vapor pressure sensor is located on top of fuel tank and contains Black 3-pin electrical connector with Brown, Blue/Red and Yellow/Red wires. (Scheme 284) It may be necessary to lower fuel tank for access to electrical connector at vapor pressure sensor.
2. 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 284) 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. ECM is located behind glove box. 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 284)
5. Vapor pressure sensor output voltage should be 3.0-3.6 volts. Replace vapor pressure sensor if vapor pressure sensor output voltage is not within specification. Turn ignition off. Reinstall fuel tank cap.

Vapor Pressure Sensor Vacuum Switching Valve (Tacoma)

1. Remove vapor pressure sensor Vacuum Switching Valve (VSV) from top of charcoal canister. (Scheme 249)and (Scheme 250).
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. 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 285)
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 285) Replace vapor pressure sensor VSV if defective.

Scheme 285

POSITIVE CRANKCASE VENTILATION

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

1. Remove Positive Crankcase Ventilation (PCV) valve. (Scheme 241)- (Scheme 250). Apply air pressure to PCV valve at bottom (cylinder head side) of PCV valve. Ensure air flows easily through PCV valve.
2. 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.

1. Remove Positive Crankcase Ventilation (PCV) valve. PCV valve is located at passenger's side front corner of valve cover, just above intake manifold. Apply air pressure to PCV valve at bottom (cylinder head side) of PCV valve. Ensure air flows easily through PCV valve.
2. 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.

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 and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. With engine idling, disconnect and plug vacuum hose at throttle opener. (Scheme 286) Increase engine speed to 2500 RPM. Release throttle and note engine speed. Engine speed should be 1300-1500 RPM with electric cooling fan off.
3. If engine speed is not within specification, loosen lock nut and rotate throttle opener adjusting screw until correct engine speed is obtained. (Scheme 287) Tighten lock nut. Reinstall vacuum hose on throttle opener.

Scheme 286

Scheme 287

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. With engine idling, disconnect and plug vacuum hose at throttle opener. (Scheme 288) Note engine speed with vacuum hose disconnected from throttle opener. Engine speed should be 1200-1500 RPM.
3. Throttle opener is nonadjustable. 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.

Scheme 288

VARIABLE VALVE LIFT SYSTEM

Note. Variable Valve Lift (VVL) system may also be referred to as Variable Valve Timing Lift Intelligent (VVTL-I or VVTL-i) system.

Note. VVL system is used only on Celica 1.8L 2ZZ-GE. If problem exists in VVL 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 LIFT OIL CONTROL VALVE

Note. Variable Valve Lift (VVL) oil control valve may also be referred to as VVL Oil Control Valve (OCV) or camshaft timing oil control valve (VVL).

Celica 1.8L 2ZZ-GE

1. Remove No. 2 cylinder head cover located on top of engine, above ignition coils and valve cover. To check VVL oil control valve resistance, disconnect electrical connector at VVL oil control valve. VVL oil control valve is located at intake manifold side of cylinder head, near flywheel end of engine. (Scheme 289)
2. Using ohmmeter, check resistance between electrical terminals on VVL 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 VVL oil control valve.
3. To check VVL oil control valve operation, remove VVL oil control valve. See VARIABLE VALVE LIFT OIL CONTROL VALVE under VARIABLE VALVE LIFT SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
4. Note movement of valve inside VVL oil control valve while applying and disconnecting battery voltage and ground to terminals No. 1 and 2 on VVL oil control valve. (Scheme 295) 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 295) Replace VVL oil control valve if operation is not as specified.

VARIABLE VALVE TIMING SYSTEM

Note. Variable Valve Timing (VVT) system is used on Celica, Corolla, ECHO, Highlander, MR2, Prius & RAV4. 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.

Note. Variable Valve Timing (VVT) sensor may also be referred to as camshaft position sensor.

For VVT sensor testing, see CAMSHAFT POSITION SENSOR under IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article.

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.

1. Remove No. 2 cylinder head cover located on top of engine, above ignition coils and valve cover (if necessary) for access to VVT camshaft timing oil control valve. VVT camshaft timing oil control valve is located at intake manifold side of cylinder head, near timing chain end of engine. (Scheme 289)- (Scheme 294).. To check VVT camshaft timing oil control valve resistance, disconnect electrical connector at VVT camshaft timing oil control valve.
2. Using ohmmeter, check resistance between electrical terminals on VVT camshaft timing oil control valve. Ensure resistance is within specification. See «VVT CAMSHAFT TIMING OIL CONTROL VALVE RESISTANCE»(ref-63407-S25442972402001020500000) table. If resistance is within specification, go to next step. If resistance is not within specification, replace VVT camshaft timing oil control valve. VVT CAMSHAFT TIMING OIL CONTROL VALVE RESISTANCE Application Ohms @ 68°F (20°C) Celica, Corolla, Highlander, MR2, Prius & RAV4 6.9-7.9 ECHO 5.5-12.0
3. To check VVT camshaft timing oil control valve operation, remove VVT camshaft timing oil control valve. See VARIABLE VALVE TIMING CAMSHAFT TIMING OIL CONTROL VALVE under VARIABLE VALVE TIMING SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
4. Note movement of 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 295)and (Scheme 296). 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 295)and (Scheme 296). Replace VVT camshaft timing oil control valve if operation is not as specified.

Scheme 289

Scheme 290

Scheme 291

Scheme 292

Scheme 293

Scheme 294

Scheme 295

Scheme 296