Engine Controls - System & Component Testing - 4-CYLINDER: Other Toyota Celica T230

Celica

Note. ACIS VSV may also be referred to as intake air control valve system VSV.

Scheme 60

Scheme 61

1. Remove necessary components for access to ACIS VSV. ACIS VSV is located on bottom of air cleaner case. (Scheme 60)
2. Remove ACIS VSV. Using ohmmeter, ensure continuity exists between electrical terminals on ACIS VSV and 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 61)
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 61) Replace ACIS VSV if defective. Reinstall ACIS VSV.

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

Scheme 62

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 is properly adjusted, go to next step. If A/C compressor drive belt requires adjustment, adjust drive belt to specification 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-2892-S15202143512000041400000) 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. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 80)and (Scheme 81). Connect oscilloscope between proper terminals on ECM for A/C compressor lock sensor. See «ECM TERMINAL IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR»(ref-2892-S16791749012000041400000) table. These are the LCK1 and E1 terminals at ECM. ECM TERMINAL IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR Application ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E7 26 (White/Blue) E6 17 (Brown) Gasoline Models With Engine Immobilizer E11 25 (White/Blue) E10 17 (Brown) Without Engine Immobilizer E11 26 (White/Blue) E10 17 (Brown) Camry Solara With Engine Immobilizer E11 25 (White/Blue) E10 17 (Brown) Without Engine Immobilizer E11 26 (White/Blue) E10 17 (Brown)
5. 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 62) 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.
6. Check wiring harness and electrical connectors between ECM and A/C compressor lock sensor. See WIRING DIAGRAMS in MANUAL A/C-HEATER SYSTEMS - CAMRY & CAMRY SOLARA article in AIR CONDITIONING & HEATING. 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.

Camry CNG & Gasoline Models, Camry Solara, Celica & ECHO

Testing information is not available from manufacturer.

Scheme 63

1. If using scan tool, go to next step. If scan tool is not available, go to step 10.
2. Connect scan tool to data link connector No. 3. (Scheme 75) Turn ignition on. Turn scan tool on. Start engine and turn A/C on. Ensure A/C clutch engages.
3. Select ACTIVE TEST MODE on scan tool. Check operation of A/C clutch when A/C-cut control is operated by scan tool. A/C clutch should turn off (stop operating) when A/C-cut control is operated by scan tool. If A/C clutch does not operate properly, go to next step. If A/C clutch operates properly, shut engine off. Remove scan tool. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
4. Check for open or short in wiring harness and electrical connectors between Engine Control Module (ECM) and A/C amplifier. See WIRING DIAGRAMS in MANUAL A/C-HEATER SYSTEMS - COROLLA 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 63) 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 (ECM) 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 83)and (Scheme 84).
7. Start engine. On 3-speed A/T and M/T applications, using voltmeter, check voltage between body ground and terminal No. 21 (Red/Blue wire) at ECM electrical connector E6 while turning A/C switch on and off. (Scheme 83) This is the ACT terminal at ECM. On 4-speed A/T applications, using voltmeter, check voltage between body ground and terminal No. 12 (Red/Blue wire) at ECM electrical connector E10 while turning A/C switch on and off. (Scheme 84) This is the ACT terminal at ECM.
8. On all applications, voltage should be 9-14 volts with A/C switch on, and less than 1.5 volts with A/C switch off. If voltage is as specified, go to next step. If voltage is not as specified, replace A/C amplifier.
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 (ECM) 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 83)and (Scheme 84).
12. Start engine. On 3-speed A/T and M/T applications, using voltmeter, check voltage between body ground and terminal No. 21 (Red/Blue wire) at ECM electrical connector E6 while turning A/C switch on and off. (Scheme 83) This is the ACT terminal at ECM. On 4-speed A/T applications, using voltmeter, check voltage between body ground and terminal No. 12 (Red/Blue wire) at ECM electrical connector E10 while turning A/C switch on and off. (Scheme 84) This is the ACT terminal at ECM.
13. On all applications, voltage should be 9-14 volts with A/C switch on, and less than 1.5 volts with A/C switch off. 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 or short in wiring harness and electrical connectors between ECM and A/C amplifier. See WIRING DIAGRAMS in MANUAL A/C-HEATER SYSTEMS - COROLLA article in AIR CONDITIONING & HEATING. A/C amplifier is located behind instrument panel, just above glove box, near center of glove box area. (Scheme 63) If wiring harness and electrical connectors are okay, replace A/C amplifier. If wiring harness or electrical connector is defective, repair as necessary.

Scheme 64

1. If using scan tool, go to next step. If scan tool is not available, go to step 9.
2. Connect scan tool to data link connector No. 3. (Scheme 77) Turn ignition on. Turn scan tool on. Start engine and turn A/C on. Ensure A/C clutch engages.
3. Select ACTIVE TEST MODE on scan tool. Check operation of A/C clutch when A/C-cut control is operated by scan tool. A/C clutch should turn off (stop operating) when A/C-cut control is operated by scan tool. If A/C clutch does not operate properly, go to next step. If A/C clutch operates properly, shut engine off. Remove scan tool. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
4. Check for open or short in wiring harness and electrical connectors between Engine Control Module (ECM) and A/C amplifier. See WIRING DIAGRAMS in MANUAL A/C-HEATER SYSTEMS - RAV4 article in AIR CONDITIONING & HEATING. ECM is located behind instrument panel, near 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, on top of heater assembly. (Scheme 64) 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 driver-side carpet cover from driver's side of center console for access to ECM. Note ECM electrical connector terminals. (Scheme 83)
6. Start engine. Using voltmeter, check voltage between body ground and terminal No. 21 (Red/Yellow wire) at ECM electrical connector E6 while turning A/C switch on and off. (Scheme 83) This is the ACT terminal at ECM.
7. Voltage should be 9-14 volts with A/C switch on, and less than 1.5 volts with A/C switch off. If voltage is as specified, go to next step. If voltage is not as specified, replace A/C amplifier.
8. 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. Remove driver-side carpet cover from driver's side of center console for access to Engine Control Module (ECM). ECM is located behind instrument panel, near front of center console. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 83)
10. Start engine. Using voltmeter, check voltage between body ground and terminal No. 21 (Red/Yellow wire) at ECM electrical connector E6 while turning A/C switch on and off. (Scheme 83) This is the ACT terminal at ECM.
11. Voltage should be 9-14 volts with A/C switch on, and less than 1.5 volts with A/C switch off. 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.
12. Check for open or short in wiring harness and electrical connectors between ECM and A/C amplifier. See WIRING DIAGRAMS in RAV4 article in MANUAL A/C-HEATER SYSTEMS. A/C amplifier is located behind instrument panel, just above glove box, on top of heater assembly. (Scheme 64) If wiring harness and electrical connectors are okay, replace A/C amplifier. If wiring harness or electrical connector is defective, repair 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 80)and (Scheme 81).
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-2892-S18074473662000041400000) 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.
4. Check A/C evaporator temperature sensor operation. See «A/C EVAPORATOR TEMPERATURE SENSOR»(ref-2892-S31600120622000041400000) 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. 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.

ENGINE CONTROL MODULE (ECM) 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 & Camry Gasoline Models Without Engine Immobilizer

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 80)and (Scheme 81). For CNG models, go to next step. For gasoline models, go to step 3.
2. On CNG models, 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. If wiring harness and electrical connectors are okay, go to step 4. If wiring harness or electrical connector is defective, repair as necessary.
3. On gasoline models, turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Black/Yellow wire) at ECM electrical connector E7 and No. 17 (Brown wire) at ECM electrical connector E10. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E10 and body ground. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
4. On all models, check operation of EFI main relay. See «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. 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 is located in fuse/relay box at driver-side front corner of engine compartment, near battery and air cleaner. 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 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.

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

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 81)
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. 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. 2 (Black/Red wire) at ECM electrical connector E7. This is the IGSW terminal at ECM. Voltage should be 9-14 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step 7.
4. Check for defective IGN fuse. IGN fuse is located in fuse box behind driver's side of instrument panel. If IGN fuse is okay, go to next step. If IGN fuse is defective, repair short in wiring harness and components connected to IGN fuse. See WIRING DIAGRAMS article.
5. Check ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch.
6. Check for open in wiring harness and electrical connectors between battery and ignition switch, and between ignition switch and ECM. See WIRING DIAGRAMS article. Repair wiring harness or electrical connectors as necessary.
7. 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.
8. Check for defective EFI fuse. EFI fuse is located in fuse/relay box at driver-side front corner of engine compartment, near battery and air cleaner. If EFI fuse is okay, go to next step. If EFI fuse is defective, repair short in wiring harness and components connected to EFI fuse. See WIRING DIAGRAMS article.
9. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. If EFI main relay operates properly, go to next step. If EFI main relay is defective, replace EFI main relay.
10. On Camry gasoline models, check for open or 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 or short in White/Black wire between EFI main relay and body ground. See WIRING DIAGRAMS article. On Camry Solara, check for open or short in wiring harness and electrical connectors between terminal No. 8 (Black/Red wire) at ECM electrical connector E7 and EFI main relay, and check 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.
11. Check wiring harness and electrical connectors between battery and EFI fuse. See WIRING DIAGRAMS article. Repair as necessary.

Camry Solara Without Engine Immobilizer

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 81)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 16 (Red wire) at ECM electrical connector E7 and No. 17 (Brown wire) at ECM electrical connector E10. This is the +B and E1 terminals at ECM. Voltage should be 9-14 volts. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If voltage is not within specification, check for open in wiring harness and electrical connectors between terminal No. 17 (Brown wire) at ECM electrical connector E10 and body ground. 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-2892-S41339776852000041400000) under RELAYS. 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-side front corner of engine compartment, near battery and air cleaner. 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 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.

1. Remove cover for access to ECM. ECM is located in engine compartment, below cover, just in front of battery, next to driver-side strut tower. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 82)
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. 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 wiring harness and electrical connectors between battery and ignition switch. See WIRING DIAGRAMS article. If necessary to check AM2 fuse, AM2 fuse is located in fuse/relay box at driver-side front corner of engine compartment, just in front of strut tower, near battery. Repair wiring harness or electrical connectors as necessary.
5. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. 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-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 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-side front corner of engine compartment, just in front of strut tower, near battery. If EFI No. 1 fuse is okay, go to next step. If EFI No. 1 fuse is defective, repair short in wiring harness and components connected to EFI No. 1 fuse. See WIRING DIAGRAMS article.
9. Check 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 ECM. See ENGINE CONTROL MODULE (ECM) 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 83)and (Scheme 84).
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. 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-2892-S41339776852000041400000) under RELAYS. 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-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.
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 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 85)
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. 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-2892-S41339776852000041400000) under RELAYS. 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-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.

RAV4

1. Remove driver-side carpet cover from driver's side of center console for access to ECM. ECM is located behind instrument panel, near front of center console. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 83)
2. Turn ignition on. Using voltmeter, check voltage between terminals No. 12 (Black/White wire) at ECM electrical connector E6 and No. 14 (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. 14 (Brown wire) at ECM electrical connector E4 and body ground. 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-2892-S41339776852000041400000) under RELAYS. 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-side front corner of engine compartment, near 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.
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 at driver-side front corner of engine compartment, near strut tower. 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.

Tacoma

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 86)and (Scheme 87).
2. Turn ignition on. On Calif. emission vehicles, 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. On all except Calif. emission vehicles, using voltmeter, check voltage between terminals No. 12 (White/Red wire) at ECM electrical connector E5 and No. 24 (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. 17 (Brown wire) at ECM electrical connector E7 and body ground on Calif. emission vehicles, or terminal No. 24 (Brown wire) at ECM electrical connector E8 and body ground on except Calif. emission vehicles. 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.
3. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. 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-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 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.

4Runner

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 88)and (Scheme 89).
2. Turn ignition on. On Calif. emission vehicles, using voltmeter, check voltage between terminals No. 16 (White/Blue wire) at ECM electrical connector E8 and No. 17 (Brown wire) at ECM electrical connector E6. On all except Calif. emission vehicles, using voltmeter, check voltage between terminals No. 12 (White/Blue wire) at ECM electrical connector E8 and No. 24 (Brown wire) at ECM electrical connector E5. 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 E6 and body ground on Calif. emission vehicles, or terminal No. 24 (Brown wire) at ECM electrical connector E5 and body ground on except Calif. emission vehicles. 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.
3. Check operation of EFI main relay. See «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. 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-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 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 CNG Models

Note. Fuel injectors on Camry CNG models 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 65

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 80)
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-2892-S26843254882000041400000) 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 65) If voltage is within specification, and fuel injector signal wave pattern and fuel injector duration signal wave pattern are okay, go to step 9. 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. 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-2892-S28324736792000041400000) 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 2.65-3.00 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 or 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-2892-S21342858472000041400000) 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 EGR system test. See «EXHAUST GAS RECIRCULATION (EGR) SYSTEM TEST»(ref-2892-S10769954172000041400000) 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 (ECT) SENSOR»(ref-2892-S25471971852000041400000) and «MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR»(ref-2892-S08811734162000041400000) under ENGINE SENSOR & 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.

Except Camry CNG Models

Testing information is not available from manufacturer.

FUEL PUMP CONTROL CIRCUIT

Camry Gasoline Models, Camry Solara, Celica, Corolla, ECHO & RAV4

1. If using scan tool, go to next step. If scan tool is not available, go to step 3.
2. Check operation of fuel pump by using scan tool. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article. If fuel pump does not operate when using scan tool, go to step 5. If fuel pump operates when using scan tool, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
3. Remove necessary components for access to Engine Control Module (ECM). See «ECM LOCATION»(ref-2892-S12342212762000041400000) table.
4. Note ECM terminals. (Scheme 81)- (Scheme 85). 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 (EXCEPT TACOMA & 4RUNNER)»(ref-2892-S26582857002000041400000) table. On Camry gasoline models, Camry Solara and RAV4, feel for fuel pressure in fuel inlet line at fuel filter when fuel inlet line is pinched closed. On Celica, Corolla and ECHO, feel for fuel pressure in fuel inlet line at end of fuel rail when fuel inlet 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 (ECM) POWER SOURCE CIRCUIT»(ref-2892-S05211063592000041400000). 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-2892-S06264335672000041400000) under RELAYS. 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 «ECM LOCATION»(ref-2892-S12342212762000041400000) table. ECM 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-Side Strut Tower Corolla (2) Behind Stereo On Instrument Panel, Just In Front Of Center Console ECHO Behind Glove Box RAV4 Behind Instrument Panel, Near Front Of Center Console (1) For illustration of ECM location, see THEORY & OPERATION article. (2) It may be necessary to remove bolts from ECM so electrical connectors can be accessed on ECM. See ENGINE CONTROL MODULE (ECM) under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
8. Note ECM terminals. (Scheme 81)- (Scheme 85). Turn ignition on. Using voltmeter, check voltage between body ground and FC terminal at ECM. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (EXCEPT TACOMA & 4RUNNER)»(ref-2892-S26582857002000041400000) table. ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (EXCEPT TACOMA & 4RUNNER) 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) RAV4 E6 14 (Green/Red)
9. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check for open in wiring harness and connectors between ECM and circuit opening relay, ignition switch and circuit opening relay (if applicable) and EFI main relay and circuit opening relay (if applicable). See WIRING DIAGRAMS article. For EFI main relay location, see «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. If wiring harness or electrical connector is defective, repair as necessary.
10. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-2892-S22481532702000041400000) 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. 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.

Tacoma & 4Runner

1. If using scan tool, go to next step. If scan tool is not available, go to step 3.
2. Check operation of fuel pump by using scan tool. See FUEL PUMP OPERATION under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article. If fuel pump does not operate when using scan tool, go to step 5. If fuel pump operates when using scan tool, check start signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-2892-S18690921802000041400000).
3. Remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. Note ECM terminals. (Scheme 86)- (Scheme 89).
4. 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 (TACOMA & 4RUNNER)»(ref-2892-S07544185862000041400000) table. Feel for fuel pressure in fuel return line from fuel pressure regulator when fuel return line is pinched closed. If fuel pump does not operate when jumper wire was connected, go to next step. If fuel pump operates when jumper wire was connected, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-2892-S18690921802000041400000).
5. Check ECM power source circuit. See «ENGINE CONTROL MODULE (ECM) POWER SOURCE CIRCUIT»(ref-2892-S05211063592000041400000). 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-2892-S06264335672000041400000) under RELAYS. If circuit opening relay is okay, go to next step. If circuit opening relay is defective, replace circuit opening relay.
7. Remove glove box for access to ECM if not previously done. Note ECM terminals. (Scheme 86)- (Scheme 89).
8. Turn ignition on. Using voltmeter, check voltage between body ground and FC terminal at ECM. See «ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (TACOMA & 4RUNNER)»(ref-2892-S07544185862000041400000) table. ECM IDENTIFICATION FOR FUEL PUMP FC TERMINAL (TACOMA & 4RUNNER) Application ECM Connector ECM Terminal No. (Wire Color) Tacoma Calif. Emission Vehicles E6 6 (Green/Yellow) Except Calif. Emission Vehicles E8 14 (Green/Yellow) 4Runner Calif. Emission Vehicles E7 6 (Green/Yellow) Except Calif. Emission Vehicles E5 14 (Green/Yellow)
9. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check for open in wiring harness and electrical connectors between EFI main relay and circuit opening relay, and between circuit opening relay and ECM. See WIRING DIAGRAMS article. For EFI main relay location, see «EFI MAIN RELAY»(ref-2892-S41339776852000041400000) under RELAYS. If wiring harness or electrical connector is defective, repair as necessary.
10. Check fuel pump resistance and operation. See «FUEL DELIVERY»(ref-2892-S22481532702000041400000) 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. 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.

FUEL PIPE FUEL PRESSURE SENSOR CIRCUIT

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

Scheme 66

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 80)
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-2892-S15622030212000041400000) 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-2892-S15622030212000041400000) table.
5. Voltage should be as specified in relation fuel gauge reading. See «FUEL PIPE FUEL PRESSURE SENSOR VOLTAGE SPECIFICATIONS»(ref-2892-S42663826282000041400000) 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 or short in wiring harness and electrical connectors between ECM and 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 66)
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 TANK FUEL TEMPERATURE SENSOR CIRCUIT

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

Scheme 67

1. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 80)
2. Turn ignition on. Using voltmeter, check voltage between terminal No. 18 (Brown wire) at ECM electrical connector E6 and terminal 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-2892-S03882252222000041400000) table. FUEL TANK FUEL TEMPERATURE SENSOR VOLTAGE SPECIFICATIONS Temperature Volts -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 67)
5. Check fuel tank fuel temperature sensor. See «FUEL TANK FUEL TEMPERATURE SENSOR»(ref-2892-S22040284962000041400000) 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 or short in wiring harness and electrical connectors between ECM and fuel tank fuel temperature sensor. 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.

Scheme 68

1. If using scan tool, go to next step. If scan tool is not available, go to step 5.
2. Connect scan tool to data link connector No. 3. (Scheme 72)and (Scheme 73). Turn ignition on and then turn scan tool on. Read STA signal display on scan tool with ignition on, and with ignition 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 wiring harness and electrical connectors between ECM and junction connectors J6 and J7. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. 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 68) 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.
5. Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 80)and (Scheme 81). Using voltmeter, check voltage between body ground and STA terminal at ECM with ignition in START position and engine cranking. See «ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA)»(ref-2892-S01164506732000041400000) table. ECM TERMINAL IDENTIFICATION FOR STARTER SIGNAL (CAMRY & CAMRY SOLARA) Application ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E4 15 (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 wiring harness and electrical connectors between ECM and junction connector J6 and J7. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. Junction connectors J6 and J7 are located behind driver's side of instrument panel, near fuse/relay box. (Scheme 68) 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.

Celica & ECHO

Starter signal circuit testing information is not available from manufacturer.

1. If using scan tool, go to next step. If scan tool is not available, go to step 5.
2. Connect scan tool to data link connector No. 3. (Scheme 75) Turn ignition on, and then turn scan tool on. Read STA signal display on scan tool with ignition on, and with ignition 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 wiring harness and electrical connectors between ECM and starter relay. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. 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-side front corner of engine compartment, near strut tower.
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 ECM. See ENGINE CONTROL MODULE (ECM) 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 83)and (Scheme 84).
7. On 3-speed A/T and M/T applications, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E6 with ignition in START position and engine cranking. (Scheme 83) On 4-speed A/T applications, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E9 with ignition in START position and engine cranking. (Scheme 84) On all models, this is the STA terminal at ECM.
8. 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.
9. Check for open in wiring harness and electrical connectors between ECM and starter relay. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. Starter relay is located in fuse/relay box at driver-side front corner of engine compartment, near strut tower.
10. 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 69

1. If using scan tool, go to next step. If scan tool is not available, go to step 5.
2. Connect scan tool to data link connector No. 3. (Scheme 77) Turn ignition on and then turn scan tool on. Read STA signal display on scan tool 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 wiring harness and electrical connectors between ECM and junction connectors J6 and J7. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. ECM is located behind instrument panel, near front of center console. For illustration of ECM location, see THEORY & OPERATION article. Junction connectors J6 and J7 are located near center console. (Scheme 69)
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 driver-side carpet cover from driver's side of center console for access to ECM. ECM is located behind instrument panel, near front of center console. For illustration of ECM location, see THEORY & OPERATION article.
6. Note ECM electrical connector terminals. (Scheme 83) Using voltmeter, check voltage between body ground and terminal No. 11 (Black wire) at ECM electrical connector E6 with ignition in START position and engine cranking. 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 wiring harness and electrical connectors between ECM and junction connectors J6 and J7. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. Junction connectors J6 and J7 are located near center console. (Scheme 69)
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.

Scheme 70

1. If using scan tool, go to next step. If scan tool is not available, go to step 5.
2. Connect scan tool to data link connector No. 3. (Scheme 78) Turn ignition on and then turn scan tool on. Read STA signal display on scan tool 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 wiring harness and electrical connectors between ECM and junction block No. 3. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. Junction block No. 3 is located behind instrument panel. (Scheme 70)
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 ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 86)and (Scheme 87). On Calif. emission vehicles, using voltmeter, check voltage body ground and terminal No. 7 (Black/White wire) at ECM electrical connector E5 with ignition in START position and engine cranking. (Scheme 86) On all except Calif. emission vehicles, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E5 with ignition in START position and engine cranking. (Scheme 87) On all models, this is the STA terminal at ECM.
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 wiring harness and electrical connectors between ECM and junction block No. 3. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. Junction block No. 3 is located behind instrument panel. (Scheme 70)
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 71

1. If using scan tool, go to next step. If scan tool is not available, go to step 5.
2. Connect scan tool to data link connector No. 3. (Scheme 79) Turn ignition on and then turn scan tool on. Read STA signal display on scan tool 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 in wiring harness and electrical connectors between ECM and splice No. 121. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. Splice No. 121 is located behind driver's side of instrument panel. (Scheme 71)
4. If wiring harness, electrical connector or splice are defective, repair as necessary. If wiring harness, electrical connectors and splice 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 ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 88)and (Scheme 89). On Calif. emission vehicles, using voltmeter, check voltage body ground and terminal No. 7 (Black/White wire) at ECM electrical connector E8 with ignition in START position and engine cranking. (Scheme 88) On all except Calif. emission vehicles, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E8 with ignition in START position and engine cranking. (Scheme 89) On all models, this is the STA terminal at ECM.
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 Black/White wire in wiring harness and electrical connectors between ECM and splice No. 121. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. Splice No. 121 is located behind driver's side of instrument panel. (Scheme 71)
8. If wiring harness, electrical connector or splice are defective, repair as necessary. If wiring harness, electrical connectors and splice 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 72

Scheme 73

Scheme 74

Scheme 75

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Power & Ground Circuits

For testing of Engine Control Module (ECM) power and ground circuits, see ENGINE CONTROL MODULE (ECM) POWER SOURCE CIRCUIT. Also see PIN VOLTAGE CHARTS article. For illustration of ECM location, see THEORY & OPERATION article. Use illustration for identification of ECM electrical connector terminals. (Scheme 80)- (Scheme 89).

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Scheme 88

Scheme 89

Scheme 90

1. Disconnect electrical connector for A/C compressor lock sensor. A/C compressor lock sensor is located near front of A/C compressor, and electrical connector is located near generator. (Scheme 90) 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 90) Resistance should be 65-125 ohms at 68°F (20°C). Replace A/C compressor lock sensor if resistance is not within specification. On some models, it may be necessary to replace A/C compressor along with A/C compressor lock sensor if resistance is not within specification.

Scheme 91

1. Remove A/C evaporator temperature sensor. See A/C EVAPORATOR TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
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 91) Replace A/C evaporator temperature if resistance is not within specification at specified temperature.

AIR/FUEL (A/F) SENSOR

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

Scheme 92

Scheme 93

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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing 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 92)and (Scheme 93). Replace A/F sensor if resistance is not.8-1.4 ohms at 68°F (20°C).

Scheme 94

Scheme 95

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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing 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 94)and (Scheme 95). 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, Tacoma & 4Runner

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 96)- (Scheme 98). Resistance should be within specification in relation to temperature. See «AIRFLOW METER RESISTANCE»(ref-2892-S41000608882000041400000) 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 Tacoma & 4Runner -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 99)- (Scheme 101).
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 99)- (Scheme 101). While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Turn ignition off. Remove voltmeter.

Scheme 96

Scheme 97

Scheme 98

Scheme 99

Scheme 100

Scheme 101

BRAKELIGHT SWITCH

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

Camry CNG & Gasoline Models, Celica, Corolla, Tacoma & 4Runner

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on brakelight switch. (Scheme 102)
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 102

Camry Solara & RAV4

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on brakelight switch. (Scheme 103)
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 103

1. Disconnect electrical connector at brakelight switch. Brakelight switch is located near top of brake pedal. Note terminal identification on brakelight switch. (Scheme 104)
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 104

CAMSHAFT POSITION SENSOR

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

CRANKSHAFT POSITION SENSOR

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

Tacoma 2.4L 2RZ-FE Except Calif. Emission Vehicles, Tacoma 2.7L 3RZ-FE & 4Runner

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-2892-S33232445452000041400000) 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, RAV4, Tacoma & 4Runner

1. Ensure ignition is off. Disconnect electrical connector from ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-2892-S13826556392000041400000) 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 on ECT sensor. Heat water and note that resistance is within specification in relation to temperature. (Scheme 106) Replace ECT sensor if resistance is not within specification.

Celica, Corolla & ECHO

1. Ensure ignition is off. Disconnect electrical connector from ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-2892-S13826556392000041400000) 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 105) Heat water and note that resistance is within specification in relation to temperature. (Scheme 106) Replace ECT sensor if resistance is not within specification.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION

Scheme 105

Scheme 106

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 107

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 107)
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 107) 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 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. Note ECM electrical connector terminals. (Scheme 80)
5. Turn ignition on. Using voltmeter, check 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-2892-S00024283982000041400000) 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 108

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 108)
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 108) Fuel rail fuel pressure sensor 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. Note ECM electrical connector terminals. (Scheme 80)
4. Turn ignition on. Using voltmeter, check 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-2892-S01348502072000041400000) 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 109)
3. Heat water and note that resistance is within specification in relation to temperature. See «FUEL TANK FUEL TEMPERATURE SENSOR RESISTANCE»(ref-2892-S09145659252000041400000) 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 109

HEATED OXYGEN SENSOR

See OXYGEN SENSOR .

Camry CNG & Gasoline Models, Camry Solara & RAV4

1. Ensure ignition is off. Disconnect electrical connector from intake air temperature sensor. Intake air temperature sensor is located on top cover of air filter 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 106) Replace intake air temperature sensor if resistance is not within specification.

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

KNOCK SENSOR

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

Scheme 110

Scheme 111

Scheme 112

Scheme 113

Scheme 114

1. Knock sensor is located on side of cylinder block. (Scheme 110)- (Scheme 114). 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 MAP sensor supply voltage, disconnect electrical connector from MAP sensor. See «MAP SENSOR LOCATION»(ref-2892-S30060707882000041400000) table. (Scheme 115)and (Scheme 116). MAP SENSOR LOCATION Application Location Camry CNG & Gasoline Models, & Camry Solara In Engine Compartment, On Center Of Firewall RAV4 In Engine Compartment, On Firewall, Near Battery
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 117) 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.
5. On Camry CNG and gasoline models, and Camry Solara, 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 80)and (Scheme 81). Go to step 7.
6. On RAV4, remove driver-side carpet cover from driver's side of center console for access to ECM. ECM is located behind instrument panel, near front of center console. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. (Scheme 83) Go to next step.
7. On all models, connect voltmeter between ECM terminals E2 and PIM. See «ECM TERMINAL IDENTIFICATION FOR MAP SENSOR»(ref-2892-S30610449622000041400000) table. (Scheme 80), (Scheme 81) and (Scheme 83). 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) RAV4 E2 E5 9 (Brown) PIM E5 2 (Light Green/Black)
8. Measure and record MAP sensor output voltage under ambient atmospheric pressure. Attach vacuum pump to bottom of MAP sensor.
9. Apply vacuum in specified increments and measure MAP sensor output voltage drop at each increment. See «MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS»(ref-2892-S42329286812000041400000) table. Turn ignition off. Replace MAP sensor if MAP sensor output voltage drop is not within specification.

MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS

Scheme 115

Scheme 116

Scheme 117

Camry CNG Models, Camry Gasoline Models With Calif. Emissions & Camry Solara Calif. Emission Vehicles

1. A heated Air/Fuel (A/F) sensor is mounted on exhaust manifold. For testing of A/F sensor, see «AIR/FUEL (A/F) SENSOR»(ref-2892-S06733983132000041400000). 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 bank No. 1 sensor No. 2, disconnect electrical connector for heated oxygen sensor. Electrical connector is a Dark Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 118)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 118) 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Camry Gasoline Models Except Calif. Emission Vehicles & Camry Solara Except Calif. Emission Vehicles

1. A heated oxygen sensor is mounted near exhaust manifold. This 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 oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on any oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. Electrical connector for bank No. 1 sensor No. 1 is located near upper radiator hose. (Scheme 119) Electrical connector for bank No. 1 sensor No. 2 is a Dark Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 118)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 118)and (Scheme 119). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Scheme 118

Scheme 119

Scheme 120

Scheme 121

1. Two oxygen sensors are used. One oxygen sensor is mounted on exhaust pipe in front of front catalytic converter. This oxygen sensor is referred to as bank No. 1 sensor No. 1, or front oxygen sensor. Another 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 any 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 120) Electrical connector for bank No. 1 sensor No. 2 is a Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 121)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 120)and (Scheme 121). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. If problem exists with either oxygen sensor or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

1. A heated oxygen sensor is mounted on exhaust pipe in front of catalytic converter. This 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 oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on any 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 122) Electrical connector for bank No. 1 sensor No. 2 is a Dark Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 123)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 122)and (Scheme 123). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Scheme 122

Scheme 123

1. A heated oxygen sensor is mounted on exhaust pipe in front of catalytic converter. This 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 oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on any 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 pipe. (Scheme 124) Electrical connector for bank No. 1 sensor No. 2 is a Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 125)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 124)and (Scheme 125). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Scheme 124

Scheme 125

RAV4 Calif. Emission Vehicles

1. A heated Air/Fuel (A/F) sensor is mounted on exhaust manifold. For testing of A/F sensor, see «AIR/FUEL (A/F) SENSOR»(ref-2892-S06733983132000041400000). 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 bank No. 1 sensor No. 2, disconnect electrical connector for heated oxygen sensor. Electrical connector is a Dark Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 126)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 126) 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

RAV4 Except Calif. Emission Vehicles

1. Heated oxygen sensor is mounted near exhaust manifold. This 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 oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on any 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 127) Electrical connector for bank No. 1 sensor No. 2 is a Dark Gray, 4-pin electrical connector located below passenger-side front seat and carpet, near center console. (Scheme 126)
3. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 126)and (Scheme 127). Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C).
4. 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Scheme 126

Scheme 127

Tacoma Calif. Emission Vehicles & 4Runner Calif. Emission Vehicles

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 (A/F) SENSOR»(ref-2892-S06733983132000041400000). 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 bank No. 1 sensor No. 2, disconnect electrical connector for heated oxygen sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 128)and (Scheme 129). 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Tacoma Except Calif. Emission Vehicles & 4Runner Except Calif. Emission Vehicles

1. A heated oxygen sensor is mounted on exhaust pipe in front of catalytic converter. This 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 oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
2. To test heater resistance on any oxygen sensor, disconnect electrical connector for appropriate heated oxygen sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. (Scheme 128)- (Scheme 131). 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Scheme 128

Scheme 129

Scheme 130

Scheme 131

A/T Models

1. Disconnect electrical connector from PNP switch. PNP switch is mounted on side of transmission/transaxle. Note terminal identification. (Scheme 132)- (Scheme 134).
2. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(ref-2892-S04874666512000041400000) table.
3. If proper continuity does not exist, adjust or replace switch as necessary. For adjustment of PNP switch, see PARK/NEUTRAL POSITION (PNP) SWITCH under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 132

Scheme 133

Scheme 134

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 DTC will be stored in ECM.

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

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

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

Scheme 135

1. Remove PTC heater along with heater core. See POSITIVE TEMPERATURE COEFFICIENT (PTC) HEATER under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
2. To check PTC heater for continuity, using ohmmeter, check that continuity exists between each electrical terminal and ground terminal on PTC heater. (Scheme 135) Replace PTC heater if continuity does not exist between any electrical terminal and ground terminal.
3. To check 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-2892-S28463114892000041400000) table. Replace PTC heater if resistance is not within specification. PTC HEATER RESISTANCE Temperature - °F (°C) Ohms 77 (25) 4800-5200 104 (40) 2550-2850 212 (100) 260-340

Camry CNG & Gasoline Models, Camry Solara, Celica, Corolla, ECHO, Tacoma & 4Runner

1. Ensure ignition is off. Disconnect electrical connector from Throttle Position (TP) sensor on throttle body. Note terminal identification on TP sensor. (Scheme 136)- (Scheme 140).
2. On Camry CNG and gasoline models, Camry Solara, Tacoma and 4Runner, disconnect vacuum hose and apply vacuum to throttle opener. (Scheme 136)and (Scheme 140).
3. On all models, using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-2892-S25363604432000041400000) table. Replace components as necessary if resistance is not within specification.

1. Note location of E2 terminal (Brown wire), VC terminal (Yellow wire) and VTA terminal (Blue/Red wire) on Throttle Position (TP) sensor. Ensure ignition is off. Disconnect electrical connector from TP sensor on throttle body. Disconnect vacuum hose and apply vacuum to throttle opener.
2. Using ohmmeter, check resistance between specified terminals in relation to throttle position. See «THROTTLE POSITION SENSOR RESISTANCE»(ref-2892-S25363604432000041400000) table. Replace components as necessary if resistance is not within specification.

THROTTLE POSITION SENSOR RESISTANCE

Scheme 136

Scheme 137

Scheme 138

Scheme 139

Scheme 140

VARIABLE VALVE TIMING (VVT) SENSOR

Note. VVT sensor may also be referred to as camshaft position sensor.

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

VAPOR PRESSURE SENSOR

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

Scheme 141

Scheme 142

Scheme 143

1. Vehicle speed sensor is mounted on transmission/transaxle and contains a 3-pin electrical connector. (Scheme 141) Connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 142)and (Scheme 143).
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 142)and (Scheme 143).
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.

Scheme 144

Scheme 145

Scheme 146

1. Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a 3-pin electrical connector. (Scheme 144) On Tacoma, electrical connector contains Blue, Green/Red and Pink wires. On 4Runner, electrical connector contains Black/Yellow, Pink/Blue and Gray/Blue wires.
2. On all models, connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. (Scheme 143), (Scheme 145) and (Scheme 146).
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 143), (Scheme 145) and (Scheme 146).
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.

1. The 4WD switch is located on side of transfer case and contains a Gray, 2-pin electrical connector. Remove 4WD switch from transfer case. Connect ohmmeter between electrical terminals on 4WD switch.
2. Push pin on end of 4WD switch inward and ensure continuity exists. No continuity should exist when pin is released (outward) position. Replace 4WD switch if defective.

CIRCUIT OPENING RELAY

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(ref-2892-S33826185932000041400000) table. (Scheme 147)- (Scheme 153). CIRCUIT OPENING RELAY LOCATION (1) Application Location Camry CNG & Gasoline Models, & Camry Solara In Fuse/Relay Box At Driver-Side Front Corner Of Engine Compartment, Near Battery & Air Cleaner Celica In Fuse/Relay Box At Driver-Side Front Corner Of Engine Compartment, Just In Front Of Strut Tower, Near Battery Corolla Center Relay In Relay Box Behind Driver-Side Kick Panel ECHO In Fuse/Relay Box Behind Driver's Side Of Instrument Panel RAV4 Top Rear Relay In Relay Box Below Driver's Side Of Instrument Panel, Behind Kick Panel Tacoma Behind Lower Instrument Panel Cover, Next To Driver's Side Of Steering Column 4Runner Below Right Corner Of Fuse/Relay Box, Behind Lower Instrument Panel Cover At Driver's Side Of Instrument Panel To Left Of Steering Column, Just Above Hood Release Lever (1) Circuit opening relay may be marked as CIR OPN relay.
2. To test circuit opening relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on circuit opening relay. (Scheme 154)- (Scheme 158).
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. (Scheme 154)- (Scheme 158). Replace circuit opening relay if defective.

Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

Scheme 152

Scheme 153

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 154

Scheme 155

Scheme 156

Scheme 157

Scheme 158

1. Ensure ignition is off. Remove EFI main relay. See «EFI MAIN RELAY LOCATION»(ref-2892-S24829403932000041400000) table. EFI MAIN RELAY LOCATION Application Location Camry CNG & Gasoline Models, & Camry Solara In Fuse/Relay Box At Driver-Side Front Corner Of Engine Compartment, Near Battery & Air Cleaner Celica, Corolla & ECHO In Fuse/Relay Box At Driver-Side Front Corner Of Engine Compartment, Just In Front Of Strut Tower, Near Battery RAV4 In Fuse/Relay Box Behind Driver's Side Of Instrument Panel, Next To Steering Column, Or In Fuse/Relay Box At Driver-Side Front Corner Of Engine Compartment, Near Strut Tower Tacoma & 4Runner In Fuse/Relay Box At Driver-Side Front Corner Of Engine Compartment, Next To Battery
2. To test EFI main relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on EFI main relay. (Scheme 154)- (Scheme 158).
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. (Scheme 154)- (Scheme 158). Replace EFI main relay if defective.

HTR SUB1 RELAY

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

Scheme 159

1. Remove HTR SUB1 relay from fuse/relay box located at driver-side front corner of engine compartment, just in front of strut tower, near battery. (Scheme 159)
2. Note terminals on HTR SUB1 relay. (Scheme 159) 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-side front corner of engine compartment, just in front of strut tower, near battery. Testing information is not available from manufacturer. Consult wiring diagram for IG2 relay testing. See WIRING DIAGRAMS article.

Scheme 160

1. Remove IG2 relay from relay box located at driver-side front corner of engine compartment, just in front of strut tower. (Scheme 160)
2. To test IG2 relay continuity, using ohmmeter, check for continuity and no continuity between specified terminals on IG2 relay. see scheme 103
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 103 Replace IG2 relay if defective.

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

See CIRCUIT OPENING RELAY under RELAYS.

See EFI MAIN RELAY under RELAYS.

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 161

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 161)
2. Using ohmmeter, check between electrical terminals on electrical connector for fuel pressure regulator fuel shutoff valve. (Scheme 161) Replace fuel pressure regulator fuel shutoff valve 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, RAV4, Tacoma & 4Runner)

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 162

Scheme 163

1. If using scan tool, go to next step. If scan tool is not available, go to step 4.
2. Connect scan tool to data link connector No. 3. (Scheme 72) Turn ignition on and then turn scan tool on.
3. Select ACTIVE TEST MODE on scan tool. Using scan tool 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 162) If operating sound is heard, fuel tank fuel shutoff valve and wiring circuit are okay. If operating sound is not heard, 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 80)
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 162) 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-side end of fuel tank behind rear seat. (Scheme 163) 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 163) 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 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 fuel injector electrical connector. If fuel injector electrical connector 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-2892-S19866212882000041400000) 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-2892-S00358823392000041400000) under COMPUTERIZED ENGINE CONTROLS.

Fuel Injectors (Camry Gasoline Models, Camry Solara & RAV4)

1. To check for 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 fuel injector electrical connector. If fuel injector electrical connector 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-2892-S19866212882000041400000) 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing 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 164) Tighten union bolt to 22 ft. lbs. (30 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 164)
7. Place vinyl tube on end of fuel injector to prevent fuel spillage. Place fuel injector into a clean graduated container.
8. Connect scan tool to data link connector No. 3. (Scheme 72), (Scheme 73) and (Scheme 77). Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: If scan tool 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-2892-S07636811722000041400000).
9. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 165) 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-2892-S25361173382000041400000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-2892-S25361173382000041400000) table.
10. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop in specified time. See «FUEL INJECTOR LEAKAGE SPECIFICATIONS»(ref-2892-S08805793152000041400000) table. Replace fuel injector if leakage exceeds specified amount. Disconnect negative battery cable. Remove test equipment.
11. Using NEW gaskets, install fuel hose on top of fuel filter. Tighten union bolt to 22 ft. lbs. (30 N.m). Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

Fuel Injectors (Celica, Corolla & ECHO)

1. To check for 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 fuel injector electrical connector. If fuel injector electrical connector 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-2892-S19866212882000041400000) 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing 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. Remove fuel pipe clamp from end of fuel pipe at end of fuel rail if not previously done. Perform STEP 1 in illustration. (Scheme 166)- (Scheme 168). Ensure area around fuel pipe and disconnect fitting is clean.
5. Depress both sides of retainer and pull fuel pipe with disconnect fitting from fuel pipe fitting. Perform STEP 2 in illustration. (Scheme 166)- (Scheme 168).
6. Obtain appropriate fuel pipe. See «FUEL PIPE IDENTIFICATION»(ref-2892-S37091161772000041400000) table. Remove fuel pipe connector from end of NEW fuel pipe. (Scheme 169)and (Scheme 170). 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
7. Remove fuel pipe connector from end of NEW fuel pipe and install on fuel pipe fitting and retainer. (Scheme 171) Ensure fuel pipe connector is securely attached on fuel pipe fitting and retainer is fully seated.
8. Connect delivery hose from Fuel Injector Measuring Set (SST 09268-41047) to fuel pipe connector. 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 171)
9. Place vinyl tube on end of fuel injector to prevent fuel spillage. Place fuel injector into a clean graduated container.
10. Connect scan tool to data link connector No. 3. (Scheme 74)- (Scheme 76). Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: If scan tool 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-2892-S07636811722000041400000).
11. Connect Fuel Injector Tester (09842-30080) to fuel injector for 15 seconds. (Scheme 165) 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-2892-S25361173382000041400000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-2892-S25361173382000041400000) table.
12. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop in specified time. See «FUEL INJECTOR LEAKAGE SPECIFICATIONS»(ref-2892-S08805793152000041400000) table. Replace fuel injector if leakage exceeds specified amount. Disconnect negative battery cable. Remove test equipment.
13. 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 head. DO NOT reuse old retainer. Pull on fuel pipe to ensure fuel pipe is properly locked on fuel pipe fitting.
14. Reinstall fuel pipe clamp. Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

Fuel Injectors (Tacoma & 4Runner)

1. To check for 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 fuel injector electrical connector. If fuel injector electrical connector 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-2892-S19866212882000041400000) 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 SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing 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 172)
5. Install union, delivery hose, gaskets and union bolt from Fuel Injector Measuring Set (SST 09268-41047) on fuel filter. (Scheme 172) Tighten union bolt to 22 ft. lbs. (30 N.m).
6. 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 172)
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 172) 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 scan tool to data link connector No. 3. (Scheme 78)and (Scheme 79). Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: If scan tool 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-2892-S07636811722000041400000).
10. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 165) 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-2892-S25361173382000041400000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-2892-S25361173382000041400000) table.
11. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop in specified time. See «FUEL INJECTOR LEAKAGE SPECIFICATIONS»(ref-2892-S08805793152000041400000) table. Replace fuel injector if leakage exceeds specified amount. Disconnect negative battery cable. Remove test equipment.
12. Using NEW gaskets, install fuel hose on top of fuel filter. Tighten union bolt to 22 ft. lbs. (30 N.m). Reinstall fuel pressure regulator. Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

FUEL INJECTOR RESISTANCE

FUEL INJECTOR VOLUME SPECIFICATIONS

FUEL INJECTOR LEAKAGE SPECIFICATIONS

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Scheme 169

Scheme 170

Scheme 171

Scheme 172

Fuel Cut System

1. Connect scan tool to data link connector No. 3. (Scheme 72)- (Scheme 79). Scan tool is used to read engine RPM. Start engine and warm engine to normal operating temperature.
2. Ensure A/C and all accessories are off. Gradually increase engine RPM to specified RPM. See «FUEL CUT SYSTEM TESTING SPEED»(ref-2892-S34356353662000041400000) table. FUEL CUT SYSTEM TESTING SPEED Application Engine RPM Camry CNG & Gasoline Models, & Camry Solara 2500 Celica, Corolla & ECHO 3500 RAV4 2500 Tacoma & 4Runner 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-2892-S04554186222000041400000) table. Shut engine off. Remove test equipment.

FUEL CUT SYSTEM SPECIFICATIONS (1)

Camry CNG & Gasoline Models, & Camry Solara

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transmission/transaxle in Neutral. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 173)and (Scheme 174). Data link connector is located at passenger's side of engine compartment, near strut tower.
3. Start engine and note engine RPM. 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 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 175) 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 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transmission/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 176) Data link connector No. 3 is located behind driver's side of instrument panel. (Scheme 74)and (Scheme 76).
3. Start engine and note engine RPM. 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 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 177) 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 177)
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-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 178

Scheme 179

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transmission/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 178) Data link connector No. 1 is located at driver's side of engine compartment, near strut tower.
3. Start engine and note engine RPM. 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 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 179) 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 179)
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 (ECM) 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.

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transmission/transaxle in Neutral. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 180) Data link connector No. 1 is located on timing belt end of engine, above generator.
3. Start engine and note engine RPM. 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. Test IAC valve resistance and operation. Go to next step.
4. To test IAC valve resistance, ensure ignition is off. Disconnect electrical connector from IAC valve. IAC valve is located on lower area of throttle body. Using ohmmeter, checking resistance between +B terminal and each remaining terminal on IAC valve. (Scheme 181)
5. Replace IAC valve if resistance is not within specification. See «IAC VALVE RESISTANCE SPECIFICATIONS (RAV4)»(ref-2892-S13942775292000041400000) table. IAC VALVE RESISTANCE SPECIFICATIONS (RAV4) Temperature Ohms Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C).
6. To test IAC valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Apply battery voltage to +B terminal on IAC valve. (Scheme 182) Apply battery ground terminal to proper terminal and ensure valve opens and closes. (Scheme 182) Replace IAC valve if defective.
7. If IAC valve resistance is within specification and operates correctly, check wiring circuit between Engine Control Module (ECM) and IAC valve. ECM is located behind instrument panel, near front of center console. For illustration of ECM location, see THEORY & OPERATION article. See WIRING DIAGRAMS article.

Scheme 180

Scheme 181

Scheme 182

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. Turn ignition off. Apply parking brake and place transmission in Neutral. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. (Scheme 183) Data link connector No. 1 is located on end of intake manifold at front of engine.
3. Start engine and note engine RPM. 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. On Tacoma Calif. emission vehicles, if engine speed is not as specified, turn ignition off and remove jumper wire. Go to next step. On Tacoma except Calif. emission vehicles and 4Runner, if engine speed is not as specified, turn ignition off and remove jumper wire. Go to step 8.
4. On Tacoma Calif. emission vehicles, to test 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 184) 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 Brown/Black 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 184)
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.
8. On Tacoma except Calif. emission vehicles and 4Runner, IAC valve resistance and operation should be tested. To test IAC valve resistance, ensure ignition is off. Disconnect electrical connector from IAC valve. IAC valve is located on lower area of throttle body.
9. Using ohmmeter, checking resistance between +B terminal and each remaining terminal on IAC valve. (Scheme 185) Replace IAC valve if resistance is not within specification. See «IAC VALVE RESISTANCE SPECIFICATIONS (TACOMA EXCEPT CALIF. EMISSION VEHICLES & 4RUNNER)»(ref-2892-S16088575942000041400000) table. IAC VALVE RESISTANCE SPECIFICATIONS (TACOMA EXCEPT CALIF. EMISSION VEHICLES & 4RUNNER) Temperature Ohms Cold (1) 17.0-24.5 Hot (2) 21.5-28.5 (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C).
10. To test IAC valve operation, remove IAC valve from throttle body. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Apply battery voltage to +B terminal on IAC valve. (Scheme 186) Apply battery ground terminal to proper terminal and ensure valve opens and closes. (Scheme 186) Replace IAC valve if defective.
11. If IAC valve resistance is within specification and operates correctly, check wiring circuit between Engine Control Module (ECM) and IAC valve. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. See WIRING DIAGRAMS article.

Scheme 183

Scheme 184

Scheme 185

Scheme 186

THROTTLE BODY

Note. Following procedure is for checking vacuum supply at throttle body. Manufacturer does not list information for checking vacuum supply at throttle body for Celica, Corolla and ECHO.

1. Start engine and allow engine to idle. Note vacuum port location on throttle body. (Scheme 187)- (Scheme 190).
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-2892-S14473079032000041400000) table. Repair or replace components if vacuum supply is not as designated.

THROTTLE BODY VACUUM SUPPLY

Scheme 187

Scheme 188

Scheme 189

Scheme 190

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 191)- (Scheme 197).

Scheme 191

Scheme 192

Scheme 193

Scheme 194

Scheme 195

Scheme 196

Scheme 197

1. Remove cap and filter from top of EGR vacuum modulator. Ensure filter is clean and in good condition. Clean filter with compressed air (if necessary).
2. Reinstall filter and cap. 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 198) Start engine. Ensure engine idles smoothly to ensure proper seating of EGR valve.
3. To test operation of EGR 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 not hot.
4. Test operation of EGR VSV and EGR vacuum modulator. Shut engine off. This test procedure may be performed by using scan tool to operate EGR VSV, or by connecting vacuum hose from port "Q" on EGR vacuum modulator to EGR valve. If using scan tool, go to next step. If scan tool is not available, go to step 6.
5. Connect scan tool to data link connector No. 3. (Scheme 78)and (Scheme 79). Select ACTIVE TEST MODE on scan tool 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 scan tool. 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 198) 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. see scheme 148 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 198

Tacoma 2.4L 2RZ-FE A/T Except Calif. Emission Vehicles & 4Runner With A/T

1. Remove EGR check valve. (Scheme 197) Apply air pressure to Orange side of EGR check valve. Air should flow through EGR check valve.
2. Apply air pressure to Black side of EGR check valve. Air should not flow through EGR check valve. Replace EGR check valve if defective. Reinstall EGR check valve with Orange side of EGR check valve toward EGR vacuum modulator.

See EGR GAS TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES.

EGR VACUUM MODULATOR

Note. When testing EGR vacuum modulator, it may be necessary to monitor engine RPM by using scan tool. Scan tool may be connected to data link connector No. 3 for monitoring engine RPM. (Scheme 72), (Scheme 73), (Scheme 77), (Scheme 78) and (Scheme 79).

Camry CNG & Gasoline Models, Camry Solara, RAV4, Tacoma 2.4L 2RZ-FE Except Calif. Emission Vehicles, Tacoma 2.7L 3RZ-FE & 4Runner

1. Mark vacuum hose locations and disconnect vacuum hoses from EGR vacuum modulator. (Scheme 191), (Scheme 192), (Scheme 196) and (Scheme 197). Block ports "P" and "R" on EGR vacuum modulator. see scheme 148 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.
2. Apply air pressure to port "Q". see scheme 148 Air should flow freely through air filter side of EGR vacuum modulator.
3. Start engine and operate engine at specified RPM. See «EGR VACUUM MODULATOR TESTING SPECIFICATIONS»(ref-2892-S05954341062000041400000) table. Repeat test procedures in steps 1) and 2). 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 199

1. Disconnect electrical connector from EGR VSV. See «EGR VSV LOCATIONS»(ref-2892-S33372479952000041400000) table. (Scheme 191), (Scheme 192) and (Scheme 196). Using ohmmeter, check that continuity exists between electrical terminals on EGR VSV and resistance is 33-39 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists, or resistance is not within specification.
2. 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.
3. To test EGR VSV operation, apply air pressure to port "E". Ensure air flows from port "G". Perform STEP 1 in illustration. (Scheme 199) Apply battery voltage and ground to electrical terminals on EGR VSV.
4. Apply air pressure to port "E". Ensure air flows from filter and not from port "G". Perform STEP 2 in illustration. (Scheme 199) Replace EGR VSV if defective.

Scheme 200

1. Disconnect electrical connector from EGR VSV. See «EGR VSV LOCATIONS»(ref-2892-S33372479952000041400000) table. (Scheme 197) Using ohmmeter, check that continuity exists between electrical terminals on EGR VSV and resistance is 33-39 ohms at 68°F (20°C). Replace EGR VSV if no continuity exists, or resistance is not within specification.
2. 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.
3. To test EGR VSV operation, apply air pressure to port "E". Ensure no air flows from port "F". Perform STEP 1 in illustration. (Scheme 200) Apply battery voltage and ground to electrical terminals on EGR VSV.
4. Apply air pressure to port "E". Ensure air flows from port "F". Perform STEP 2 in illustration. (Scheme 200) Replace EGR VSV if defective.

EGR VSV LOCATIONS

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.

FUEL EVAPORATION SYSTEM

Note. Fuel Evaporative (EVAP) system is not used on Camry CNG models. Fuel Evaporative (EVAP) system may contain different components depending on application. (Scheme 192)- (Scheme 197). When testing fuel EVAP system components, use proper illustration to determine component location.

Note. On Camry gasoline models, Camry Solara, Celica, Corolla and ECHO, 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 192)- (Scheme 195). 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 201

Scheme 202

Scheme 203

Scheme 204

Scheme 205

1. Inspect all 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 to EVAP service port. EVAP service port is located in engine compartment, in purge vacuum hose for EVAP system. (Scheme 192)- (Scheme 194).
3. Operate EVAP Vacuum Switching Valve (VSV). If scan tool is available, go to next step. If scan tool is not available, go to step 5.
4. Connect scan tool to data link connector No. 3. (Scheme 72)- (Scheme 75). Start engine. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate EVAP VSV. Go to step 6.
5. Disconnect electrical connector at EVAP VSV. See «EVAP VSV LOCATION (CAMRY GASOLINE MODELS, CAMRY SOLARA, CELICA & COROLLA)»(ref-2892-S04137782142000041400000) table. (Scheme 192)- (Scheme 194). 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 (CAMRY GASOLINE MODELS, CAMRY SOLARA, CELICA & COROLLA) Application Location Camry Gasoline Models & Camry Solara On Bracket Near Air Filter Housing & Driver-Side Strut Tower, & Contains Black, 2-Pin Electrical Connector With Violet/White & Black/Yellow Wires Celica On Bracket At Rear Of Air Filter Housing & Contains Black, 2-Pin Electrical Connector With Green/Orange & Black/White Wires Corolla On Bracket At Rear Of Air Filter Housing & Contains Black, 2-Pin Electrical Connector With Blue/Black & Black Wires
6. Check vacuum reading on vacuum gauge with engine idling. Vacuum should be.368-19.713 in Hg (or 5-268 in. H2O) for over 5 seconds. If vacuum 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-2892-S27439533412000041400000).
7. Shut engine off. If using scan tool to activate EVAP VSV, stop operation of EVAP VSV. Remove scan tool. 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 201)and (Scheme 202). Charcoal canister is located near fuel tank. (Scheme 192)- (Scheme 194).
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, remove hose crimper. 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-2892-S27439533412000041400000).
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 go to next step. If pressure does not decrease when fuel tank cap is removed, remove pressure gauge and 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 201)and (Scheme 202). 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, and install cap on air drain hose. Perform STEP 3 in illustration. (Scheme 201)and (Scheme 202).
14. Apply.58 psi (.040 kg/cm 2 ) air pressure to purge line hose fitting on charcoal canister. Perform STEP 3 in illustration. (Scheme 201)and (Scheme 202). 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 located on top of fuel tank. (Scheme 192)- (Scheme 194).
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 201)and (Scheme 202). 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 203)and (Scheme 204).
19. Remove vapor pressure sensor retaining bolts/nut (if equipped) and charcoal canister retaining bolts/nuts. Remove charcoal canister. Inspect charcoal canister for cracks or damage at all hose fittings. If charcoal canister is okay, go to next step. If charcoal canister is defective, replace charcoal canister.
20. To check charcoal canister on Camry gasoline models, Camry Solara and Celica, install cap on vent port on charcoal canister. (Scheme 205) To check charcoal canister on Corolla, install hose and cap on vent port. (Scheme 205) On all models, apply.26 psi (.018 kg/cm 2 ) air pressure to EVAP port while holding purge port closed. (Scheme 205) 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 205) Ensure no air flows from air inlet port.
22. Using vacuum pump, apply 1.01 in. Hg of vacuum to purge port. (Scheme 205) 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 205) 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 Vacuum Switching Valve (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-2892-S27439533412000041400000), «CANISTER CLOSED VALVE VACUUM SWITCHING VALVE»(ref-2892-S10455236302000041400000), «PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE»(ref-2892-S39208829342000041400000) and «VAPOR PRESSURE SENSOR»(ref-2892-S28550415922000041400000).

Charcoal Canister

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

Cut-Off Valve (Camry Gasoline Models, Camry Solara, Celica, Corolla & ECHO)

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, RAV4, Tacoma & 4Runner)

1. Remove EVAP Vacuum Switching Valve (VSV). See «EVAP VSV LOCATION»(ref-2892-S15652997362000041400000) table. (Scheme 192)- (Scheme 197). EVAP VSV LOCATION Application Location Camry Gasoline Models & Camry Solara On Bracket Near Air Filter Housing & Driver-Side Strut Tower, & Contains Black, 2-Pin Electrical Connector With Violet/White & Black/Yellow Wires Celica On Bracket At Rear Of Air Filter Housing & Contains Black, 2-Pin Electrical Connector With Green/Orange & Black/White Wires Corolla On Bracket At Rear Of Air Filter Housing & Contains Black, 2-Pin Electrical Connector With Blue/Black & Black Wires ECHO On Bracket At Inside Of Air Filter Housing & Contains Blue, 2-Pin Electrical Connector With Black/Yellow & White/Green Wires RAV4 On Bracket Near Rear Of Air Filter Housing & 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 4Runner Bolted To End Of Charcoal Canister & Contains Black, 2-Pin Electrical Connector With White/Blue & Black/White Wires
2. Using ohmmeter, ensure continuity exists between electrical terminals on EVAP VSV and resistance is within specification. See «EVAP VSV RESISTANCE»(ref-2892-S42631215852000041400000) table. Replace EVAP VSV if no continuity exists, or resistance is not within specification. EVAP VSV RESISTANCE Application Ohms @ 68°F (20°C) Camry Gasoline Models & Camry Solara 30-34 Celica, Corolla & ECHO 27-33 RAV4, Tacoma & 4Runner 30-34
3. 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 206)and (Scheme 207).
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 206)and (Scheme 207). Replace EVAP VSV if defective.

Scheme 206

Scheme 207

Overfill Check Valve (Camry Gasoline Models, Camry Solara, Celica, Corolla & ECHO)

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)

1. Remove pressure switching valve Vacuum Switching Valve (VSV). See «PRESSURE SWITCHING VALVE VSV LOCATION»(ref-2892-S03933550912000041400000) table. (Scheme 192)- (Scheme 194). PRESSURE SWITCHING VALVE VSV 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
2. Using ohmmeter, ensure continuity exists between electrical terminals on pressure switching valve VSV and resistance is 37-44 ohms @ 68°F (20°C). Replace pressure 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 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 208)and (Scheme 209).
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 208)and (Scheme 209). Replace pressure switching valve VSV if defective.

Scheme 208

Scheme 209

Scheme 210

Scheme 211

Scheme 212

Scheme 213

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-2892-S14248534052000041400000) table. (Scheme 192), (Scheme 194), (Scheme 196) and (Scheme 197). 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 RAV4 On Firewall, Above Brake Booster & Contains Black, 3-Pin Electrical Connector With Brown, Yellow & Blue/Yellow Wires Tacoma On Firewall, Above Brake Booster & Contains Black, 3-Pin Electrical Connector With Brown/Black, Green/Yellow & Red/Yellow Wires 4Runner (1) On Firewall, Above Brake Booster & Contains Black, 3-Pin Electrical Connector (1) On Calif. emission vehicles, electrical connector contains Blue/Black, Green/Yellow and Yellow wires. On except Calif. emission vehicles, electrical connector contains Blue/Black, Green/Yellow and Light Green/Black wires.
2. Turn ignition on. Using voltmeter, measure vapor pressure sensor supply voltage between terminals VC and E2 on wiring harness side of electrical connector for vapor pressure sensor. (Scheme 210) 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 not within specification, check wiring circuit. See WIRING DIAGRAMS article. If vapor pressure sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor.
4. To test vapor pressure sensor output voltage, turn ignition on. Disconnect proper vacuum hose from vapor pressure sensor. (Scheme 211)- (Scheme 213). Obtain access to Engine Control Module (ECM). See «ECM LOCATION»(ref-2892-S34298481682000041400000) table. ECM LOCATION Model (1) Location Camry Gasoline Models & Camry Solara Behind Glove Box Corolla (2) Behind Stereo On Instrument Panel, Just In Front Of Center Console RAV4 Behind Instrument Panel, Near Front Of Center Console Tacoma & 4Runner Behind Glove Box (1) For illustration of ECM location, see THEORY & OPERATION article. (2) It may be necessary to remove bolts from ECM so electrical connectors can be accessed on ECM. See ENGINE CONTROL MODULE (ECM) under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
5. Connect voltmeter between specified ECM terminals. (Scheme 214)- (Scheme 217). See «ECM TERMINAL APPLICATION»(ref-2892-S10800585722000041400000) 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 RAV4 E2 Brown PTNK Blue/Yellow Tacoma E2 Brown/Black PTNK Red/Yellow 4Runner E2 Blue/Black PTNK Calif. Emission Vehicles Yellow Except Calif. Emission Vehicles Light Green/Black
6. Using vacuum pump, apply.59 in. Hg of vacuum to vapor pressure sensor. Ensure vapor pressure sensor output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-2892-S25419373002000041400000) table.
7. Release vacuum from vapor pressure sensor. Ensure vapor pressure sensor output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-2892-S25419373002000041400000) table.
8. Apply.22 psi (.015 kg/cm 2 ) of pressure to vapor pressure sensor. Ensure vapor pressure sensor output voltage is within specification. See «VAPOR SENSOR OUTPUT VOLTAGE»(ref-2892-S25419373002000041400000) table. Replace vapor sensor if vapor pressure sensor output voltage is not within specification. Turn ignition off. Reconnect vacuum hose.

VAPOR SENSOR OUTPUT VOLTAGE

Scheme 214

Scheme 215

Scheme 216

Scheme 217

Scheme 218

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 218) 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 218)
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 218) 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 not within specification, check wiring circuit. See WIRING DIAGRAMS article. If vapor pressure sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on vapor pressure sensor.
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 218)
5. Vapor pressure sensor output voltage should be 3.0-3.6 volts. Replace vapor sensor if vapor pressure sensor output voltage is not within specification. Turn ignition off. Reinstall fuel tank cap, cover plate and rear seat cushion.

Vapor Pressure Sensor Vacuum Switching Valve (RAV4, Tacoma & 4Runner)

1. Remove vapor pressure sensor Vacuum Switching Valve (VSV) from top of charcoal canister. (Scheme 196)and (Scheme 197).
2. Using ohmmeter, ensure continuity exists between electrical terminals on vapor pressure sensor VSV and resistance is within specification. See «VAPOR PRESSURE SENSOR VSV RESISTANCE»(ref-2892-S21293259422000041400000) table. Replace vapor pressure sensor VSV if no continuity exists, or resistance is not within specification. VAPOR PRESSURE SENSOR VSV RESISTANCE Application Ohms @ 68°F (20°C) RAV4 33-39 Tacoma & 4Runner 37-44
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 219)
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 219) Replace vapor pressure sensor VSV if defective.

Scheme 219

POSITIVE CRANKCASE VENTILATION (PCV)

1. Remove PCV valve. (Scheme 191)- (Scheme 197). Apply air pressure to PCV valve at cylinder head side of PCV valve. Ensure air flows easily through PCV valve.
2. Apply air pressure to PCV valve at 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.

VARIABLE VALVE LIFT (VVL) SYSTEM

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

Note. If problem exists in VVL system, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

VARIABLE VALVE LIFT (VVL) OIL CONTROL VALVE

Note. 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 220)
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 (VVL) OIL CONTROL VALVE under VARIABLE VALVE LIFT (VVL) 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 224) 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 224) Replace VVL oil control valve if operation is not as specified.

VARIABLE VALVE TIMING (VVT) SYSTEM

Note. If problem exists in VVT system, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving and servicing of DTCs.

Note. VVT sensor may also be referred to as camshaft position sensor.

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

Note. 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 belt end of engine. (Scheme 220)- (Scheme 223). 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-2892-S21374795542000041400000) 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 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 (VVT) CAMSHAFT TIMING OIL CONTROL VALVE under VARIABLE VALVE TIMING (VVT) 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 224)and (Scheme 225). 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 224)and (Scheme 225). Replace VVT camshaft timing oil control valve if operation is not as specified.

Scheme 220

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 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. With engine idling, disconnect and plug vacuum hose at throttle opener. (Scheme 226) 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 (if equipped) and rotate throttle opener adjusting screw until correct engine speed is obtained. (Scheme 227) Tighten lock nut (if equipped). Reinstall vacuum hose on throttle opener.

Scheme 226

Scheme 227

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is within specification. See 4-CYLINDER IDLE SPEED in ON-VEHICLE ADJUSTMENTS - 4-CYLINDER article.
2. With engine idling, disconnect and plug vacuum hose at throttle opener. (Scheme 228) 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 228