Engine Controls - System & Component Testing: Other Lexus RX I

ACOUSTIC CONTROL INDUCTION SYSTEM (ACIS)

Note. All models are equipped with 2 Intake Air Control Valves (IACVs) and 2 ACIS Vacuum Switching Valves (VSVs). No. 1 IACV is located between the air intake chamber and No. 1 and 2 throttle bodies. No 2 IACV is located on front of air intake chamber. IACV VSVs are part of the emission control valve set and is located near air intake chamber.

Intake Air Control Valve

1. Locate ACIS Intake Air Control Valve (IACV) to be tested. No. 1 IACV is located between the air intake chamber and No. 1 and 2 throttle bodies. (Scheme 47) No 2 IACV is located on front of air intake chamber. (Scheme 48) Install a 3-way vacuum "T" fitting in vacuum hose between IACV actuator and ACIS Vacuum Switch Valve (VSV). Connect a vacuum gauge to vacuum "T" fitting. Start engine. With engine idling, ensure vacuum is not present. (Scheme 47)or (Scheme 48).
2. Snap accelerator to Wide Open Throttle (WOT). Ensure vacuum reading momentarily reads about 7.9 in. Hg and IACV actuator rod moves. If vacuum is not as specified or actuator valve rod fails to move, go to next step.
3. Remove IACV. See AIR INDUCTION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Apply about 7.9 in. Hg to IACV actuator. If IACV actuator rod does not move, replace IACV actuator. If IACV actuator rod moves, check to see if diaphragm holds vacuum for at least one minute. If diaphragm does not hold vacuum, replace actuator. If diaphragm holds vacuum, check ACIS vacuum tank. See «ACIS VACUUM TANK»(ref-2784-S30676073392000041300000).

Scheme 47

Scheme 48

Scheme 49

1. Disconnect vacuum hoses from vacuum tank. Vacuum tank is located at left side of engine compartment, under battery tray. Apply air pressure to port "B" on vacuum tank. Ensure air flows from port "A". Perform STEP 1. (Scheme 49) Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2. (Scheme 49) Go to next step.
2. Plug port "B" on vacuum tank. Using vacuum pump, apply 7.9 in. Hg of vacuum to port "A". Perform STEP 3. (Scheme 49) Ensure vacuum reading will hold for at least one minute. Replace vacuum tank if defective and recheck system operation. If vacuum tank is okay, reconnect vacuum hoses. Check ACIS vacuum switching valve. See «ACIS VACUUM SWITCHING VALVE»(ref-2784-S14448663802000041300000).

ACIS Vacuum Switching Valve

1. Remove engine cover and wire harness cover. Remove emission control valve set. (Scheme 50) Disconnect vacuum hoses and electrical connector from ACIS Vacuum Switching Valve (VSV).
2. Remove VSV if necessary. Measure resistance between VSV terminals. If resistance is not 33-39 ohms at 68°F (20°C), replace ACIS VSV. If resistance is 33-39 ohms at 68°F (20°C), check for continuity between VSV case and each terminal at VSV connector (this checks for an internal short). If continuity does not exist, go to next step. If continuity exists, replace VSV.
3. Apply compressed air to VSV port "E". (Scheme 51) Air should flow out of filter, but not out of port "F". Using jumper wires, apply 9-14 volts and ground to VSV terminals. Apply compressed air to VSV port "E". Air should flow out of port "F", but not out of filter. If ACIS VSV does not function as specified, replace ACIS VSV.

Scheme 50

Scheme 51

ECM BACK-UP POWER CIRCUIT (BATTERY)

If circuit or components are faulty, a Diagnostic Trouble Code (DTC) should set. Retrieve DTCs and perform appropriate diagnostic test. See SELF-DIAGNOSTICS - INTRODUCTION article.

ECM POWER SOURCE CIRCUIT (IGNITION KEYED)

ES300

1. Access ECM behind glove box. Turn ignition on. Backprobing connector, connect DVOM negative lead to terminal No. 17 (Brown wire) at ECM E10 connector and positive lead to terminal No. 16 (Black/Yellow wire) at ECM E7 connector. (Scheme 52) If 9-14 volts is present, ECM power circuit is okay. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If 9-14 volts is not present, go to next step.
2. Check for an open circuit in Brown wire between ground and terminal 17 at ECM E10 connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, go to next step.
3. Measure voltage between chassis ground and terminal No. 2 (Black/Red wire) at ECM E7 connector. If 9-14 volts is present, go to step 5. If 9-14 volts is not present, check IGN fuse in instrument panel junction box under left side of instrument panel.
4. If fuse is blown, repair cause of blown fuse. If fuse is okay, check ignition switch. See STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. Replace ignition switch as necessary and retest. If ignition switch is okay, repair open circuit between battery and ignition switch, or between ignition switch and ECM.
5. Turn ignition on. Measure voltage between chassis ground and terminal 8 (Black/White wire) at ECM E7 connector. If 9-14 volts is not present, replace ECM. If 9-14 volts is present, check EFI fuse located in engine compartment fuse/relay box at left front of engine compartment. If fuse is okay, go to next step. If EFI fuse is blown, repair cause of blown fuse.
6. Check EFI main relay located in engine compartment fuse/relay box at left front of engine compartment. See «RELAYS»(ref-2784-S11786245272000041300000) under RELAYS & SOLENOIDS. If EFI main relay is okay, check circuit between chassis ground and terminal No. 8 at ECM E7 connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If circuit is okay, repair circuit between battery and EFI fuse.

Scheme 52

RX300

1. Access ECM behind glove box. Turn ignition on. Backprobing connector, connect DVOM negative lead to terminal No. 17 (Brown wire) at ECM E6 connector and positive lead to terminal No. 16 (Blue/White wire) at ECM E8 connector. (Scheme 53) If 9-14 volts is present, ECM power circuit is okay. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article. If 9-14 volts is not present, go to next step.
2. Check for an open circuit in Brown wire between ground and terminal 17 at ECM E6 connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, go to next step.
3. Measure voltage between chassis ground and terminal No. 2 (Black/Orange wire) at ECM E8 connector. If 9-14 volts is present, go to step 5. If 9-14 volts is not present, check IGN fuse in instrument panel junction box under left side of instrument panel.
4. If fuse is blown, repair cause of blown fuse. If fuse is okay, check ignition switch. See STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. Replace ignition switch as necessary and retest. If ignition switch is okay, repair open circuit between battery and ignition switch, or between ignition switch and ECM.
5. Turn ignition on. Measure voltage between chassis ground and terminal 8 (Black/White wire) at ECM E8 connector. If 9-14 volts is not present, replace ECM. If 9-14 volts is present, check EFI fuse located in engine compartment fuse/relay box at left front of engine compartment. If fuse is okay, go to next step. If EFI fuse is blown, repair cause of blown fuse.
6. Check EFI main relay located in engine compartment fuse/relay box at left front of engine compartment. See «RELAYS»(ref-2784-S11786245272000041300000) under RELAYS & SOLENOIDS. If EFI main relay is okay, check circuit between chassis ground and terminal No. 8 at ECM E8 connector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If circuit is okay, repair circuit between battery and EFI fuse.

Scheme 53

STARTER SIGNAL CIRCUIT

AIR/FUEL RATIO (A/F) SENSOR HEATER RESISTANCE

Note. Bank No. 1 refers to bank which includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. A/F sensor refers to sensor No. 1 in exhaust manifold/pipe in front of catalytic converter.

Disconnect A/F sensor connector to be tested. Measure resistance between terminals B+ and HT of A/F sensor connector. (Scheme 54) Resistance should be.8-1.4 ohms at 68°F (20°C) or 1.8-3.2 ohms at 1472°F (800°C). Replace A/F sensor if resistance is not as specified.

Scheme 54

CAMSHAFT POSITION SENSOR

Camshaft Position (CMP) sensor is also referred to as Variable Valve Timing (VVT) sensor. For VVT sensor testing, see VARIABLE VALVE TIMING SENSOR .

CRANKSHAFT POSITION SENSOR

The Crankshaft Position Sensor (CKP) sensor is a pick-up coil and is mounted next to crankshaft pulley. Turn ignition off. Disconnect CKP sensor connector. Measure resistance between CKP sensor terminals. Replace CKP sensor if resistance is not as specified. See CRANKSHAFT POSITION SENSOR RESISTANCE table.

CRANKSHAFT POSITION SENSOR RESISTANCE

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Ensure ignition is off. Note location of ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(ref-2784-S01453805992000041300000) table. Remove ECT sensor.
2. Place probe end of ECT sensor and thermometer in container of water. Attach ohmmeter between ECT sensor terminals. Heat water and note that resistance is within specification in relation to temperature. (Scheme 55) Replace ECT sensor if resistance is not within specification.
3. Using NEW gasket, install ECT sensor. Tighten ECT sensor to 15 ft. lbs. (20 N.m). Fill cooling system.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION

Scheme 55

HEATED OXYGEN SENSOR HEATER RESISTANCE

Note. Bank No. 1 refers to bank that includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Sensor No. 1 refers to sensor closest to engine block. Sensor No. 2 refers to sensor furthest away from engine block.

Bank No. 1 sensor No. 2 connector is located under driver's seat carpet, next to center counsel. Remove drivers's seat to access connector. Disconnect oxygen sensor connector. Measure resistance between terminals B+ and HT at oxygen sensor connector. (Scheme 54) Replace oxygen sensor if resistance is not 11.0-16.0 ohms.

IAT Sensor Resistance

On all models, IAT sensor is part of Mass Airflow (MAF) sensor. Turn ignition off. Disconnect MAF sensor connector. Measure resistance between MAF sensor terminals THA and E2. (Scheme 56) Replace MAF sensor if resistance is not as specified. See INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE table.

INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE

Scheme 56

Scheme 57

KNOCK SENSOR

Remove knock sensor. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article. Check for continuity between knock sensor terminal and knock sensor body (hex portion). If continuity does not exist, knock sensor is okay. If continuity exists, replace knock sensor.

MAF Sensor Resistance

Disconnect MAF sensor connector. Measure resistance between MAF sensor terminals THA and E2 at MAF sensor. (Scheme 56)or (Scheme 57). Resistance should be as specified. See INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE table. If resistance is not as specified, replace MAF sensor.

MAF Sensor Voltage

Leave MAF sensor connector attached. Turn ignition on. Backprobing, connect voltmeter positive lead to terminal VG and negative lead to terminal E2G at MAF sensor connector. (Scheme 58)or (Scheme 59). Apply compressed air to MAF sensor. If voltage does not fluctuate while applying compressed air to MAF sensor, replace MAF sensor.

Scheme 58

Scheme 59

PARK/NEUTRAL POSITION (PNP) SWITCH

1. If PNP switch is out of adjustment, voltage signals may not be correctly applied to ECM, causing a Diagnostic Trouble Code (DTC) to set. Before assuming PNP switch is faulty, adjust PNP switch. See PARK/NEUTRAL POSITION (PNP) SWITCH under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
2. After switch adjustment is completed, recheck for codes. If DTC does not reset, PNP switch is okay. If DTC resets, remove PNP switch. Check for continuity between specified terminals of PNP switch. See «PNP SWITCH CONTINUITY»(ref-2784-S09469574212000041300000) table. (Scheme 60) If continuity is not as specified, replace PNP switch. If continuity is as specified, install and adjust PNP switch.

PNP SWITCH CONTINUITY

Scheme 60

PARK/NEUTRAL POSITION (PNP) SWITCH CIRCUIT

If circuit or component is faulty, a Diagnostic Trouble Code (DTC) should set. Retrieve DTCs and perform appropriate diagnostic test. See SELF-DIAGNOSTICS - INTRODUCTION article.

THROTTLE POSITION (TP) SENSOR

1. Turn ignition off. Ensure throttle linkage moves smoothly. Ensure throttle lever is adjusted properly. See THROTTLE BODY LEVER ADJUSTMENT in ON-VEHICLE ADJUSTMENTS article. Disconnect electrical connector from Throttle Position (TP) sensor on throttle body. Disconnect vacuum hose from throttle body. (Scheme 61) Connect a vacuum pump to disconnected vacuum hose and apply vacuum.
2. Using ohmmeter, check resistance between specified terminals in relation to throttle position. With throttle fully closed, resistance between terminals VTA and E2 should be 200-6300 ohms. (Scheme 61) With throttle fully open, resistance between terminals VAT and E2 should be 2000-10,200 ohms. Resistance between terminals VC and E2 should be 2500-5900 ohms. If resistance is not as specified, replace TP sensor.

Scheme 61

VAPOR PRESSURE SENSOR

For vapor pressure sensor testing, see VAPOR PRESSURE SENSOR CIRCUIT under FUEL EVAPORATION SYSTEM.

VARIABLE VALVE TIMING SENSOR

Note. Variable Valve Timing (VVT) sensor may also be referred to as a Camshaft Position (CMP) sensor.

One Variable Valve Timing (VVT) sensor is mounted in outer corner of each cylinder head, just below valve cover (oil filler cap end). Remove engine cover. Disconnect VVT sensor 2-pin connector. Measure resistance between VVT sensor terminals. Resistance should be 835-1400 ohms at 14-122°F (-10-50°C), or 1060-1645 ohms at 123-212°F (51-100°C). Replace VVT sensor if resistance is not as specified.

VEHICLE SPEED SENSOR (VSS)

If a VSS circuit fault is present, a Diagnostic Trouble Code (DTC) should set. Retrieve DTCs and perform appropriate diagnostic test. See SELF-DIAGNOSTICS - INTRODUCTION article

RELAYS

Note. For cooling fan relay testing, see appropriate article in ENGINE COOLING.

Air/Fuel (A/F) HTR Relay, Circuit Opening Relay, EFI Main Relay Or Starter Relay

1. Remove relay to be tested. On RX300, circuit opening relay may be located in fuse/relay box on left side of engine compartment or relay box under left side of instrument panel. On ES300, circuit opening relay is located in fuse/relay box on left side of engine compartment. On all models, A/F HTR relay, EFI main relay and starter relay are located in the main fuse/relay box on left side of engine compartment.
2. Check for continuity between relay terminals No. 1 and 2. (Scheme 62)or (Scheme 63). Continuity should exist. Check for continuity between relay terminals No. 3 and 5. Continuity should not exist.
3. Using jumper wires, apply battery voltage across relay terminals No. 1 and 2. Check for continuity between relay terminals No. 3 and 5 with relay energized. Continuity should exist. If continuity is not as specified, replace relay.

Scheme 62

Scheme 63

See ACOUSTIC CONTROL INDUCTION SYSTEM (ACIS) under AIR INDUCTION SYSTEMS.

Canister Closed Valve Vacuum Switching Valve

See CANISTER CLOSED VALVE VACUUM SWITCHING VALVE under FUEL EVAPORATION SYSTEM.

EVAP Vacuum Switching Valve

See EVAP VACUUM SWITCHING VALVE under FUEL EVAPORATION SYSTEM.

Fuel Injectors

See FUEL CONTROL under FUEL SYSTEM.

Pressure Switching Valve Vacuum Switching Valve

See PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE under FUEL EVAPORATION SYSTEM.

Fuel Pump Resistance

Remove rear seat cushion. Remove floor service hole cover. Disconnect 5-pin connector from fuel pump and sending unit assembly. Measure resistance between 5-pin fuel pump and sending unit connector terminals No. 4 and 5. see scheme 20 Replace fuel pump if resistance is not 0.2-3.0 ohms at 68°F (20°C).

Fuel Pump Control Circuit

1. Check fuel pump operation. See «FUEL PUMP OPERATION (USING LEXUS SCAN TOOL)»(ref-2784-S07547471962000041300000) or «FUEL PUMP OPERATION (USING BATTERY VOLTAGE)»(ref-2784-S29641428112000041300000). If fuel pump does not operate, go to next step. If fuel pump operates, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-2784-S12540747322000041300000) under COMPUTERIZED ENGINE CONTROLS. Repair as necessary.
2. Check ECM power source circuit. See «ECM POWER SOURCE CIRCUIT (IGNITION KEYED)»(ref-2784-S05897813212000041300000) under COMPUTERIZED ENGINE CONTROLS. Repair as necessary. If circuit is okay, go to next step.
3. Check circuit opening relay. See «RELAYS»(ref-2784-S11786245272000041300000) under RELAYS & SOLENOIDS. Replace circuit opening relay as necessary. If relay is okay, access ECM connectors behind glove compartment. Turn ignition on. On ES300, backprobing connector, measure voltage between chassis ground and terminal No. 3 (Green/Red wire) at ECM E7 connector. (Scheme 52) On RX300, backprobing connector, measure voltage between chassis ground and terminal No. 3 (Blue/Yellow wire) at ECM E8 connector. (Scheme 53)
4. On all models, if battery voltage is not present, check for an open circuit in wiring harness between EFI main relay and circuit opening relay or between opening relay and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Replace as necessary. If battery voltage is present, go to next step.
5. Check fuel pump. See «FUEL PUMP RESISTANCE»(ref-2784-S04421473192000041300000). Replace fuel pump as necessary. If fuel pump is okay, check for an open circuit in wiring harness between circuit opening relay and fuel pump or between fuel pump and ground. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, replace ECM and retest.

Fuel Pump Pressure

To check fuel pump pressure, see FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.

Fuel Pressure Regulator

All models use a returnless fuel system and is not equipped with a fuel pressure regulator on fuel rail. Fuel pressure regulator is mounted to fuel pump assembly and is located in fuel tank. To check in tank fuel pressure regulator, perform FUEL PRESSURE test under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.

Fuel Injector Circuit

If circuit or component is faulty, a Diagnostic Trouble Code (DTC) should set. Retrieve DTCs and perform appropriate diagnostic test. See SELF-DIAGNOSTICS - INTRODUCTION article.

Fuel Injector Resistance

Remove engine cover. Turn ignition off. Disconnect appropriate injector connector. Measure resistance between injector terminals. Resistance should be about 13.4-14.2 ohms at 68°F (20°C). If resistance is not about 13.4-14.2 ohms at 68°F (20°C), replace injector.

Scheme 64

Scheme 65

Scheme 66

1. Remove fuel injector. See FUEL SYSTEM under REMOVAL, OVERHAUL & INSTALLATION article. Fuel injector is connected to fuel filter for checking fuel injector volume. Remove fuel pipe clamp from No. 1 fuel pipe at fuel filter. Perform STEP 1. (Scheme 64) Ensure area around No. 1 fuel pipe and fuel filter is clean. Depress both sides of retainer and pull No. 1 fuel pipe with disconnect fitting from fuel filter. Perform STEP 2. (Scheme 64)
2. Purchase a NEW No. 1 fuel pipe Part No. (23801-20060) from parts department. No. 1 fuel pipe is the fuel pipe that attaches to top of fuel filter. Remove fuel pipe connector from end of NEW No. 1 fuel pipe. (Scheme 65)
3. Install delivery hose from Fuel Injector Measuring Kit (SST 09268-41047) with fuel pipe connector on fuel filter. (Scheme 65) Ensure delivery hose and fuel pipe connector are properly connected on fuel filter. Check that grommet and "O" ring are installed on top of fuel injector. Using clamp and union from fuel injector measuring kit, connect fuel injector to delivery hose. (Scheme 65)
4. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage. Connect scan tool to Data Link Connector (DLC) No. 3. see scheme 8or see scheme 9. Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: Fuel pump may also be operated to pressurize fuel system by applying battery voltage to fuel pump connector terminals. For operating of fuel pump, see «FUEL PUMP OPERATION (USING BATTERY VOLTAGE)»(ref-2784-S29641428112000041300000) under FUEL DELIVERY.
5. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 66) 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-2784-S01251960672000041300000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-2784-S01251960672000041300000) table.
6. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop within 12 minutes. Replace fuel injector if leakage exceeds specification. Disconnect negative battery cable. Remove test equipment. Apply light coat of engine oil on tip of pipe on fuel filter to allow for ease of disconnect fitting and No. 1 fuel pipe installation. CAUTION: DO NOT reuse old retainer when installing No. 1 fuel pipe on fuel filter. Always use a NEW retainer.
7. Using NEW retainer, install No. 1 fuel pipe on fuel filter until "click" sound is head. DO NOT reuse old retainer. Pull on No. 1 fuel pipe to ensure fuel pipe connector is properly locked on fuel filter.
8. Reinstall fuel pipe clamp until "click" sound is head. Pull upward on fuel pipe clamp to ensure clamp is securely locked on fuel filter. Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

FUEL INJECTOR VOLUME SPECIFICATIONS

Scheme 67

Scheme 68

1. Remove fuel injector. See FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Fuel injector is connected to fuel inlet pipe for checking fuel injector volume. Remove fuel pipe clamp from No. 1 fuel pipe at fuel inlet pipe. Perform STEP 1. (Scheme 67) Ensure area around No. 1 fuel pipe and fuel inlet pipe is clean. Depress both sides of retainer and pull No. 1 fuel pipe with disconnect fitting from fuel inlet pipe. Perform STEP 2. (Scheme 67)
2. Purchase a NEW No. 1 fuel pipe Part No. (23801-20040) from parts department. Remove fuel pipe connector from end of NEW No. 1 fuel pipe. (Scheme 68)
3. Install delivery hose from Fuel Injector Measuring Kit (SST 09268-41047) with fuel pipe connector on fuel inlet pipe. (Scheme 68) Ensure delivery hose and fuel pipe connector are properly connected on fuel inlet pipe. Check that grommet and "O" ring are installed on top of fuel injector. Using clamp and union from fuel injector measuring kit, connect fuel injector to delivery hose. (Scheme 68)
4. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage. Connect scan tool to data link connector No. 3. see scheme 8or see scheme 9. Turn ignition on. Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. NOTE: Fuel pump may also be operated to pressurize fuel system by applying battery voltage to fuel pump connector terminals. For operating of fuel pump, see «FUEL PUMP OPERATION (USING BATTERY VOLTAGE)»(ref-2784-S29641428112000041300000) under FUEL DELIVERY.
5. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 66) 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-2784-S01251960672000041300000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. See «FUEL INJECTOR VOLUME SPECIFICATIONS»(ref-2784-S01251960672000041300000) table.
6. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop per minute. Replace fuel injector if leakage exceeds specification. Disconnect negative battery cable. Remove test equipment. Apply light coat of engine oil on tip of fuel inlet pipe to allow for ease of disconnect fitting and No. 1 fuel pipe installation. CAUTION: DO NOT reuse old retainer when installing No. 1 fuel pipe on fuel inlet pipe. Always use a NEW retainer.
7. Using NEW retainer, install No. 1 fuel pipe on fuel inlet line until "click" sound is head. DO NOT reuse old retainer. Pull on No. 1 fuel pipe to ensure fuel pipe connector is properly locked on fuel inlet pipe.
8. Reinstall fuel pipe clamp until "click" sound is head. Pull upward on fuel pipe clamp to ensure clamp is securely locked on fuel inlet pipe. Install negative battery cable. Check for fuel leaks by using scan tool to energize fuel pump.

AIR ASSIST SYSTEM

1. Ensure engine is at normal operating temperature. Ensure idle speed is 650-750 RPM. Ensure transmission is in Neutral. Turn A/C off. Connect Jumper Wire (09843-18020) between terminals TE1 and E1 of DLC No. 1. see scheme 26 On ES300, DLC No. 1 is located on front of air intake chamber. On RX300, DLC No. 1 is located on left side of engine compartment, behind fuse box.
2. On all models, engine speed should increase to about 900-1300 RPM for about 10 seconds then return to idle (650-750 RPM). Turn ignition off. Disconnect air assist hose from air pipe. (Scheme 69) Plug hose end, and cap off hose pipe fitting.
3. Start engine. If engine idles at about 500 RPM or less (or if engine stalls), air assist system is okay. If engine speed does not operate as specified, check and repair vacuum leak.

Scheme 69

IGNITION SYSTEM

Note. For basic ignition checks, see IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES article.

EMISSION SYSTEMS & SUB-SYSTEMS

Scheme 70

Scheme 71

FUEL EVAPORATION SYSTEM

Note. Fuel EVAP system may also referred to as On-Board Refilling Vapor Recovery (ORVR) system.

Scheme 72

Scheme 73

Scheme 74

Scheme 75

1. Fuel EVAP system is also referred to as On-Board Refilling Vapor Recovery (ORVR) system. Inspect all EVAP system lines and connections for sharp bends or damage. (Scheme 70)or (Scheme 71). 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 (under air filter housing), in the purge vacuum hose for EVAP system. (Scheme 70)or (Scheme 71).
3. EVAP Vacuum Switching Valve (VSV) must be operated. 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 (DLC) No. 3. see scheme 8or see scheme 9. 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 EVAP VSV connector. EVAP VSV is mounted on air intake chamber and contains a Blue 2-pin electrical connector. (Scheme 50) Using jumper wires, connect battery voltage and ground to EVAP VSV terminals. Start engine. Go to next step.
6. Check vacuum reading on vacuum gauge with engine idling. Vacuum should be.368-19.713 in. Hg for more than 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-2784-S22488750242000041300000).
7. Shut engine off. If using scan tool to operate 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. Locate charcoal canister under rear of vehicle near fuel tank. (Scheme 72)or (Scheme 73). Install hose crimper on charcoal canister air drain hose. Air hose may be marked with a Yellow line indicating area to be crimped at.
9. Apply 13.5-15.5 in. H 2 O of pressure to EVAP service port. After 2 minutes of applying the pressure, the pressure should be 7.7-8.8 in. H 2 O. If pressure is within specification, remove hose crimper and go to next step. If pressure cannot be maintained, remove hose crimper and 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-2784-S22488750242000041300000).
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. (Scheme 72)or (Scheme 73). Apply.58 psi (.040 kg/cm 2 ) air pressure to EVAP line hose so pressure inside the 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 tank 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. NOTE: Overfill check valve may also be referred to as fill check valve. Cut-off valve may also be referred to as fuel cut-off valve.
13. To check overfill check valve and cut-off valve, disconnect purge line hose, air drain hose aND EVAP line hose from charcoal canister. Install cap on air drain hose port. (Scheme 72)or (Scheme 73).
14. Apply.58 psi (.040 kg/cm 2 ) air pressure to purge line hose fitting on charcoal canister. (Scheme 72)or (Scheme 73). 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 72)or (Scheme 73).
16. Reinstall purge line hose, air drain hose and EVAP line hose on charcoal canister. To check air inlet line, disconnect air inlet line hose from charcoal canister. (Scheme 72)or (Scheme 73). 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. 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.
18. 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 74)
19. Remove charcoal canister and vapor pressure sensor retaining bolts. 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, install cap on vent port on charcoal canister. (Scheme 75) Apply.26 psi (.018 kg/cm 2 ) air pressure to EVAP port while holding purge port closed. 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 75) Ensure no air flows from air inlet port.
22. Using vacuum pump, apply 1.01 in. Hg of vacuum to purge port. (Scheme 75) 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 75) Ensure air flows into purge port. Remove 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), vapor pressure sensor, pressure switching valve and canister closed valve VSV. See «EVAP VACUUM SWITCHING VALVE»(ref-2784-S22488750242000041300000), «VAPOR PRESSURE SENSOR CIRCUIT»(ref-2784-S08357442322000041300000), «PRESSURE SWITCHING VALVE VACUUM SWITCHING VALVE»(ref-2784-S18687636342000041300000) and «CANISTER CLOSED VALVE VACUUM SWITCHING VALVE»(ref-2784-S40726105292000041300000).

Charcoal Canister

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

1. Remove engine cover. Remove control valve set and wire harness cover. (Scheme 50) Disconnect electrical connector and vacuum hoses from EVAP Vacuum Switching Valve (VSV). Measure resistance between VSV terminals. If resistance is 27-33 ohms at 68°F (20°C), go to next step. If resistance is not as specified, replace VSV.
2. Check for continuity between VSV case and each terminal of VSV connector (this checks for an internal short). If continuity does not exist, go to next step. If continuity exists, replace VSV.
3. Apply compressed air to port "E". (Scheme 76) Air should not flow from port "F". If VSV function as specified, go to next step. If VSV does not function as specified, replace VSV.
4. Apply battery voltage across VSV terminals. Apply compressed air to port "E". If air flows out of port "F", VSV is functioning properly. If air does not flow out of port "F", replace VSV.

Scheme 76

Vapor Pressure Sensor Circuit

Note. Vapor pressure sensor is available is 2 different configurations. Type "A" sensor has one vacuum port on each side of sensor. (Scheme 78) Type "B" sensor has 2 vacuum ports on the same side of sensor.

1. Disconnect vapor pressure sensor connector. Sensor has 2 vacuum ports and is mounted on top of EVAP charcoal canister underneath rear of vehicle. (Scheme 72)or (Scheme 73). Turn ignition on. Measure voltage between terminals VC and E2 at vapor pressure sensor connector terminals. (Scheme 77) If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, check wiring harness between sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, replace ECM.
2. Turn ignition off. Reconnect vapor pressure sensor connector. Access ECM harness connectors behind glove box. Disconnect vapor pressure sensor vacuum hose. (Scheme 78) Turn ignition on.
3. On ES300, backprobing ECM harness connector, measure voltage between terminals No. 18 (Brown wire) at ECM E10 connector and No. 17 (Pink wire) at ECM E7 connector. (Scheme 52) On RX300, backprobing ECM harness connector, measure voltage between terminals No. 18 (Brown wire) at ECM E6 connector and No. 17 (Blue/Orange wire) at ECM E8 connector. (Scheme 53) On all models, voltage reading should be as follows: 3.0-3.6 volts with no vacuum applied. 1.3-2.1 volts with.59 in. Hg (2.0 kPa) of vacuum applied. 4.2-4.8 volts with.22 psi (1.5 kPa) of pressure applied. If voltage is not as specified, replace vapor pressure sensor.

Scheme 77

Scheme 78

1. Remove pressure switching valve Vacuum Switching Valve (VSV). VSV has 2 vacuum ports, a Blue 2-pin connector and is mounted on top of EVAP canister. (Scheme 72)or (Scheme 73). Measure resistance between pressure switching valve VSV terminals. If resistance is 37-44 ohms at 68°F (20°C), go to next step. If resistance is not 37-44 ohms, replace VSV.
2. Check for continuity between pressure switching valve VSV case and each terminal of VSV connector (this checks for an internal short). If continuity does not exist, go to next step. If continuity exists, replace pressure switching valve VSV.
3. Apply air pressure to VSV port "E". (Scheme 79) If air does not flow from port "F", go to next step. If air flows from port "F", replace VSV.
4. Using jumper wires, apply battery voltage and ground across VSV terminals. Apply compressed air to port "E". If air flows out of port "F", VSV is functioning properly. If air does not flow from port "F", replace VSV.

Scheme 79

1. Remove canister closed valve Vacuum Switching Valve (VSV). VSV has 2 vacuum ports, a Black 2-pin connector and is located on or near air filter housing. (Scheme 72)or (Scheme 73). Measure resistance between canister closed valve VSV terminals. If resistance is 25-30 ohms at 68°F (20°C), go to next step. If resistance is not 25-30 ohms, replace VSV.
2. Check for continuity between canister closed valve VSV case and each terminal of VSV connector (this checks for an internal short). If continuity does not exist, go to next step. If continuity exists, replace canister closed valve VSV.
3. Apply air pressure to VSV port "A". (Scheme 80) If air flows from port "B", go to next step. If air does not flow from port "B", replace VSV.
4. Using jumper wires, apply battery voltage and ground across VSV terminals. Apply compressed air to port "A". If air does not flow out of port "B", VSV is functioning properly. If air flows from port "B", replace VSV.

Scheme 80

PCV Valve

Remove PCV valve from valve cover. Inspect PCV hoses, connections and gaskets for leaks and damage. Apply compressed air to cylinder head side of PCV valve. Air should pass freely through PCV valve. Apply compressed air to intake manifold side of PCV valve. Air should not pass freely through PCV valve. Clean or replace PCV valve if air does not flow as specified.

CAMSHAFT TIMING OIL CONTROL VALVE

Note. Camshaft timing oil control valve is also referred to as oil control valve.

Resistance Check

Remove engine cover. Disconnect connector from Oil Control Valve (OCV) to be tested. Oil control valves are located at front top of each cylinder head. On ES300, left OCV has a 2-pin connector with Green/Yellow and Green/Red wires. Right OCV has a 2-pin connector with Green/White and Green wires. On RX300, left OCV has a 2-pin connector with Green/Yellow and Green/Red wires. Right OCV has a 2-pin connector with Green/White and Yellow/Black wires. On all models, measure resistance between OCV terminals. Resistance should be 6.9-7.9 ohms at 68°F (20°C). If resistance is not 6.9-7.9 ohms, replace OCV.

VARIABLE VALVE TIMING (VVT) SENSOR

For VVT sensor testing, see VARIABLE VALVE TIMING SENSOR under ENGINE SENSORS & SWITCHES.

THROTTLE OPENER

Note. Throttle opener testing for RX300 is not available from manufacturer.

1. Start engine and warm engine to normal operating temperature. Ensure idle speed is 650-750 RPM. Disconnect and plug vacuum hose at throttle opener near throttle body. (Scheme 81)
2. Start engine and note engine speed. Engine speed should be 1100-1700 RPM. If engine speed is not 1100-1700 RPM, replace throttle body. See THROTTLE BODY under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article.

Scheme 81

MISCELLANEOUS CONTROLS

Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.

COOLING FAN SYSTEM

For electric cooling fan testing, see SPECIFICATIONS & ELECTRIC COOLING FANS article in ENGINE COOLING.

TRANSMISSION

For transmission diagnostic information, see appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS.