Engine Controls - System & Component Testing: Other Lexus ES XV30 facelift

Intake Air Control System (ES300)

1. Using 3-way connector, connect vacuum gauge to actuator hose. (Scheme 205) Connect hand-held tester to DLC3. see scheme 15 Start engine. Select ACTIVE TEST mode according to message on hand-held tester. With VSV on, vacuum should be about 7.9 in. Hg (27 kPa). With VSV off, no vacuum should be present.
2. Shift transmission into Park and operate accelerator pedal. Check data monitor operation. (Scheme 206) Valve shown in illustration is for reference only, throttle valve may operate differently depending on running condition. If operation is not to specification, check intake air control valve assemblies.

Scheme 205

Scheme 206

Intake Air Control Valve (RX300)

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 207) No 2 IACV is located on front of air intake chamber. (Scheme 208) 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 207)or (Scheme 208).
2. Snap accelerator to Wide Open Throttle (WOT). Ensure vacuum reading momentarily reads about 7.9 in. Hg (27 kPA) 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»(ref-151794-S18055444492003010800000) in REMOVAL & INSTALLATION - EXCEPT GX470 article. Apply about 7.9 in. Hg (27 kPA) 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-151786-S35238701812003010800000).

Scheme 207

Scheme 208

ACIS Vacuum Tank

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 209) Apply air pressure to port "A". Ensure air does not flow from port "B". Perform STEP 2. (Scheme 209) Go to next step.
2. Plug port "B" on vacuum tank. Using vacuum pump, apply 7.9 in. Hg (27 kPA) of vacuum to port "A". Perform STEP 3. (Scheme 209) 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-151786-S21280692312003010800000).

Scheme 209

ACIS Vacuum Switching Valve

1. Remove engine cover and wire harness cover. Remove emission control valve set. (Scheme 210) 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 211) 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 210

Scheme 211

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 appropriate SELF-DIAGNOSTICS article.

ECM POWER SOURCE CIRCUIT (IGNITION ON)

Note. For information on engine immobilizer, see THEORY & OPERATION article.

STARTER SIGNAL CIRCUIT

Note. For information on engine immobilizer, see THEORY & OPERATION article.

AIR/FUEL (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 212) 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 212

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 (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-151786-S24410589802003010800000) 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 213) 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 213

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. Air/Fuel sensor refers to sensor closest to engine block. See AIR/FUEL (A/F) SENSOR HEATER RESISTANCE . Heated oxygen sensor refers to sensor furthest away from engine block, behind catalytic converter.

On RX300, bank No. 1 sensor connector is located under driver's seat carpet, next to center counsel. Remove driver's seat to access connector. On all models, disconnect oxygen sensor connector. Measure resistance between terminals B+ and HT at oxygen sensor connector. (Scheme 212) Replace oxygen sensor if resistance is not 11.0-16.0 ohms at 68°F (20°C) or 23-32 ohms at 1472°F (800°C).

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 214) Replace MAF sensor if resistance is not as specified. See INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE table.

INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE

Scheme 214

KNOCK SENSOR

Remove knock sensor. See KNOCK SENSOR under SENSORS & SWITCHES in REMOVAL & INSTALLATION - EXCEPT GX470 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 214) 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 215) Apply compressed air to MAF sensor. If voltage does not fluctuate while applying compressed air to MAF sensor, replace MAF sensor.

Scheme 215

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»(ref-151794-S03812214932003010800000) under SENSORS & SWITCHES in REMOVAL & INSTALLATION - EXCEPT GX470 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-151786-S42262195452003010800000) table. (Scheme 216) If continuity is not as specified, replace PNP switch. If continuity is as specified, install and adjust PNP switch.

PNP SWITCH CONTINUITY

Scheme 216

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 appropriate SELF-DIAGNOSTICS article.

ES300

Disconnect throttle position sensor connector. Measure resistance between terminals VC and E2. Resistance should be 1.2-3.2 k/ohms. (Scheme 217) If resistance is not as specified, replace TP sensor.

Scheme 217

RX300

1. Turn ignition off. Ensure throttle linkage moves smoothly. Ensure throttle lever is adjusted properly. See «THROTTLE BODY LEVER ADJUSTMENT»(ref-151768-S32446555052003010800000) in ON-VEHICLE ADJUSTMENTS article. Disconnect electrical connector from Throttle Position (TP) sensor on throttle body. Disconnect vacuum hose from throttle body. (Scheme 218) 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 218) With throttle fully open, resistance between terminals VTA 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 218

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.

For Variable Valve Timing (VVT) sensor testing on ES300, see SELF-DIAGNOSTICS - ES300 article. For VVT sensor testing on RX300, see SELF-DIAGNOSTICS - RX300 article.

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 appropriate SELF-DIAGNOSTICS article.

RELAYS

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

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 SYSTEMS

Note. For information on engine immobilizer, see THEORY & OPERATION article.

FUEL SYSTEM PRESSURE RELEASE

For procedure, see FUEL SYSTEM in REMOVAL & INSTALLATION - EXCEPT GX470 article.

Fuel Pump Resistance

On ES300, measure resistance between fuel pump 2-pin terminals. On RX300, measure resistance between 5-pin fuel pump terminals No. 4 and 5. (Scheme 219)and (Scheme 220). Replace fuel pump if resistance is not 0.2-3.0 ohms at 68°F (20°C).

Scheme 219

Scheme 220

Fuel Pump Control Circuit (RX300)

1. Check fuel pump operation. See «FUEL SYSTEM»(ref-151770-S15165288182003010800000) under BASIC DIAGNOSTIC PROCEDURES. If fuel pump does not operate, go to next step. If fuel pump operates, check starter signal circuit. See «STARTER SIGNAL CIRCUIT»(ref-151786-S04450269282003010800000) under COMPUTERIZED ENGINE CONTROLS. Repair as necessary.
2. Check ECM power source circuit. See «ECM POWER SOURCE CIRCUIT (IGNITION ON)»(ref-151786-S33355709672003010800000) under COMPUTERIZED ENGINE CONTROLS. Repair as necessary. If circuit is okay, go to next step.
3. Check circuit opening relay. See «RELAYS»(ref-151786-S31514697312003010800000) 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. 10 (Green/Red wire) at ECM E6 connector. see scheme 13 On RX300, backprobing connector, measure voltage between chassis ground and terminal No. 3 (Blue/Yellow wire) at ECM E5 connector. see scheme 14
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 ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Replace as necessary. If battery voltage is present, go to next step.
5. Check fuel pump. See «FUEL PUMP RESISTANCE»(ref-151786-S11634784362003010800000). 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 ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary. If wiring is okay, replace ECM and retest.

Fuel Pump Pressure

To check fuel pump pressure, perform fuel pressure test under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.

Fuel Pressure Regulator

To 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 appropriate SELF-DIAGNOSTICS 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.

Fuel Injector Volume (ES300)

1. Remove fuel injector. See «FUEL SYSTEM»(ref-151794-S09024588512003010800000) under REMOVAL & INSTALLATION - GX470 article. Purchase new No. 1 Fuel Pipe (23801-20150) and take out fuel tube connector from its pipe. (Scheme 221) Connect hose and fuel tube connector to fuel pipe. (Scheme 222) Install grommet and "O" ring to injector. Connect union and hose to injector. Hold injector and union with clamp. (Scheme 223)
2. 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 15 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. (Scheme 219)and (Scheme 220). See «FUEL SYSTEM»(ref-151770-S15165288182003010800000) in BASIC DIAGNOSTIC PROCEDURES article.
3. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. (Scheme 224) 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-151786-S07771273542003010800000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification. Disconnect voltage from fuel injector. Check fuel leakage from injector. Leakage should be one drop or less per 12 minutes. FUEL INJECTOR VOLUME SPECIFICATIONS Application (1) Cu. In. (cc) Volume 3.7-4.5 (60-73) Difference Between Injectors 0.8 (13) (1) Specification listed is for a 15 second period.

Scheme 221

Scheme 222

Scheme 223

Scheme 224

Fuel Injector Volume (RX300)

1. Disconnect negative battery cable. Remove fuel injector. See «FUEL SYSTEM»(ref-151794-S09024588512003010800000) in REMOVAL & INSTALLATION - GX470 article. Purchase new No. 1 Fuel Pipe (23801-20120) and take out fuel tube connector from its pipe. (Scheme 221)
2. Remove fuel hose clamp. Disconnect No. 1 fuel pipe (fuel tube connector) from fuel inlet pipe. If there is retained fuel pressure, prevent fuel splash inside engine compartment. (Scheme 225) Install Pressure Gauge and fuel tube connector. Wipe off any splattered gasoline. Reconnect negative battery cable.
3. Install delivery hose from Fuel Injector Measuring Kit (SST 09268-41047) with fuel pipe connector on fuel inlet pipe. (Scheme 226) 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 226)
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 16 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 SYSTEM»(ref-151770-S15165288182003010800000) in BASIC DIAGNOSTIC PROCEDURES article.
5. Connect Fuel Injector Tester (09842-30070) to fuel injector for 15 seconds. 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-151786-S07771273542003010800000) table. Ensure difference between fuel injector volume on all fuel injectors is within specification.
6. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector does not exceed one drop every 12 minutes. Replace fuel injector if leakage exceeds specification. 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 heard. 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 heard. 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.

Scheme 225

Scheme 226

AIR ASSIST SYSTEM

1. Ensure engine is at normal operating temperature. Ensure idle speed is 650-750 RPM, transmission is in Neutral and A/C is off. Connect Jumper Wire (09843-18020) between terminals TE1 and E1 of DLC No. 1. see scheme 34 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 227) 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 227

IGNITION SYSTEM

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

EMISSION SYSTEMS & SUB-SYSTEMS

Note. For information on engine immobilizer, see THEORY & OPERATION article.

Scheme 228

Scheme 229

FUEL EVAPORATION SYSTEM

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

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 210) 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 230) Air should not flow from port "F". If VSV functions 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 230

Vapor Pressure Sensor Circuit (ES300)

Note. ES300 vapor pressure sensor is available in 2 different configurations. Type "A" sensor has one vacuum port on each side of sensor. (Scheme 232) Type "B" sensor has 2 vacuum ports on the same side of sensor.

1. Disconnect vapor pressure sensor electrical connector. Sensor has 2 vacuum ports and is mounted on charcoal canister underneath rear of vehicle. see scheme 39 Turn ignition on. Measure voltage between terminals VC and E2 at vapor pressure sensor connector terminals. (Scheme 231) 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 ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. 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. Connect vacuum/pressure pump to sensor port. (Scheme 232) Turn ignition on.
3. Backprobing ECM harness connector, measure voltage between terminal No. 18 (Brown wire) at ECM E10 connector terminal and No. 17 (Pink wire) at ECM E7 connector. see scheme 13 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 231

Scheme 232

Vapor Pressure Sensor Circuit (RX300)

1. Disconnect vapor pressure sensor electrical connector. Sensor is mounted on top of fuel tank. (Scheme 233) Manufacturer recommends lowering fuel tank to gain access to vapor pressure sensor. Turn ignition on. Measure voltage between terminals VC and E2 at vapor pressure sensor connector terminals. (Scheme 234) 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 ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. 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. Connect vacuum/pressure pump to vapor pressure sensor. (Scheme 234) Turn ignition on.
3. Backprobing ECM harness connector, measure voltage between terminal No. 18 (Brown wire) at ECM E8 connector terminal and No. 17 (Blue/Orange wire) at ECM E5 connector. see scheme 14 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 233

Scheme 234

1. Remove pressure switching valve Vacuum Switching Valve (VSV). VSV has 2 vacuum ports, a Blue 2-pin connector and is mounted on vapor canister. see scheme 39or see scheme 40. Measure resistance between pressure switching valve VSV terminals. If resistance is 37-44 ohms at 68°F (20°C) or 51-62 ohms at 248°F (120°C), go to next step. If resistance is not as specified, 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 235) 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 235

1. Remove canister closed valve Vacuum Switching Valve (VSV). VSV has 2 vacuum ports, a Black 2-pin connector and is located on air filter housing. (Scheme 228)and (Scheme 229). Measure resistance between canister closed valve VSV terminals. If resistance is 25-30 ohms at 68°F (20°C) or 33-42 ohms at 248°F (120°C), go to next step. If resistance is not as specified, 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 large port. If air flows from small port, go to next step. If air does not flow from small port, replace VSV.
4. Using jumper wires, apply battery voltage and ground across VSV terminals. Apply compressed air to large port. If air does not flow out of small port, VSV is functioning properly. If air flows from small port, replace VSV.

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

1. 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.
2. 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 SENSORS & SWITCHES.

THROTTLE OPENER

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

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 236) 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 & INSTALLATION - EXCEPT GX470 article.

Scheme 236

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 appropriate ELECTRIC COOLING FANS article in ENGINE COOLING.

TRANSMISSION

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