36 ENGINE — 1NZ-FE ENGINEJENGINE CONTROL SYSTEM 1. General The engine control system for the 1NZ-FE engine has following system. System Outline SFI D An L-type SFI system directly detects the intake air volume with a hot-wire Sequential Multiport type mass air flow meter. Fuel Injection D The fuel injection system is a sequential multiport fuel injection system. D Ignition timing is determined by the ECM based on signals from various ESA sensors. The ECM corrects ignition timing in response to engine knocking. Electronic Spark Advance D In vehicles equipped with automatic transaxle, torque control correction during gear shifting has been used to minimize the shift shock. IAC (Idle Air Control) A rotary solenoid type IAC valve controls the fast idle and idle speeds. VVT-i Controls the intake camshaft to an optimal valve timing in accordance with the Variable Valve engine condition. Timing-intelligent Fuel Pump Control Fuel pump operation is controlled by signal from the ECM. Oxygen Sensor Heater Maintains the temperature of the oxygen sensors at an appropriate level to in- Control crease accuracy of detection of the oxygen concentration in the exhaust gas. Evaporative Emission The ECM controls the purge flow of evaporative emissions (HC) in the char- Control coal canister in accordance with engine conditions. Air Conditioning By turning the air conditioning compressor OFF in accordance with the engine Cut-Off Control condition, drivability is maintained. Radiator cooling fan operation is controlled by signals from ECM based on the Cooling Fan Control engine coolant temperature sensor signal (THW). When the ECM detects a malfunction, the ECM diagnoses and memorizes Diagnosis the failed section. When the ECM detects a malfunction, the ECM stops or controls the engine Fail-Safe according to the data already stored in memory. 2000 ECHO (NCF 171U) SENSOR OCV STA IGNITION SWITCH ECM • Starting Signal (ST Terminal) SPD RSD COMBINATION METER • Vehicle Speed Signal OX1A HEATED OXYGEN SENSOR (Bank 1. 2 INJECTOR 2000 ECHO (NCF 171U) . ENGINE — 1NZ-FE ENGINE 37 2. SENSOR THA INTAKE AIR TEMP. Construction The configuration of the engine control system in the 1NZ-FE engine is shown in the following chart. Sensor FC 1) OX1B HEATED OXYGEN SENSOR (Bank 1. 1 INJECTOR (Continued) No. SENSORS VG MASS AIR FLOW METER #10 #20 NE CRANKSHAFT POSITION #30 SENSOR #40 G2 CAMSHAFT POSITION SENSOR IGT1~ IGT4 VTA THROTTLE POSITION SENSOR IGF THW ENGINE COOLANT TEMP. Sensor 2) KNK1 KNOCK SENSOR HT PSP OIL*1 POWER STEERINGHT2 PRESSURE SWITCH ACTUATORS SFI No. 3 INJECTOR No. Sensor 2 2000 ECHO (NCF 171U) . 4 INJECTOR ESA IGNITION COIL with IGNITER SPARK PLUGS VVT-i CAMSHAFT TIMING OIL CONTROL VALVE IAC CONTROL VALVE FUEL PUMP CONTROL CIRCUIT OPENING RELAY OXYGEN SENSOR HEATER CONTROL HEATED OXYGEN SENSOR HEATER Bank 1.38 No. Sensor 1 Bank 1. ENGINE — 1NZ-FE ENGINE 39 AC CONDITIONING AIR AMPLIFIER*2 ACT PARK/NEUTRAL POSITION NSW SWITCH*3 • Neutral Start Signal R.D.2. SIL COOL DATA TCLINK CONNECTOR 3 W ALT GENERATOR AIR CONDITIONING CUT-OFF CONTROL*2 +B BATT AIR CONDITIONING AMPLIFIER EFI MAIN RELAY BATTERY EVAP CONTROL *1: with Power Steering *2: with Air Conditioning VSV (for EVAP) *3: Only for Automatic Transaxle Model VSV (for CANISTER CLOSED VALVE) COOLING FAN CONTROL COOLING FAN RELAY ENGINE COOLANT TEMP. INDICATORS 2000 ECHO (NCF 171U) .L • Shift Lever Position Signal EVP1 CCV PTNK ECM VAPOR PRESSURE SENSOR STP CF STOP LIGHT SWITCH HOT. 40 MALFUNCTION INDICATOR LAMP 2000 ECHO (NCF 171U) . Sensor 1) *1: with Air Conditioning *2: Only for Automatic Transaxle Model *3: with Power Steering 171EG28 2000 ECHO (NCF 171U) . Sensor) IAC Valve VSV (for EVAP) Injector Igniter Camshaft Position VSV (for Canister Sensor Closed Valve) Engine Coolant Charcoal Camshaft Timing Temp. Sensor 2) Heated Oxygen Sensor (Bank 1. Oil Control Valve Sensor Canister Fuel Knock Crankshaft Pump Sensor Position Sensor Vapor TWC Pressure Sensor Heated Oxygen Sensor (Bank 1. Engine Control System Diagram Park/Neutral Position Malfunction Switch*2 Indicator Lamp DLC3 Ignition Generator Switch Meter (Vehicle Speed Signal) A/C Amplifier*1 or A/C Switch*1 ECM Power Steering Oil Pressure Sensor*3 Electric Load Switch Throttle Position Sensor Mass Air Flow Meter Battery Circuit (Built-in Intake Air Opening Relay Temp. ENGINE — 1NZ-FE ENGINE 41 3. Layout of Components Camshaft Position Sensor Camshaft Timing Oil Control Valve 2000 ECHO (NCF 171U) Knock Sensor ENGINE — 1NZ-FE ENGINE Vapor Pressure Sensor Crankshaft DLC3 Position Sensor Throttle Heated Oxygen Sensor Position Sensor (Bank 1. Sensor 1) Water Temperature Sensor 171EG39 . Sensor 2) IAC Valve Heated Oxygen Sensor (Bank 1. 42 VSV (for EVAP) VSV Mass Air ECM (for Canister Closed Valve) Flow Meter 4. VVT-i (Variable Valve Timing-intelligent) System General The VVT-i system is designed to control the intake camshaft within a wide range of 60° (of crankshaft angle) to provide a valve timing that is optimally suited to the engine condition. and reduce exhaust emissions. Main Components of Engine Control System The main components of the 1NZ-FE engine control system are as follows: Components Outline Quantity Mass Air Flow Meter Hot-Wire Type 1 Crankshaft Position Sensor (Rotor’s Teeth) Pick-Up Coil Type (36-2) 1 Camshaft Position Sensor (Rotor’s Teeth) Pick-Up Coil Type (3) 1 Throttle Position Sensor Linear Type 1 Knock Sensor Built-In Piezoelectric Element Type 1 Heated Oxygen Sensor Oxygen Sensor (Bank 1. Sensor 1) 2 (Bank 1. thus realizing improved torque in all the speed ranges and fuel economy. VVT-i Controller ECM Camshaft Position Sensor Crankshaft Position Sensor Camshaft Timing Oil Control Valve 171EG30 2000 ECHO (NCF 171U) . Sensor 2) Injector 12-Hole Type 4 Rotary Solenoid Type IAC Valve (1-Coil Type) 1 6. ENGINE — 1NZ-FE ENGINE 43 5. the intake camshaft will be in the most retarded state to ensure startability. Spring Drain Drain Plunger Oil Coil Pressure 165EG34 2000 ECHO (NCF 171U) . When the engine is stopped. the camshaft timing oil control valve is in the most retarded state. Vane Lock Pin (Fixed on Intake Camshaft) Intake Camshaft 171EG31 Housing Oil Pressure At a Stop In Operation Lock Pin 169EG36 2) Camshaft Timing Oil Control Valve The camshaft timing oil control valve controls the To VVT-i Controller spool valve position in accordance with the duty (Advanced Side)(Retard Side) control from the ECM thus allocating the hydrau.Sleeve Spool Valve lic pressure that is applied to the VVT-i controller to the advance and the retard side. The oil pressure sent from the advance or retard side path at the intake camshaft causes rotation in the VVT-i controller vane circumferential direction to vary the intake valve timing continuously. When hydraulic pressure is not applied to the VVT-i controller immediately after the engine has been started.44 ENGINE — 1NZ-FE ENGINE Construction 1) VVT-i Controller This controller consists of the housing driven from the timing chain and the vane coupled with the intake camshaft. When the en- gine is stopped. the lock up pin locks the movement of the VVT-i controller to prevent a knocking noise. the result- Direction ant oil pressure is applied to the ECM timing advance side vane cham- ber to rotate the camshaft in the Duty Ratio timing advance direction. After setting at the target timing. 2000 ECHO (NCF 171U) . the resultant Direction ECM oil pressure is applied to the tim- ing retard side vane chamber to rotate the camshaft in the timing Duty Ratio retard direction. ENGINE — 1NZ-FE ENGINE 45 Operation The camshaft timing oil control valve selects the path to the VVT-i controller according to the advance. the valve timing is held by keeping Hold ECM the camshaft timing oil control valve in the neutral position un- less the traveling state changes. retard or hold signal from the ECM. Oil Pressure 157EG35 171EG36 Retard Signal When the camshaft timing oil control valve is positioned as il- lustrated at left by the retard sig- Retard Rotating nal from the ECM. The VVT-i controller rotates the intake camshaft in the timing advance or retard position or holds it according to the position where the oil pressure is applied. Oil Pressure 157EG36 171EG37 Hold Signal The ECM calculates the target timing angle according to the traveling state to perform con- trol as described above. This adjusts the valve timing at Duty Ratio the desired target position and Oil Pressure prevents the engine oil from 157EG37 running out when it is unneces- 171EG38 sary. Camshaft Timing Oil Operation Control Valve Drive Description Signal Vane Advance Signal (Fixed on intake camshaft) When the camshaft timing oil VVT-i control valve is positioned as il- Controller lustrated at left by the advance Advance Rotating Housing signal from the ECM. Stabilized fast At low temperatures — EX Latest timing crease at low temperatures. " Operation During Various Driving Condition (Conceptual Diagram) A Full Load Performance Range 5 Engine Load Range 4 Range 3 Range 2 Range 1 Engine Speed 165EG38 Operation Range Valve Timing Objective Effect State TDC Stabilized IN Eliminating overlap to reduce idling rpm During idling 1 EX Latest timing blow back to the intake side Better fuel economy IN Decreasing overlap to elimi.46 ENGINE — 1NZ-FE ENGINE In proportion to the engine speed. Ensured At light load 2 EX To retard side nate blow back to the intake engine side stability Better fuel Increasing overlap to in. throttle position and water temperature. idle rpm Better and stabilizing the idling rpm fuel economy for decreasing fast idle rota- tion Upon starting/ IN Eliminating overlap to elimi- Improved stopping the — EX Latest timing nate blow back to the intake startability engine side 2000 ECHO (NCF 171U) . economy At medium IN 3 crease internal EGR for Improved load EX To advance pumping loss elimination emission side control To advance side In low to Improved IN Advancing the intake valve medium speed torque in low 4 EX close timing for volumetric range with to medium heavy load BDC efficiency improvement speed range In high speed IN Retarding the intake valve Improved range with 5 EX To retard side close timing for volumetric output heavy load efficiency improvement Eliminating overlap to pre- vent blow back to the intake IN side for reduction of fuel in. ECM uses signal from the camshaft position sensor and the crankshaft position sensor to detect the actual valve timing. intake air volume. In addition. thus performing feedback control to achieve the target valve timing. the ECM calculates an optimal valve timing under each driving condition and control the camshaft timing oil control valve. RM750U). D The fresh air valve characteristics of the charcoal canister have been changed. Evaporative Emission Control A vacuum method for detecting a leakage in the evaporative emission control system has been adopted. No. D DTCs (Diagnostic Trouble Codes) have been added. 2000 ECHO (NCF 171U) . This method forcefully introduces the purge vacuum into the entire evaporative system and monitors the changes in the pressure. RM750U). refer to the 2000 ECHO Repair Manual (Pub. D A VSV (for Canister Closed Valve) has been provided between the fresh air valve and the charcoal canister. refer to the 2000 ECHO Repair Manual (Pub. For details. The main characteristics of the vacuum method are described below. Diagnosis System The diagnostic trouble codes can be output via DLC3 to an OBD-II scan tool or a hand-held tester. ECM VSV (for EVAP) Charcoal Vapor Pressure Sensor Canister Fuel Tank To Air Intake Chamber From Air Cleaner VSV (for Canister Closed Valve) 171EG25 8. D A vapor pressure sensor has been provided in the fuel tank in order to further ensure the precision of the vapor pressure sensor. ENGINE — 1NZ-FE ENGINE 47 7. For details on the DTCs (Diagnostic Trouble Codes). No.