1VD-FTV ENGINE

The configuration of the engine control system is as shown in the following chart.

Fuel Pressure Sensor

1. The fuel pressure sensor consists of a semiconductor which utilizes the characteristic of a silicon chip that changes its electrical resistance when pressure is applied to it. This sensor is mounted on the common-rail assembly, outputs a signal that represents the fuel pressure in the common-rail assembly to the ECM, in order to constantly regulate the fuel at an optimal pressure.

   

Manifold Absolute Pressure Sensor

1. The manifold absolute pressure sensor consists of a semiconductor which utilizes the characteristic of a silicon chip that changes its electrical resistance when pressure is applied to it. The sensor converts the intake air pressure into an electrical signal, and sends it to the ECM in an amplified form.

   

Crank Position Sensor

1. The timing rotor of the crankshaft consists of 34 teeth, with 2 teeth missing. The crank position sensor outputs the crankshaft rotation signals every 10°, and the missing teeth are used to determine the top-dead-center.

   

   *a	Timing Rotor (No.1 Crankshaft Position Sensor Plate)
   *b	NE Signal Plate (720° CA)
   *c	Crank Position Sensor
   *d	2 Teeth Missing

Cam Position Sensor

1. The cam position sensor generates one signal in every two revolutions of the crankshaft by using the timing trigger of the No. 2 camshaft timing sprocket.

   

   *1	Timing Trigger
   *2	No. 2 Camshaft Timing Sprocket
   *3	G Signal Plate (720° CA)
   *4	Cam Position Sensor

Throttle Position Sensor

1. The throttle position sensor is mounted on the diesel throttle body, to detect the opening angle of the throttle valve. The throttle position sensor converts the magnetic flux density that changes when the magnetic yoke (located on the same axis as that of the throttle valve shaft) rotates around the Hall IC into electric signals to operate the diesel throttle control motor.

   

Accelerator Pedal Sensor Assembly

1. The no-contact type accelerator pedal sensor assembly uses a Hall IC, which is mounted on the accelerator pedal arm.

2. A magnetic yoke is mounted at the base of the accelerator pedal arm. This yoke rotates around the Hall IC in accordance with the amount of effort that is applied to the accelerator pedal. The Hall IC converts the changes that occur in the magnetic flux into electrical signals, and outputs them in the form of accelerator pedal position signals to the ECM.

3. The Hall IC contains two circuits, one for the main signal, and the other for the sub signal. It converts the accelerator pedal position (angle) into electric signals that have differing characteristics and outputs them to the ECM.

   

   *1	Hall IC	*2	Magnetic Yoke
   *3	Accelerator Pedal Arm	-	-

   

Differential Pressure Sensor

1. The differential pressure sensor measures the pressure differences between before and after the DPF with PM in order to detect clogging.

2. The sensor is mounted on the transmission. The DPF and the sensor are connected with pipes and hoses.

   

   *1	Output Voltage
   *2	Differential Pressure
   *3	(kPa)
   *4	Differential Pressure Sensor

Exhaust Gas Temperature Sensor

1. An exhaust gas temperature sensor, which is a thermistor type, is installed before the oxidation catalyst, before the DPF and after the DPF, in order to detect the temperature of the exhaust gas.

   

   *1	Electric Resistance Value
   *2	Exhaust Gas Temperature

Air Fuel Ratio Sensor

1. A planar type air fuel ratio sensor is used.

2. The planar type air fuel ratio sensor uses alumina, which excels in heat conductivity and insulation, to integrate the sensor element with the heater, thus improving the warm-up performance of the sensor.

3. This sensor is based on a sensor developed for gasoline engines. The cover has been changed for diesel engine application in order to eliminate the influences of the sensor temperature and the PM. This sensor, which is mounted after the DPF, detects the air fuel ratio after the gas has been reduced.

   

   *1	Diffusion Resistance Layer	*2	Alumina
   *3	Platinum Electrode	*4	Heater
   *5	Atmosphere	*6	Sensor Element (Zirconia)

4. The air fuel ratio sensor data is approximately proportional to the existing air fuel ratio. The air fuel ratio sensor converts the oxygen density to a current and sends it to the ECM.

5. As a result, the detection precision of the air fuel ratio has been improved. The air fuel ratio sensor data can be read using an Global TechStream (GTS).

   

The ECM calculates two types of values: the basic injection volume and the maximum injection volume. Then, the ECM compares the basic and maximum injection volumes, and determines a smaller calculated value to be the final injection volume.

Figure 2. Basic Injection Volume

Figure 3. Maximum Injection Volume

Figure 4. Final Injection Volume Decision

Fuel injection timing is controlled as shown below.

Injection Timing Control

1. To determine the starting injection timing, the target injection timing is corrected in accordance with the starter signals, engine coolant temperature, and engine speed. When the engine coolant temperature is low, if the engine speed is high, the injection timing is advanced.

   

   *1	Starter Signal
   *2	Target Injection Timing Correction
   *3	Engine Coolant Temperature Sensor
   *4	Crank Position Sensor

Idle speed is controlled as shown below.

System Operation

1. General

   
   

   • The ECM controls the opening of the Suction Control Valve (SCV) in order to regulate the volume of fuel that is pumped by the supply pump assembly to the common-rail assembly. Consequently, the fuel pressure in the common-rail assembly is controlled to the target injection pressure.

2. SCV Opening Small

   
   

   • (a) When the opening of the SCV is small, the fuel suction area is kept small, which decrease the transferable fuel quantity.

   • (b) The plunger strokes fully, however, the suction volume becomes small due to the small suction area. Therefore, the difference of the volume between the geometry volume and the suction volume is in vacuum condition.

   • (c) Pumping will start at the time when the fuel pressure has become higher than the common-rail assembly pressure.

   

3. SCV Opening Large

   
   

   • (a) When the opening of the SCV is large, the fuel suction area is kept large, which increase the transferable fuel quantity.

   • (b) If the plunger strokes fully, the suction volume will increase because the suction area is large.

   • (c) Pumping will start at the time when the fuel pressure has become higher than the common-rail assembly pressure.

   

   *1	Fuel Pumping Mass
   *2	Pumping Starting Point
   *3	Cam Stroke
   *4	Large Suction Area

During pilot injection, the pilot injection volume, timing, and interval (between pilot injection and main injection) are controlled as shown below.

The opening of the throttle valve is controlled by the ECM in accordance with engine conditions. As a result, the noise that is generated during idling and deceleration, as well as the noise and vibration that are generated when the engine is stopped, have been reduced.

*1	Diesel Throttle Control Motor	*2	ThrottlePosition Sensor
*3	ECM	*4	Atmospheric Pressure Sensor
*5	Engine Speed	*6	Vehicle Speed
*7	Engine Coolant Temperature	*8	Intake Air Temperature
*9	Accelerator Pedal Position	*10	Intake Air Pressure
*11	Starter Signal	-	-

Construction

1. General

   
   

   • Variable nozzle vane device is established on the turbine wheel (exhaust) side, and consisted of a DC motor, nozzle vane position sensor, linkage, drive arm, unison ring, driven arms and nozzle vanes.

   

   *1	Turbine Wheel	*2	Linkage
   *3	Nozzle Vane Position Sensor	*4	DC Motor
   *5	Nozzle Vane	*6	Driven Arm
   *7	Unison Ring	*8	Drive Arm

2. Nozzle Vane Position Sensor

   
   

   • The nozzle vane position sensor consists of a Hall IC and a magnetic yoke that rotates in unison with the movement of the linkage that actuates the nozzle vane. The nozzle vane position sensor converts the changes in the magnetic flux that are caused by the rotation of the DC motor (hence, the rotation of the magnetic yoke) into electric signals, and outputs them to the turbo motor driver*1 or ECM*2. The turbo motor driver determines the actual nozzle vane position from the electric signals in order to calculate the target nozzle vane position.*1

   
   

   • *1: Except models compliant with EURO 5 emission regulations

   • *2: Models compliant with EURO 5 emission regulations

   

   Figure 7. System Diagram

   

Operation

1. At Engine Low Speed Range

   
   

   • When the engine is running in a low speed range, the DC motor pulls up the linkage by a signal from the turbo motor driver*1 or ECM*2. The tip of the linkage rotates the unison ring counterclockwise through a drive arm. The unison ring contains a driven arm, which is placed through the cutout portion of the unison ring. This driven arm also moves in the direction of the rotation of the unison ring. The fulcrum of the driven arm is an axis that is integrated with the nozzle vane behind the plate. When the driven arm moves counterclockwise, the nozzle vane moves toward the closing direction. This results in increasing the velocity of the exhaust gas flowing to the turbine, as well as the speed of the turbine. As a result, torque is improved when the engine is running at low speeds.

   
   

   • *1: Except models compliant with EURO 5 emission regulations

   • *2: Models compliant with EURO 5 emission regulations

   

   *1	Nozzle Vane	*2	Plate
   *3	Unison Ring	*4	Linkage
   *5	Driven Arm	*6	Drive Arm
   *a	Gas Flow	*b	Cutout Portion
   *c	Fulcrum	-	-

2. At Engine Medium-to-High Speed Range

   
   

   • When the engine is running in a medium-to-high speed range, the DC motor presses down the linkage by a signal from the turbo motor driver*1 or ECM*2. With this, the driven arm moves clockwise and this opens the nozzle vane and holds the specified supercharging pressure. Thus, lowering the back pressure and improving the output and fuel consumption.

   
   

   • *1: Except models compliant with EURO 5 emission regulations

   • *2: Models compliant with EURO 5 emission regulations

   

The meter ECU determines if the fuel pump control system is malfunctioning based on the fuel amount in the fuel tank sub-assembly and fuel sub tank sub-assembly. When the meter ECU detects that the fuel amount in the fuel tank sub-assembly is small (20.7 liters [21.9 US qts, 18.2 Imp. qts] or less) and the amount in the fuel sub tank sub-assembly is large (7.8 liters [8.2 US qts, 6.9 Imp. qts] or more), it determines that fuel has not been transferred from the fuel sub tank sub-assembly to the fuel tank sub-assembly. The meter ECU then blinks the low fuel warning light in the combination meter to inform the driver of the fuel pump control system malfunction. In addition, the master warning light comes on, the buzzer sounds and the warning message (Check Fuel System) is displayed on the multi-information display on models with optitron display type combination meter.

By sensing the engine driving conditions and actual amount of the EGR valve opening, the ECM operates the EGR valve and diesel throttle control motor, and regulates the amount of exhaust gas.

Figure 8. System Diagram

*1	EGR Valve Position Sensor	*2	No. 1 EGR Valve
*3	EGR Cooler	*4	Diesel Throttle Control Motor
*5	No. 2 EGR Valve	*6	ECM
*7	Atmospheric Pressure Sensor	*8	Accelerator Pedal Sensor Assembly
*9	Crank Position Sensor	*10	Intake Mass Air Flow Meter sub-assembly
*11	Engine Coolant Temperature Sensor	*12	AtmosphericTemperature Sensor
*13	Manifold Absolute Pressure Sensor	-	-
	Exhaust Gas		Intake Air

Construction

1. This engine mounting consists primarily of the rubber portion, No. 1 fluid chamber, No. 2 fluid chamber, and diaphragm. Fluid is sealed in the No. 1 and No. 2 fluid chambers.

2. This engine mounting obtains a vacuum from the vacuum pump via the VSV. It utilizes the vacuum to pull the diaphragm down in order to open or close the passages that connect the No. 1 and No. 2 fluid chambers.

3. The No. 1 and No. 2 fluid chambers use two fluid passages: the No. 1 fluid passage that is always connected regardless of whether the diaphragm is open or closed; and the No. 2 fluid passage that is connected only when the diaphragm is open. The fluid flows back and forth between the No. 1 and No. 2 fluid chambers through these two passages in order to restrain the vibration.

   

   *1	Rubber	*2	Diaphragm
   *a	No.2 Fluid Passage	*b	No. 1 Fluid Passage
   *c	Vacuum Intake	*d	No. 2 Fluid Chamber
   *e	No. 1 Fluid Chamber	*f	Fluid

Operation

1. General

   
   

   • When the ECM determines that the engine speed and the vehicle speed are low, it controls the introduction of vacuum from the vacuum pump to the engine mounting by turning the VSV ON or OFF.

   • A hysteresis is provided for both the engine speed and the vehicle speed at the point in which the VSV switches from ON to OFF.

   • While the engine is cranking, the VSV is OFF.

   

2. When the VSV is OFF

   
   

   • When the ECM determines that the engine speed and vehicle speed exceed the specified value, it stops the introduction of vacuum into the engine mounting by turning the VSV OFF.

   • When no vacuum is introduced into the engine mounting, the diaphragm does not move, so the No. 1 fluid passage remains closed. In this state, the fluid passes only through the No. 1 fluid passage in order to flow back and forth between the No. 1 and No. 2 fluid chambers.

   

   *a	No Vacuum Introduced	*b	Diaphragm Stopped
   *c	Flow of Fluid in No. 1 Fluid Passage	-	-

3. When the VSV is ON

   
   

   • When the ECM determines that the engine speed and the vehicle speed are equal to or less than the specified value, it turns the VSV ON to introduce vacuum into the engine mounting.

   • When a vacuum is introduced into the engine mounting, it pulls the diaphragm down, causing the No. 2 fluid passage to open. As a result, a large volume of fluid flows back and forth between the No. 1 and No. 2 fluid chambers, thus minimizing the fluid resistance and softening the engine mounting characteristics.

   

   *a	Diaphragm Descends	*b	Vacuum Introduced
   *c	Flow of Fluid in No. 1 Fluid Passage	*d	Flow of Fluid in No. 2 Fluid Passage

Soot Volume Calculation Method

1. The soot volume largely depends on injection ending timing and air fuel ratio. The ECM calculates soot volume from this information as shown in the graphs below.

   

   Tech Tips

   The accumulated soot volume memorized in ECM can be reset using the following procedures.

   
   

   1. Switch the power source to IG-ON. Then, use the ODO/TRIP switch to turn ON the "TRIP A" display on the multi-information display.

   2. Switch the power source to OFF. While pushing the ODO/TRIP switch, switch the power source to IG-ON.

   3. With the power source in the IG-ON mode, keep holding the ODO/TRIP switch (for at least five seconds) with the multi-information display counting down as shown below.

   4. When the resetting is completed, the multi-information display will display "COMPLETE" for one second and the buzzer built into the combination meter will sound.

   

Operation

1. The DPF captures Particulate Matter (PM) in the exhaust gas to purify the exhaust gas. When the temperature of the DPF increases, the PM which has accumulated in the DPF is oxidized and emitted as CO2 and H2O.

2. If the PM which has accumulated in the DPF exceeds an expected amount, the temperature may be in danger of becoming extraordinarily high when the accumulated PM is oxidized, and there may be an abnormal increase in DPF pressure loss, which could lead to engine damage. For this reason, PM regeneration is necessary to regularly oxidize the PM accumulated in the DPF.

3. The ECM calculates the state of engine combustion via signals from each sensor. Based on this, the ECU calculates the amount of PM that has accumulated in the DPF ("A"). The ECM also uses signals from the exhaust gas temperature sensor to calculate the amount of accumulated PM that has been reduced by oxidation ("B"). In addition, the ECM calculates the amount of PM accumulated in the DPF based on "A" and "B".

4. When the amount of PM accumulated in the DPF exceeds a predetermined volume, PM regeneration will be forcibly performed to oxidize the PM. If the PM accumulation amount exceeds the predetermined volume, or if the output value of the differential pressure sensor exceeds a predetermined value, the ECM changes the combustion control in the following order: it increases the exhaust gas temperature, forcibly increases the DPF temperature by injecting the fuel from the exhaust fuel addition injector assemblies and oxidizes the PM accumulated in the DPF.

5. PM regeneration is automatically performed to keep the DPF normal. However, the DPF temperature cannot be increased enough to perform PM regeneration when driving at an extremely low speed or when driving for an extraordinarily short time. As this situation could be hazardous to the DPF if it continues for a long time, a warning needs to be given to the driver. At this time, "DPF FULL SEE OWNER'S MANUAL" will be displayed on the multi-information display as a warning message.

6. If the warning message is displayed, the driver can perform PM regeneration by driving at an appropriate speed or using the DPF switch with the vehicle idling. The message will disappear when the accumulated PM in the DPF decreases to the normal level.

7. When driving while "DPF FULL SEE OWNER'S MANUAL" is being displayed, "DPF FULL ENGINE SERVICE REQUIRED" will be displayed on the multi-information display. In this case, the driver can conduct PM regeneration using the DPF switch while idling.

8. In addition, if the driver keeps driving without conducting PM regeneration even though the warning message is displayed, PM will keep accumulating in the DPF which could cause a hazardous situation. In this case, the ECM controls the engine output and torque to protect the engine, and the MIL will turn on. In this situation, PM regeneration is not possible, and the driver will have to replace the DPF at a Toyota dealer.

   

   *1

   Multi-information Display

   *2

   DPF Switch

   Tech Tips

   
   

   • The ECM confirms activation of the oxidation catalyst by the output value of the exhaust gas temperature sensor exceeding the predetermined value.

   • When replacing the front exhaust pipe with a new one, it is necessary to perform initialization of the DPF deteriorate data history in the ECM by using a Global TechStream (GTS).

   • When replacing the ECM with a new one, it is necessary to read DPF deteriorate data history from the installed ECM and then transfer that data history to the new ECM by using a Global TechStream (GTS). When the DPF deteriorate data history is not transferred, Diagnostic Trouble Code (DTC) is stored in the ECM, and the MIL comes on.

   • When replacing both the front exhaust pipe and the ECM, it is necessary to perform initialization of the DPF deteriorate data history in the ECM using a Global TechStream (GTS). When DPF deteriorate history initialization is not performed, DTC is stored in the ECM and the MIL comes on.