System description 2AD-FHV

 

ENGINE CONTROL SYSTEM

ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30



 

TOYOTA D-CAT DESCRIPTION



     
  1. Diesel Clean Advanced Technology (TOYOTA D-CAT) comprehensively regulates engine control (consists of a catalytic system and a fuel injection system) that purifies both particulate matter (PM) and nitrogen oxides (NOx) discharged by diesel engines. The catalytic system purifies hydrocarbons (HC) and carbon monoxides (CO), and reduces PM and NOx with a catalytic converter with the Diesel Particulate-NOx Reduction system (DPNR). The fuel injection system adds fuel into the exhaust port using the exhaust fuel addition injector to produce a RICH state for NOx reduction and maintain a proper catalyst temperature for DPNR catalyst regeneration.


    ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30
     

     

  2. TOYOTA D-CAT components:
     

    Component Description
    DPNR catalytic converter Reduces HC, CO, PM, and NOx.
    Exhaust fuel addition injector Adds fuel into the exhaust port in order to produce RICH air-fuel ratio for NOx reduction. Also, raises catalyst temperature for DPNR catalyst regeneration.
    Exhaust gas temperature sensor Used for estimating DPNR catalytic converter temperature and adjusting fuel addition by ECM while DPNR catalyst regeneration is performed. Also, detects DPNR catalytic converter temperature to prevent the catalytic converter temperature from rising too high.
    Differential pressure sensor Detects the volume of PM deposits and incorrect vacuum hose arrangement on the DPNR catalytic converter.
    A/F sensor Used for controlling air-fuel ratio. By controlling the air-fuel ratio, combustion control for low temperature combustion and DPNR catalyst regeneration are properly regulated.

     

  3. Diagnostic Trouble Codes (DTCs) table for TOYOTA D-CAT:

    УКАЗАНИЕ:

    This table indicates typical DTC combinations for each malfunction occurrence.

     

     
    Trouble Area Malfunction DTC No.
    DPNR catalytic converter Deteriorated or clogged P2002, P1601, P1386*
    Exhaust fuel addition injector Stuck open P1386
    Stuck closed P1386, P2002*
    Low fuel addition volume P1386, P2002*
    Open in exhaust fuel addition injector circuit P1386, P2047, P2002*
    Short in exhaust fuel addition injector circuit P1386, P2047
    Open or short in exhaust fuel addition injector P1386, P2047, P2002*
    Exhaust gas temperature sensor Open in exhaust gas temperature sensor circuit P0544, P0545, P0546, P1386, P2031, P2032, P2033
    Short in exhaust gas temperature sensor circuit P0544, P0545, P0546, P1386*, P2002*, P2031, P2032, P2033
    Exhaust gas temperature sensor P0544, P0545, P0546, P1386*, P2031, P2032, P2033
    Differential pressure sensor Open in differential pressure sensor circuit P1425, P1427, P2002*
    Short in differential pressure sensor circuit P1425, P1427, P2002*
    Differential pressure sensor P1425, P1427, P2002*
    Differential pressure sensor clogged P1426, P2002*
    Incorrect vacuum hose arrangement of the differential pressure sensor P1426, P2002*
    A/F sensor Open or short in A/F sensor or heater circuit P0031, P0032, P1386*, P2238, P2239, P2252, P2253
    A/F sensor P0031, P0032, P1386*, P2238, P2239, P2252, P2253
    Exhaust gas leaks Exhaust gas leaks P1386*, P2002*
    Fuel leaks Fuel leaks in fuel addition injector P1386*
    Supply pump Correct fuel pressure cannot be fed to the exhaust fuel addition injector P1386*

    УКАЗАНИЕ:

    *: There may be no DTC output depending on the condition of the malfunction.

     

     

  4. Diagnostic trouble code description for TOYOTA D-CAT:
     

    DTC No. Description
    P0031 Open or short in A/F sensor heater control circuit (low output)
    P0032 Open or short in A/F sensor or heater circuit (high output)
    P0544 Open or short in exhaust gas temperature sensor circuit (upstream)
    P0545 Open or short in exhaust gas temperature sensor circuit (upstream) (low output)
    P1386 Open or short in exhaust gas temperature sensor circuit (upstream) (high output)
    P1425 TOYOTA D-CAT fuel addition system malfunction
    P1426 Differential pressure sensor is clogged or has incorrect vacuum hose arrangement
    P1427 Open or short in differential pressure sensor circuit (low output)
    P1428 Open or short in differential pressure sensor circuit (high output)
    P2002 DPNR catalytic converter malfunction
    P2031 Open or short in exhaust gas temperature sensor circuit (downstream)
    P2032 Open or short in exhaust gas temperature sensor circuit (downstream) (low output)
    P2033 Open or short in exhaust gas temperature sensor circuit (downstream) (high output)
    P2047 Open in exhaust fuel addition injector circuit
    P2238 Open or short in A/F sensor or heater circuit (low output)
    P2239 Open or short in A/F sensor or heater circuit (high output)
    P2252 Open or short in A/F sensor or heater circuit (low output)
    P2253 Open or short in A/F sensor or heater circuit (high output)

     

COMMON RAIL SYSTEM DESCRIPTION



     
  1. Common rail system:
    The common rail system uses high-pressure fuel for improved fuel economy. This system also provides robust engine power, while suppressing engine vibration and noise.
    This system stores fuel in the common rail, which has been pressurized and supplied by the supply pump. By storing fuel at high-pressure, the common rail system can provide fuel at stable fuel injection pressures, regardless of engine speed or engine load.
    The ECM, using the EDU, provides an electric current to the piezo actuator in each injector to regulate the fuel injection timing and volume. The ECM also monitors the internal fuel pressure of the common rail using the fuel pressure sensor. The ECM causes the supply pump to supply the fuel necessary to obtain the target fuel pressure.
    In addition, this system uses a piezo actuator inside each injector to open and close the fuel passages. Therefore, both fuel injection time and fuel injection volume can be precisely regulated by the ECM.
    The common rail system allows a two stage fuel injection process. In order to soften combustion shock, this system performs "pilot-injection" prior to the main fuel injection. This helps to reduce engine vibration and noise.


    ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30
     

     

  2. Common rail system components:
     

    Component Description
    Common rail Stores high-pressure fuel produced by supply pump
    Supply pump Operated by crankshaft
    Supplies high-pressure fuel to common rail
    Injector Injects fuel to combustion chamber based on signals from ECM
    Fuel pressure sensor Monitors internal fuel pressure of common rail and sends signals to ECM
    Pressure Discharge Valve Based on signals from the ECM, opens valve when sudden deceleration has occurred, or when the ignition switch is off to prevent the fuel pressure from becoming too high.
    Suction control valve Based on signals from ECM, adjusts fuel volume supplied to common rail and regulates internal fuel pressure
    Check valve Keeps pressure that discharges from injector

     

  3. Diagnostic trouble codes (DTCs) table for the common rail system

    УКАЗАНИЕ:

    This table indicates typical DTC combinations for each malfunction occurrence.

     

     
    Trouble Area Malfunction DTC No.
    Injector Open or short in injector circuit P0200, P1238, P0093*
    Stuck open P0093, P1238
    Stuck closed P1238
    Fuel pressure sensor Open or short in fuel pressure sensor circuit or pressure sensor output fixed P0087, P0190, P0191, P0192, P0193
    Pressure discharge valve Open or short in pressure discharge valve circuit P1271, P1272, P0088*, P0093*, P1229*
    Stuck open P0093
    Stuck closed P1272, P0088*
    Suction control valve Open or short in suction control valve circuit P0627, P1229, P0088*
    Stuck open P1229, P0088*
    EDU Faulty EDU P0093*, P0200*, P1238*, P1271*, P1272*
    Common rail system (fuel system) Fuel leaks in high-pressure area P0093

    УКАЗАНИЕ:

    *: There may be no DTC output depending on the condition of the malfunction.

     

     

  4. Diagnostic trouble code description for the common rail system:
     

    DTC No. Description
    P0087 Fuel pressure sensor output does not change
    P0088 Internal fuel pressure too high (200 MPa [2,039 kgf/cm2, 29,007 psi] or more)
    P0093 Fuel leaks in high-pressure areas
    P0190 Open or short in fuel pressure sensor circuit (output voltage is too low or too high)
    P0192 Open or short in fuel pressure sensor circuit (output voltage is too low)
    P0193 Open or short in fuel pressure sensor circuit (output voltage is too high)
    P0200 Open or short in EDU or injector circuit
    P0627 Open or short in suction control valve circuit
    P1229 Fuel over-feed
INJECTION CONTROL SYSTEM DESCRIPTION

The ECM controls the fuel injection system through the EDU, injectors, and supply pump.
The ECM determines the injection volume and injection timing based on signals from the acceleration position sensor, crank position sensor, and camshaft position sensor. Based on the signals from the ECM, the EDU controls the injectors. The EDU also controls the suction control valve installed on the supply pump to help regulate fuel pressure.
The piezo type injector used in the 2AD-FHV engine makes noise when the engine is idling because this injector operates at high speed. Therefore, the EDU controls the injector to operate at low speed when the engine is idling based on signals from the ECM to achieve noise reduction.
The feed pump is used to pump fuel from the fuel tank to the supply pump.


ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30



 

SUPPLY PUMP OPERATION SYSTEM DESCRIPTION

The rotation of the eccentric cam in the supply pump causes the ring cam in the supply pump to push plunger A upward as illustrated below. The spring force pulls plunger B (located opposite to plunger A) upward. As a result, plunger B draws the fuel in, and plunger A pumps fuel out at the same time.


ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30


 

SUCTION CONTROL VALVE OPERATION SYSTEM DESCRIPTION

УКАЗАНИЕ:

The ECM controls the suction control valve operation to regulate the fuel volume that is produced by the supply pump for the common rail. This control is performed to regulate the internal fuel pressure of the common rail to the targeted injection pressure.

 




     
  1. Small opening of the suction control valve:
    (1) When the opening of the suction control valve is small, the volume of supplied fuel is small.
    (2) The suction volume becomes small due to the narrow path despite the plunger stroke being full. The difference between the geometrical volume and suction volume creates a vacuum.
    (3) Pump output will start when the fuel pressure at (A) becomes higher than the common rail pressure (B).


    ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30
     

     




  2.  
  3. Large opening of the suction control valve:
    (1) When the opening of the suction control valve is large, the volume of supplied fuel is increased.
    (2) If the plunger stroke is full, the suction volume becomes large because of the wide path.
    (3) Pump output will start when the fuel pressure at (A) becomes higher than the common rail pressure (B).


    ECD SYSTEM > System description 2AD-FHV Engine control  TOYOTA RAV4 / ACA30, 33, 38 ALA30