DTC    P1425    Differential Pressure Sensor Circuit

DTC    P1427    Differential Pressure Sensor Circuit Low

DTC    P1428    Differential Pressure Sensor Circuit High

для подготовки Нажмите здесь


DESCRIPTION

УКАЗАНИЕ:
  1. For more information on the differential pressure sensor and TOYOTA D-CAT (*1) system: (See page Нажмите здесь).
  2. If P1425, P1427 and/or P1428 is present, refer to the DTC chart for TOYOTA D-CAT system (See page Нажмите здесь).


A085356E12

The two sensing chambers of the differential pressure sensor are mounted to monitor the pressure before and after the DPNR (*2) catalytic converter. The sensor itself is not located on the engine assembly in order to reduce the influence of vibration. The sensor is a semiconductor-type that is not influenced by exhaust gases.
The ECM compares the exhaust gas pressure in front of and behind the DPNR catalytic converter by monitoring the pressure using the upstream and downstream sensing chambers of the differential pressure sensor. If the difference between the pressure before and after the catalytic converter exceeds a predetermined level, the ECM judges that the catalytic converter has clogged with particulate matter (PM). When the ECM judges that a partially clogged condition exists, the ECM begins to perform DPNR catalyst regeneration.
When the output voltage of the sensor deviates from the normal operating range, the ECM interprets this as a malfunction of the sensor circuit, sets DTC P1425, P1427, or P1428 and illuminates the MIL.
*1: Diesel Clean Advanced Technology
*2: Diesel Particulate-NOx Reduction system

УКАЗАНИЕ:
If the vacuum hoses of the differential pressure sensor are incorrectly connected (crossed), the ECM interprets this as abnormal pressure difference, DTC P1426 (Differential Pressure Sensor [Installation]) will be set and the MIL will illuminate.


DTC No.
DTC Detection Condition
Trouble Area
P1425
Differential pressure sensor output voltage is less than 0.4 V, or more than 4.8 V for 3 seconds or more
(1-trip detection logic)
  1. Open or short in differential pressure sensor circuit
  2. Incorrect differential pressure sensor hose routing
  3. Differential pressure sensor
  4. ECM
P1427
Differential pressure sensor output voltage is less than 0.4 V for 3 seconds or more
(1-trip detection logic)
P1428
Differential pressure sensor output voltage is more than 4.8 V for 3 seconds or more
(1-trip detection logic)

УКАЗАНИЕ:
  1. DTC P1426 (Differential pressure sensor [installation]) will be present if there is incorrect vacuum hose routing to the differential pressure sensor.
  2. After confirming DTCs P1425, P1427 and P1428, check the differential pressure by selecting the following menus on the intelligent tester: "Powertrain / Engine and ECT / Data List / DPF Differential Pressure".

Reference: 
Condition
Differential Pressure Output
Sensor Condition
Ignition switch on (IG)
Approximately 0 kPa
Normal
Always
3 kPa
Open or short circuit
3000 rpm (No engine load)
Negative output
Incorrect arrangement of hose piping


MONITOR DESCRIPTION

In order to detect abnormality in the differential pressure sensor at any time, the ECM always monitors output voltage from the sensor. When the sensor output voltage deviates from the normal operating range (between 0.4 V and 4.8 V) for more than 3 seconds, the ECM interprets this as a malfunction in the sensor circuit and illuminates the MIL.

WIRING DIAGRAM


A157513E01


INSPECTION PROCEDURE

ПРИМЕЧАНИЕ:
After replacing the ECM, the new ECM needs registration (See page Нажмите здесь) and initialization (See page Нажмите здесь).

УКАЗАНИЕ:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

1.READ VALUE OF DIFFERENTIAL PRESSURE
  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on (IG).

  1. Turn the tester on.

  1. Enter the following menu items: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.

  1. Check that differential pressure is within the specification below.

    Result:

    Condition
    Differential Pressure
    Proceed to
    Always
    -5 kPa or less
    A
    Ignition switch on (IG)
    -4 kPa to 98 kPa
    B
    Always
    99 kPa
    C



B
CHECK FOR INTERMITTENT PROBLEMS (Нажмите здесь)

C
Перейдите к шагу 3
A


2.CHECK CONNECTION OF VACUUM HOSE (DIFFERENTIAL PRESSURE SENSOR - VACUUM TRANSMITTING PIPE)
  1. Check if the vacuum hose routing between the differential pressure sensor and the vacuum transmitting pipe is correct.

  1. Check that there is no exhaust gas leakage between the differential pressure sensor and the vacuum transmitting pipe.

    OK:
    There is no routing, no exhaust gas leakage.



NG
CORRECT TO NORMAL CONNECTION
OK


3.CHECK BLOCKAGE OF VACUUM HOSE AND TRANSMITTING PIPE

ПРЕДОСТЕРЕЖЕНИЕ:
Be careful of being burned by exhaust gases during the following inspection.

  1. Disconnect the vacuum hose (both upstream and downstream) on the differential pressure sensor.

  1. Start the engine.

  1. Check if there are exhaust gas pulsations from both vacuum hoses during idling.

    OK:
    There are exhaust gas pulsations.



NG
REPLACE CLOGGED PARTS
OK


4.CHECK HARNESS AND CONNECTOR (DIFFERENTIAL PRESSURE SENSOR - ECM)


    A160888E01
  1. Disconnect the differential pressure sensor connector.

  1. Disconnect the ECM connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance (Check for open):
    Tester Connection
    Condition
    Specified Condition
    B55-2 (PEX) - B31-120 (PEX)
    Always
    Below 1 Ω
    B55-3 (VC) - B31-74 (VCPX)
    Always
    Below 1 Ω
    B55-1 (E2) - B31-97 (EPEX)
    Always
    Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    Condition
    Specified Condition
    B55-2 (PEX) or B31-120 (PEX) - Body ground
    Always
    10 kΩ or higher
    B55-3 (VC) or B31-74 (VCPX) - Body ground
    Always
    10 kΩ or higher

  1. Reconnect the differential pressure sensor connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (DIFFERENTIAL PRESSURE SENSOR - ECM)
OK


5.REPLACE DIFFERENTIAL PRESSURE SENSOR ASSEMBLY
  1. Replace the differential pressure sensor assembly (See page Нажмите здесь).


NEXT


6.CHECK WHETHER DTC OUTPUT RECURS
  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on (IG) and turn the tester on.

  1. Clear the DTCs (See page Нажмите здесь).

  1. Start the engine and drive the vehicle for approximately 15 minutes.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.

    Result:

    Result
    Proceed to
    DTC P1425, P1427 and/or P1428 are output
    A
    DTC is not output
    B



B
SYSTEM IS OK
A

REPLACE ECM (Нажмите здесь)  


































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