Dtc P1426 Differential Pressure Sensor Installation Error

Двигатель. Toyota Rav4. Aca30, 33, 38 Ala30
Система Управления Двигателем 2Ad-Fhv. Toyota Rav4. Aca30, 33, 38 Ala30

DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P1426)

CHECK CONNECTION OF VACUUM HOSE (DIFFERENTIAL PRESSURE SENSOR - VACUUM TRANSMITTING PIPE)

CHECK BLOCKAGE OF VACUUM HOSE AND TRANSMITTING PIPE

READ VALUE OF DIFFERENTIAL PRESSURE

DTC P1426 Differential Pressure Sensor Installation Error


DESCRIPTION

УКАЗАНИЕ:
  1. For more information on the differential pressure sensor and TOYOTA D-CAT*1, refer to the following procedures (see page RAV4_ACA30 RM000000XSN006X.html).
  2. If P1426 is present, refer to the DTC chart for TOYOTA D-CAT (see page RAV4_ACA30 RM000000XSN006X.html).
*1: Diesel Clean Advanced Technology.

Toyota Rav4. Aca30, 33, 38 Ala30.Система Управления Двигателем 2Ad-Fhv.Система Ecd. Dtc P1426 Differential Pressure Sensor Installation Error

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 before and after 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 is clogged with particulate matter (PM). When the ECM judges that a partially clogged condition exists, the ECM begins to perform DPNR catalyst regeneration.
*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
P1426
When output voltage from the differential pressure sensor indicates positive pressure as negative pressure (and vice versa)
(1 trip detection logic)
  1. Incorrect arrangement differential pressure sensor hose piping
  2. Differential pressure sensor vacuum hose is clogged
  3. Blockage in vacuum transmitting pipe sub-assembly
  4. Differential pressure sensor
  5. ECM

УКАЗАНИЕ:
  1. DTC P1425 (Differential pressure sensor circuit), DTC P1427 (Differential pressure sensor circuit low) and/or DTC P1428 (Differential pressure sensor high) will be present if there is an open or short malfunction in the differential pressure sensor circuit.
  2. After confirming DTC P1426, check the differential pressure in the "Powertrain / Engine and ECT / Data List / DPNR Differential Pressure" menu using the intelligent tester.

Reference:
Condition
Differential Pressure Output
Sensor Condition
Ignition switch on (IG)
Approximately 0 kPa
Normal
Always
3 kPa
Open or short circuit
3,000 rpm (No engine load)
Negative output
Incorrect arrangement of hose piping

MONITOR DESCRIPTION

In order to detect abnormality in the differential pressure sensor, the ECM always monitors output voltage from the sensor. When the sensor output voltage is a reversal of positive and negative pressure, the ECM interprets this as incorrect vacuum hose arrangement of the sensor, or determines that the vacuum hoses have clogged, thus the MIL will be illuminated.

INSPECTION PROCEDURE

1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P1426)

  1. Connect the intelligent tester to the DLC3.

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

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

  1. Read DTCs.

    Result:
    Display (DTC Output)
    		Proceed to
    P1426
    		A
    P1426 and other DTCs
    		B
    УКАЗАНИЕ:
    If codes other than P1426 are output, perform troubleshooting for those DTCs first.


B
GO TO DTC CHART
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.


    Toyota Rav4. Aca30, 33, 38 Ala30.Система Управления Двигателем 2Ad-Fhv.Система Ecd. Dtc P1426 Differential Pressure Sensor Installation Error

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



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.



NG
REPLACE CLOGGED PARTS
OK


4.READ VALUE OF DIFFERENTIAL PRESSURE

  1. Connect the intelligent tester to the DLC3.

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

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / DPNR Differential Pressure.

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

    Result:

    Condition
    		Differential Pressure Output
    		Sensor Condition
    Ignition switch on (IG)
    		Approximately 0 kPa
    		Normal
    Always
    		3 kPa
    		Open or short circuit
    3,000 rpm (No engine load)
    		Negative output
    		Incorrect arrangement of hose piping


OK
CHECK FOR INTERMITTENT PROBLEMS
NG

REPLACE DIFFERENTIAL PRESSURE SENSOR ASSEMBLY