Code No. P2454: Exhaust Differential Pressure Sensor Circuit Low Input <Euro5b>




OPERATION



  • A power voltage of 5 V is applied to the exhaust differential pressure sensor power terminal (terminal No. 3) from the engine-ECU (terminal No. 94) and earthed to the engine-ECU (terminal No. 80) from exhaust differential pressure sensor (terminal No. 2).
  • The sensor signal is inputted to the engine-ECU (terminal No. 56) from the exhaust differential pressure sensor output terminal (terminal No. 1).

FUNCTION



  • The exhaust differential pressure sensor outputs the voltage to the engine-ECU in accordance with the difference in the voltage between the DPF upstream area and the DPF downstream area.
  • The engine-ECU anticipates the amount of PM accumulated in the DPF through this output voltage.

TROUBLE JUDGMENT


Check Conditions
  • Battery positive voltage is 8 - 16 V
  • 2 seconds later after the ignition switch has been in "ON" position or the engine has started up
Judgment Criterion
  • The exhaust differential pressure sensor output voltage is 0.49 V or less.

PROBABLE CAUSES



  • Failed exhaust differential pressure sensor
  • Open/short circuit or harness damage in exhaust differential pressure sensor circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 120: exhaust differential pressure sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Connector check: A-148 exhaust differential pressure sensor connector

Q. Is the check result normal?

Go to Step 3.

Repair or replace the connector.

STEP 3. Perform voltage measurement at A-148 exhaust differential pressure sensor connector.


  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?

Go to Step 9.

Go to Step 4.

STEP 4. Perform voltage measurement at C-105 engine-ECU connector.


  • Measure engine-ECU terminal voltage.
  • Ignition switch: ON
  • Voltage between terminal No. 94 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?

Go to Step 8.

Go to Step 5.

STEP 5. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Go to Step 6.

Repair or replace the connector.

STEP 6. Check harness between A-148 (terminal No. 3) exhaust differential pressure sensor connector and C-105 (terminal No. 94) engine-ECU connector.



  • Check power supply line for short circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the damaged harness wire.

STEP 7. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 120: exhaust differential pressure sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ). After registering the injector identification code, carry out the forcible DPF regeneration. (Refer to GROUP 17 - Emission Control - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).

STEP 8. Connector check: C-105 engine-ECU connector


Q. Is the check result normal?


    Check and repair harness between A-148 (terminal No. 3) exhaust differential pressure sensor connector and C-105 (terminal No. 94) engine-ECU connector.

    • Check power supply line for open circuit.

Repair or replace the connector.

STEP 9. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Go to Step 10.

Repair or replace the connector.

STEP 10. Check harness between A-148 (terminal No. 3) exhaust differential pressure sensor connector and C-105 (terminal No. 94) engine-ECU connector.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 11.

Repair the damaged harness wire.

STEP 11. Check harness between A-148 (terminal No. 1) exhaust differential pressure sensor connector and C-105 (terminal No. 56) engine-ECU connector.



  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 12.

Repair the damaged harness wire.

STEP 12. Replace the exhaust differential pressure sensor

  • After replacing the exhaust differential pressure sensor, carry out the forcible DPF regeneration. (Refer to GROUP 17 - Emission Control - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ). After carrying out the forcible DPF regeneration, re-check the trouble symptoms.

Q. Is the check result normal?
Go to Step 7.
Check end.