Code No. P0093: Fuel Leak Problem


OPERATION



  • Refer to Code No. P0192: Rail Pressure Sensor Circuit Low Input .

FUNCTION



  • The engine-ECU monitors the signals input from the rail pressure sensor.
  • The engine-ECU controls the suction control valve so that necessary fuel pressure can be obtained before fuel injection.
  • The engine-ECU compares the fuel pressure immediately before fuel injection and the fuel pressure after injection to check whether. The pressure drop greatly exceeds the expected range determined based on fuel consumption. The engine-ECU detects fuel leaks in this way.

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
  • The engine speed is 600 r/min or more
  • Rail pressure sensor is normal
Judgment Criterion
  • The fuel discharge rate of the supply pump continues to exceed its threshold value against the fuel injection rate.

PROBABLE CAUSES



  • Fuel leakage or fuel line blocked
  • Failed injector
  • Failed suction control valve
  • Failed rail pressure sensor.
  • Harness damage in rail pressure sensor circuit or loose connector contact.
  • Failed engine-ECU

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q. Is any other diagnosis code than P0093 set?
Inspection chart for diagnosis codes (Refer to ).
Go to Step 2.

STEP 2. Detection of fuel line leakage

  • Check whether fuel is leaking from a high-pressure fuel line.

Q. Is the check result normal?
Go to Step 3.
Replace the parts of an abnormal location.

STEP 3. Release the air from the fuel line.

  • After releasing the air from the fuel line, continue idle operation for about five minutes and recheck for trouble symptoms.

Q. Does the trouble symptom persist?
Go to Step 4.
The check is end.

STEP 4. Connector check: A-44 rail pressure sensor connector and C-105 engine-ECU connector.


Q. Are the check results normal?

Go to Step 5.

Repair or replace the connector.

STEP 5. Check harness between A-44 (terminal No. 1) rail pressure sensor connector and C-105 (terminal No. 70) engine-ECU connector.


note Before checking harness, check intermediate connector A-131, and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 6.

Repair the damaged harness wire.

STEP 6. Check harness between A-44 (terminal No. 2) rail pressure sensor connector and C-105 (terminal No. 64) engine-ECU connector.


note Before checking harness, check intermediate connector A-131, and repair if necessary.

  • Check output line for damage.

Q. Is the check result normal?

Go to Step 7.

Repair the damaged harness wire.

STEP 7. Check harness between A-44 (terminal No. 3) rail pressure sensor connector and C-105 (terminal No. 88) engine-ECU connector.


note Before checking harness, check intermediate connector A-131, and repair if necessary.

  • Check earthing line for damage.

Q. Is the check result normal?

Go to Step 8.

Repair the damaged harness wire.

STEP 8. Detection of fuel leakage from injector body

  • Remove the injector. Check whether there is the evidence of the fuel leakage from the injector body.

Q. Is the check result normal?
Go to Step 9.
Replace the abnormal injector. After replacing the injector, register the injector identification code and learn fuel injection. (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

STEP 9. Replace the common rail assembly and fuel injection tubes.

  • After replacing the common rail assembly and fuel injection tubes, re-check the trouble symptoms.

Q. Does the trouble symptom persist?
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, the vehicle equipped with the DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Emission Control - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).
The check is end.