Code No. P1273: Supply Pump Insufficient Flow


OPERATION



  • Refer to Code No. P0335: Crank Angle Sensor System .
  • Refer to Code No. P0340: Camshaft Position Sensor System .
  • Refer to Code No. P0003: Suction Control Valve Open .
  • Refer to Code No. P0004: Suction Control Valve Battery Short .

FUNCTION



  • The engine-ECU controls the fuel discharge rate using the suction control valve.
  • The engine-ECU monitors changes in the fuel discharge rate at each injection to detect a fault in one of the two plungers in the supply pump.

TROUBLE JUDGMENT


Check Condition
  • Vehicle in steady and stable state (the difference from the last data of the objective common rail pressure is less than 3 MPa and that from the last data of the final fuel injection rate is less than 2 mm3/st.
Judgment Criterion
  • The inter-cylinder difference in pressure feed exceeds the predetermined value 100 times consecutively.

FAIL-SAFE AND BACKUP FUNCTION



  • The rail pressure is controlled in the range between 50 and 60 MPa.
  • The fuel injection amount is restricted. (Output restriction)
  • The open angle of the accelerator pedal is restricted.
  • The throttle valve is closed (except the driving conditions that the fuel pressure exceeds the seizure resistance). (Fixed opening degree)
  • The EGR control is stopped (fully closed).
  • The DPF regeneration is prohibited.
  • The AS&G control is prohibited.

PROBABLE CAUSES



  • Air penetration due to lack of fuel
  • Failed supply pump
  • Failed engine-ECU

DIAGNOSIS PROCEDURE
note This diagnosis code is set for an air penetration in the fuel line of the supply pump due to lack of fuel. Therefore, bleed air from the fuel line after the fuel supply, and delete the diagnosis code through M.U.T.-III.

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

  • With the air released from the fuel line, supply fuel if necessary.
  • Continue idle operation for about 5 minutes.

Q. Is diagnosis code P1273 set again?
Go to Step 2.
The check is end.

STEP 2. Replace the supply pump assembly.

  • After the supply pump assembly, learn the supply pump (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns <4N1> ).
  • After replacing the supply pump assembly, re-check the trouble symptoms

Q. Does trouble symptom persist?
Replace the engine-ECU.
The check is end.