COMBUSTION TYPE POWER HEATER SYSTEM, Diagnostic DTC:054, 056

DTC Code DTC Name
054 High Setting of Flame Cutout
056 Low Setting of Flame Cutout

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area
054 High Setting of Flame Cutout Combustion ends abnormally (High output operation).

  • Exhaust air duct

  • Intake air duct

  • Fuel pump filter

  • Heater pump assembly

  • Heater assembly
056 Low Setting of Flame Cutout Combustion ends abnormally (Low output operation).

  • Exhaust air duct

  • Intake air duct

  • Fuel pump filter

  • Heater pump assembly

  • Heater assembly

CAUTION / NOTICE / HINT

Tech Tips

Before performing the following procedure, attempt to restart the heater assembly. If the heater assembly is successfully started, confirm that neither DTC 054 nor DTC 056 is output. If neither DTC 054 nor 056 is output, finish troubleshooting because it can be concluded that the system has returned to normal operation.

PROCEDURE


  1. INSPECT INTAKE AIR DUCT


    1. Inspect the intake air duct.

      Result
      Result Proceed to
      There is no problem with the intake air duct A
      The intake air duct is clogged, or other problems are found B

    B

    CLEAN OR REPLACE INTAKE AIR DUCT

    A

  2. INSPECT EXHAUST AIR DUCT


    1. Inspect the exhaust air duct.

      Result
      Result Proceed to
      There is no problem with the exhaust air duct A
      The exhaust air duct is clogged, or other problems are found B

    B

    CLEAN OR REPLACE EXHAUST AIR DUCT

    A

  3. INSPECT HEATER PUMP ASSEMBLY


    1. A01QPMMN01

      Remove the heater pump assembly connector.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (B2) - 2 (E2) Always 9 to 12 Ω

    3. Inspect heater pump assembly operation.


      1. Connect a positive (+) lead from the battery to terminal 1 (B2) and a negative (-) lead to terminal 2 (E2), and check the pressure of the hose by hand.

        Note

        This inspection must be done quickly (within 10 seconds) to prevent damage to the heater pump assembly.

        OK
        The pressure is applied to the hose.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEATER PUMP ASSEMBLY Click here

    OK

  4. CHECK FUEL PUMP FILTER


    1. Replace the fuel filter with a new one and check that the condition returns to normal.

      OK
      The heater is ignited normally and starts operating.
      Result
      Proceed to
      OK
      NG

    OK

    END (FUEL PUMP FILTER IS DEFECTIVE)

    NG

    REPLACE HEATER ASSEMBLY Click here