COMBUSTION TYPE POWER HEATER SYSTEM, Diagnostic DTC:054 and 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

Tip:

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. E267500N01

      Remove the heater pump assembly connector.

      Click hereClick 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 hereClick 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 hereClick here