Dtc 054 High Setting Of Flame Cutout

Heater & Air Conditioning System. Lexus Is250, Is220D. Gse20 Ale20
Heater. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

INSPECTION PROCEDURE

INSPECT INTAKE AIR DUCT

INSPECT EXHAUST AIR DUCT

INSPECT HEATER FUEL PUMP

REPLACE FUEL PUMP FILTER

DTC 054 High Setting of Flame Cutout

DTC 056 Low Setting of Flame Cutout


DESCRIPTION


DTC No.
DTC Detection Condition
Trouble Area
054
Combustion ends abnormally (High output operation).
  1. Exhaust air duct
  2. Intake air duct
  3. Fuel pump filter
  4. Heater fuel pump
  5. Combustion heater assembly
056
Combustion ends abnormally (Low output operation).

INSPECTION PROCEDURE

HINT:
Before performing the following inspections, attempt to restart the combustion heater assembly. If the combustion 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.
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 FUEL PUMP


    Lexus Is250, Is220D. Gse20 Ale20.Heater.Combustion Type Power Heater System.
Dtc
  054  High Setting Of Flame Cutout
  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester connection
    Condition
    Specified condition
    Q55-2 - Q55-1
    Always
    9 to 12 Ω
  1. Inspect heater fuel pump operation.

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

      NOTICE:
      This inspection must be done quickly (within 10 seconds) to prevent damage to the heater fuel pump.
      OK:
      The pressure is applied to the hose.


NG
REPLACE HEATER FUEL PUMP
OK


4.REPLACE FUEL PUMP FILTER
  1. Replace the fuel filter with a normal one and check that the condition returns to normal.

    OK:
    The heater is ignited normally and it starts operating.


OK
END
NG

REPLACE COMBUSTION HEATER ASSEMBLY