Lexus IS250 IS220d GSE20 ALE20 - HEATER
CHECK HARNESS AND CONNECTOR (COMBUSTION HEATER ASSEMBLY - HEATER FUEL PUMP)
CHECK HARNESS AND CONNECTOR (HEATER FUEL PUMP - BODY GROUND)
DTC 047 Short in Heater Fuel Pump Circuit
DTC 048 Heater Fuel Pump Malfunction
DTC 049 Heater Fuel Pump Output Error
DESCRIPTION
| DTC No. | DTC Detection Condition | Trouble Area |
| 047 | A short is detected in the heater fuel pump circuit. | Wire harness or connector between heater fuel pump and combustion heater assembly Wire harness or connector between heater fuel pump and body ground Heater fuel pump Combustion heater assembly |
| 048 | Operation stop of the heater fuel pump is detected. (Open in the circuit) |
Wire harness or connector between combustion heater assembly and heater fuel pump Wire harness or connector between heater fuel pump and body ground Heater fuel pump Combustion heater assembly |
| 049 | An error is detected in output to the heater fuel pump. | Wire harness or connector between combustion heater assembly and heater fuel pump Wire harness or connector between heater fuel pump and body ground Heater fuel pump Power heater ECU (combustion heater assembly) |
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.CHECK HARNESS AND CONNECTOR (COMBUSTION HEATER ASSEMBLY - HEATER FUEL PUMP) |
Disconnect the connector from the combustion heater assembly.
Disconnect the connector from the heater fuel pump.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester connection
(Symbols)Condition Specified condition A51-2 (L) - Q55-2 Always Below 1 Ω A51-2 (L) - Body ground Always 10 kΩ or higher
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| OK | |
| 2.CHECK HARNESS AND CONNECTOR (HEATER FUEL PUMP - BODY GROUND) |
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester connection
(Symbols)Condition Specified condition Q55-1 - Body ground Always Below 1 Ω
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| OK | |
| 3.INSPECT HEATER FUEL PUMP |
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
Inspect heater fuel pump operation.
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.
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| OK | ||
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LEXUS IS250, IS220d / GSE20 ALE20