COMBUSTION TYPE POWER HEATER SYSTEM - ECU Power Source Circuit

DESCRIPTION

This is power source for the power heater ECU (combustion heater assembly).

Combustion Type Power Heater System - Ecu Power Source Circuit. HEATER. Lexus IS250 IS220d GSE20 ALE20

1.INSPECT FUSE (PWR HTR)

Remove the PWR HTR fuse from the engine room R/B and J/B No. 1.

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

REPLACE FUSE (PWR HTR)

OK

2.CHECK HARNESS AND CONNECTOR (POWER HEATER ECU (COMBUSTION HEATER ASSEMBLY) - BODY GROUND)

Remove the power heater ECU (combustion heater assembly).

Disconnect the connector from the power heater ECU (combustion heater assembly).

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

Standard resistance:
Tester connection
(Symbols) Condition Specified condition
A51-1 (E) - Body ground Always Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.CHECK HARNESS AND CONNECTOR (POWER HEATER ECU (COMBUSTION HEATER ASSEMBLY) - BATTERY)

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

Standard voltage:
Tester connection
(Symbols) Condition Specified condition
A51-5 (B) - Body ground Always 10 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

Inspection item	Condition	Specified condition
PWR HTR fuse	Always	Below 1 Ω

Tester connection (Symbols)	Condition	Specified condition
A51-1 (E) - Body ground	Always	Below 1 Ω