Connect connector A of the DTC tester to the vehicle wire harness, and connector B of the DTC tester to the power heater connector.

Waveform 1:

If the normal system code is displayed during a DTC check even through the problem still occurs, check the circuits for each problem symptom in the order given in the table below, and proceed to the relevant troubleshooting.

Lexus IS250 IS220d GSE20 ALE20 HEATER

This system burns fuel to enhance the heating effect by heating the water between the engine and the heater core. This system, which consists of a combustion heater assembly, power heater switch, and a heater fuel pump operates when the engine is running and the power heater switch is turned on.

Lexus IS250 IS220d GSE20 ALE20 HEATER

Lexus IS250 IS220d GSE20 ALE20 HEATER

When disconnecting the negative (-) battery terminal, initialize the following systems after the terminal is reconnected.

Install the air conditioning amplifier with the screw and connect the connector.

Disengage the 6 claws and remove the front door opening trim cover RH.