Caution / Notice / Hint

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during engine stop and start ECU removal/installation are shown below.

NECESSARY PROCEDURES AFTER PARTS REMOVED/INSTALLED/REPLACED

Replaced Part or Performed Procedure	Necessary Procedure	Effect/Inoperative Function when Necessary Procedure not Performed	Link
Battery terminal is disconnected/reconnected	Operate the multiplex network master switch assembly (retractable outer mirror switch) to extend and retract the outer rear view mirror assembly	Parking Support Brake System*	Refer to INITIALIZATION [10/2022 - ]
Replacement of engine stop and start ECU	Update ECU security key	Vehicle Control History (RoB) are stored	Refer to UPDATE ECU SECURITY KEY [10/2022 - ]
Replacement of engine stop and start ECU	Upload the number of starter operations Perform external backup boost converter (eco run vehicle converter assembly) existence learning Reset air conditioning information Learning air conditioning information Check the oil pump with solenoid assembly	Stop and Start System	Refer to REGISTRATION [10/2022 - ]

*: When "[Parking Support Brake System icon] System Stopped See Owner's Manual" is displayed on the multi-information display.

NOTE:

To prevent the key from being locked in the vehicle, make sure to enter e-latch inspection mode and enable the manual release handle before disconnecting the cable from the negative (-) battery terminal.
Refer to INSPECTION MODE PROCEDURE [10/2022 - ]
After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) battery terminal.
Refer to BEFORE DISCONNECTING BATTERY [10/2022 - ]

HINT:

When the cable is disconnected / reconnected to the battery terminal, systems temporarily stop operating. However, each system has a function that completes learning the first time the system is used.

LEARNING COMPLETES WHEN VEHICLE IS DRIVEN

Effect/Inoperative Function when Necessary Procedure not Performed	Necessary Procedure	Link
Stop and Start System	Idle the engine for approximately 5 to 60 minutes or drive the vehicle until stop and start control is permitted.	Refer to PRECAUTION [10/2022 - ]
Front Camera System	Drive the vehicle straight ahead at 15 km/h (10 mph) or more for 1 second or more.	Refer to INITIALIZATION [10/2022 - ]
Adaptive High Beam System
Lighting System (w/ Automatic Headlight Beam Level Control System)

LEARNING COMPLETES WHEN VEHICLE IS OPERATED NORMALLY

Effect/Inoperative Function when Necessary Procedure not Performed	Necessary Procedure	Link
Power Back Door System	Reset back door close position	Refer to INITIALIZATION [10/2022 - ]
Air Conditioning System	After the ignition switch is turned to ON, the servo motor standard position is recognized.	-

COMPONENTS (REMOVAL)

Fig 1: Engine Stop And Start ECU Removal Components

Procedure		Part Name Code
1	READ NUMBER OF STARTER OPERATIONS	-	See step 1	-	-
2	NEGATIVE BATTERY TERMINAL	-	-	-	-
3	ECU INTEGRATION BOX LH	82878	-	-	-
4	ENGINE STOP AND START ECU	89981	-	-	-