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.

NOTE:

Before replacing the engine stop and start ECU, read the number of starter operations, total number of engine starts and write it into a new engine stop and start ECU.
Refer to REGISTRATION [10/2022 - ]
After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.
Refer to REGISTRATION [10/2022 - ]
After replacing the engine stop and start ECU assembly, perform learning of the external backup boost converter (eco run vehicle converter assembly).
Refer to REGISTRATION [10/2022 - ]
Inspect the fuses for circuits related to this system before performing the following procedure.
When the engine stop and start ECU or oil pump with solenoid assembly is replaced, check the oil pump with solenoid assembly.
Refer to REGISTRATION [10/2022 - ]

HINT:

If DTCs P060B-1C (Analog to Digital Converter Circuit Voltage Out of Range), P060B-49 (Analog to Digital Converter Internal Electronic Failure) or P060B-71 (Analog to Digital Converter Actuator Stuck) and P1644-00 (ECU Internal Error) are output simultaneously, perform troubleshooting for DTC P060B-1C, P060B-49 or P060B-71 first as it may have caused DTC P1644-00 to be stored.
Refer to DTC P060B-1C: Analog to Digital Converter Circuit Voltage Out of Range; DTC P060B-49: Analog to Digital Converter Internal Electronic Failure; DTC P060B-71: Analog to Digital Converter Actuator Stuck [10/2022 - ]
If DTCs P0615-11 (Starter Relay Circuit Short to Ground) and P1644-00 (ECU Internal Error) are output simultaneously, perform troubleshooting for DTC P0615-11 first as it may have caused DTC P1644-00 to be stored.
Refer to DTC P0615-11: Starter Relay Circuit Short to Ground [10/2022 - ]
Using the GTS, read the Freeze Frame Data before troubleshooting. System condition information is recorded as Freeze Frame Data the moment a DTC is stored. This information can be useful when troubleshooting.
Refer to FREEZE FRAME DATA [10/2022 - ]
DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.