ECU Power Source Circuit [06/2018 - 09/2022]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2022 Lexus ES 350, 2022 Lexus ES 250, 2021 Lexus ES 350, 2021 Lexus ES 250, and 2020 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (PARKING ASSIST ECU - BODY GROUND)
- Disconnect the N44 parking assist ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition N44-4 (GND1) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (PARKING ASSIST ECU POWER SOURCE)
- Disconnect the N44 parking assist ECU connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition N44-1 (+B) - N44-4 (GND1) Always 11 to 14 V N44-2 (ACC) - N44-4 (GND1) Engine switch on (ACC) 11 to 14 V Engine switch off Below 1 V N44-3 (IG) - N44-4 (GND1) Engine switch on (IG) 11 to 14 V Engine switch off Below 1 V Result
Proceed to OK NG
Result:
OK
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE [06/2018 - 09/2022]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR