Parking Assist ECU Communication Stop Mode [10/2022 - ]: Procedure
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.
- CHECK FOR OPEN IN CAN BUS LINES (PARKING ASSIST ECU BRANCH LINE)
- Disconnect the cable from the negative (-) battery terminal.
- Disconnect the H38 parking assist ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition H38-12 (CANH) - H38-13 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (PARKING ASSIST ECU)
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition H38-4 (GND1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω - Reconnect the cable to the negative (-) battery terminal.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition H38-1 (+B) - Body ground Always 11 to 14 V H38-2 (IG) - Body ground Ignition switch ON 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE PARKING ASSIST ECU. Refer to REMOVAL [10/2022 - 08/2023] , or refer to REMOVAL [08/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
- Measure the resistance according to the value(s) in the table below.