Certification ECU Communication Stop Mode [09/2023 - ]: Procedure
WARNING: This page is about a different car, the 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR OPEN IN CAN BUS LINES (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) BRANCH LINE)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the D38 certification ECU (smart key ECU assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition D38-1 (CANH) - D38-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))
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 D38-29 (E) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω - Reconnect the cable to the negative (-) auxiliary battery terminal.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition D38-6 (+B) - Body ground Ignition switch off 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [09/2023 - 12/2023] , or refer to REMOVAL [12/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
- Measure the resistance according to the value(s) in the table below.