STA Signal Circuit [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.
- READ VALUE USING GTS (STARTER SW)
- Enter the following menus: Powertrain / Engine / Data List / Starter SW.
Powertrain > Engine > Data List
Tester Display Starter SW - Read the values displayed on the GTS when the ignition switch is ON and on (START).
OK
GTS Display Switch Condition Normal Condition Starter SW Ignition switch ON OFF Ignition switch START ON Result
Proceed to OK NG
Result:
OK
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE [10/2022 - ]
Result:
NG
See step 2
- Enter the following menus: Powertrain / Engine / Data List / Starter SW.
- CHECK HARNESS AND CONNECTOR (ECM - ST NO. 1 RELAY)
- Disconnect the engine stop and start ECU connector.
- Disconnect the ECM connector.
- Remove the ST NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A16-16 (STA) - ST NO. 1 relay terminal 2 Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE [10/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR