TCM Power Source Circuit [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 HARNESS AND CONNECTOR (TCM - BODY GROUND)
- Disconnect the TCM connectors.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition C25-2 (E1) - 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 (NO. 1 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - TCM)
- Remove the ECT-MAIN relay and ECU-IGP NO. 1 fuse.
- Disconnect the TCM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 3 (ECT-MAIN relay) - C25-1 (+B) Always Below 1 Ω 2 (ECU-IGP NO. 1 fuse) - C25-14 (IGP) Always Below 1 Ω 3 (ECT-MAIN relay) or C25-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 2 (ECU-IGP NO. 1 fuse) or C25-14 (IGP) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
GO TO HYBRID CONTROL SYSTEM (ECU POWER SOURCE CIRCUIT). Refer to ECU Power Source Circuit [09/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR