TERMINALS OF ECU
CHECK POWER STEERING ECU ASSEMBLY
| *a | Component without harness connected (Power Steering ECU Assembly) | - | - |
(a) Measure the voltage and resistance according to the value(s) in the table below.
NOTICE:
When the EPS warning light is illuminated due to a malfunction, the fail-safe function may cause the voltage of the power steering ECU assembly terminals to become 0 V.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| J4-1 (IG) - Body ground | P - Body ground | IG power source | Engine switch on (IG) | 8 to 16 V |
| J4-7 (CANH) - J4-8 (CANL) | GR - W | CAN communication line | Engine switch off | 54 to 69 Ω |
| z8-1 (TRQ2) - z8-2 (TRQG2) | Y - G | Torque sensor 2 signal | Engine running and steering wheel not being turned (without load) | 2.3 to 2.7 V |
| Engine running and steering wheel being turned to the right with vehicle stopped | 1.2 to 2.5 V | |||
| Engine running and steering wheel being turned to the left with vehicle stopped | 2.5 to 3.8 V | |||
| z8-2 (TRQG2) - Body ground | G - Body ground | Torque sensor 2 ground | Always | Below 1 Ω |
| z8-3 (TRQV2) - z8-2 (TRQG2) | L - G | Torque sensor 2 voltage source | Engine switch on (IG) | 4.5 to 5.5 V |
| z8-7 (TRQV1) - z8-8 (TRQG1) | R - B | Torque sensor 1 voltage source | Engine switch on (IG) | 4.5 to 5.5 V |
| z8-8 (TRQG1) - Body ground | B - Body ground | Torque sensor 1 ground | Always | Below 1 Ω |
| z8-9 (TRQ1) - z8-8 (TRQG1) | W - B | Torque sensor 1 signal | Engine running and steering wheel not being turned (without load) | 2.3 to 2.7 V |
| Engine running and steering wheel being turned to the right with vehicle stopped | 2.5 to 3.8 V | |||
| Engine running and steering wheel being turned to the left with vehicle stopped | 1.2 to 2.5 V | |||
| J5-1 (PIG) - Body ground | W - Body ground | Power source | Always | 9 to 16 V |
| J5-2 (PGND) - Body ground | B - Body ground | Power ground | Always | Below 1 Ω |
If the result is not as specified, the ECU may be malfunctioning.
System Diagram
Lost Communication with ECM / PCM "A" (U0100,U0129,U023A)Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Power Steering System: How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT:
Use these procedures to troubleshoot the power steering system.
*: Use the Techstream.
PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP
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Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Dynamic Torque Control Awd System: Diameter of the Tire is not Uniform (C1337)
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