Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: IG Power Supply Voltage (C1551)

DESCRIPTION

The power steering ECU assembly distinguishes the engine switch status as on (IG) or off through the IG power source circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Return-to-normal Condition

Note

C1551

IG Power Supply Voltage

Open or short in IG power source circuit with engine switch on (IG)

  • ECU-IG NO. 7 (w/o stop and start system)
  • IG power source circuit
  • Power steering ECU assembly

EPS warning light: Comes on

The ECU judges the system has returned to normal or the power switch is turned on (IG) again

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • If the power steering ECU assembly has been replaced, perform assist map writing and torque sensor zero point calibration.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (BATTERY - POWER STEERING ECU ASSEMBLY)

(a) Disconnect the J5 and J4 power steering ECU assembly connectors.

*a

Front view of wire harness connector

(to Power Steering ECU Assembly)

-

-

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

J4-1 (IG) - Body ground

Engine switch on (IG)

8 to 16 V

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J5-2 (PGND) - Body ground

Always

Below 1 Ω

OK

REPLACE POWER STEERING ECU ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

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