Dtc C1551 Ig Power Supply Voltage Malfunction

Steering. Yaris. Ncp93, 131
Power Assist Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING TECHSTREAM (IG POWER SUPPLY)

CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - IG CIRCUIT AND BODY GROUND)

DTC C1551 IG Power Supply Voltage Malfunction


DESCRIPTION

The power steering ECU assembly distinguishes the ignition switch status as ON or off through the IG power source circuit.

DTC No.
DTC Detection Condition
Trouble Area
C1551
Open or short in IG power source circuit with ignition switch ON.
  1. ECU-IG NO. 1 fuse
  2. IG power source circuit
  3. Power steering ECU assembly

WIRING DIAGRAM


Yaris. Ncp93, 131.Power Assist Systems.Power Steering System (For Sedan). Dtc C1551 Ig Power Supply Voltage Malfunction


INSPECTION PROCEDURE

NOTICE:
  1. If the power steering ECU assembly has been replaced, perform the torque sensor zero point calibration and assist map writing (YARIS_NCP93 RM000000OSZ018X.html).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.READ VALUE USING TECHSTREAM (IG POWER SUPPLY)

  1. Turn the ignition switch off.

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Enter the following menus: Chassis / EMPS / Data List.

  1. Select the item IG Power Supply in the Data List and read the value displayed on the Techstream.

    EMPS
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    IG Power Supply
    		IG power supply/
    Min.: 0.0000 V
    Max.: 20.1531 V
    		11 to 14 V
    		Ignition switch is ON


NG
Go to step 2
OK

USE SIMULATION METHOD TO CHECK (YARIS_NCP93 RM000000UZ309WX.html)

2.CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - IG CIRCUIT AND BODY GROUND)


    Yaris. Ncp93, 131.Power Assist Systems.Power Steering System (For Sedan). Dtc C1551 Ig Power Supply Voltage Malfunction

  1. Disconnect the power steering ECU assembly connectors.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D104-1 (IG) - Body ground
    		Ignition switch ON
    		11 to 14 V

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A68-2 (PGND) - Body ground
    		Always
    		Below 1 Ω
    Text in Illustration
    *a
    		Rear view of wire harness connector
    (to Power Steering ECU Assembly)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE POWER STEERING ECU ASSEMBLY (YARIS_NCP93 RM000002XN603ZX.html)