POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for Gasoline Model): C123A17; Supply Voltage Circuit Circuit Voltage Above Threshold; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [09/2019

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001KGXH
Model Year Start: 2020	Model: GR Corolla	Prod Date Range: [09/2019 - 09/2022]
Title: POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for Gasoline Model): C123A17; Supply Voltage Circuit Circuit Voltage Above Threshold; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 09/2022]

DTC

C123A17

Supply Voltage Circuit Circuit Voltage Above Threshold

DESCRIPTION

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

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Return-to-normal Condition	Note
C123A17	Supply Voltage Circuit Circuit Voltage Above Threshold	IG voltage is 18.5 V or more	EPS-IG1 fuse IG power source circuit Power steering ECU with motor assembly	EPS warning light: Comes on	The ECU judges the system has returned to normal or the ignition switch is turned to ON again	-

NOTICE:

When the power steering ECU with motor assembly has been replaced, perform Power Steering ECU Initial Setting (torque sensor zero point calibration and assist map writing).
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.

1.	CHECK HARNESS AND CONNECTOR (BATTERY - POWER STEERING ECU WITH MOTOR ASSEMBLY)

(a) Disconnect the I42 and I21 power steering ECU with motor assembly connectors.

Front view of wire harness connector

(to Power Steering ECU with Motor Assembly)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
I21-1 (IG) - Body ground	Ignition switch ON	8 to 16 V

Standard Resistance:

Tester Connection	Condition	Specified Condition
I42-2 (PGND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR