Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001H793
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for HV Model): C123A17; Supply Voltage Circuit Circuit Voltage Above Threshold; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

C123A17

Supply Voltage Circuit Circuit Voltage Above Threshold

DESCRIPTION

The power steering ECU with motor assembly distinguishes the power 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

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 power switch is turned on (IG) again

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

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 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for HV Model): CALIBRATION

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

PROCEDURE

1.

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

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

*a

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

Power 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

I42-2 (PGND) - Body ground

Always

Below 1 Ω
OK

REPLACE POWER STEERING ECU WITH MOTOR ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER ASSIST SYSTEMS: POWER STEERING ECU: REMOVAL 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2019]; POWER ASSIST SYSTEMS: POWER STEERING ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 09/2022]; POWER ASSIST SYSTEMS: POWER STEERING ECU: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR