Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM10000000257FB
Model Year Start: 2023 Model: Corolla Prod Date Range: [09/2022 -           ]
Title: POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for HV Model): C155A16,C155A17,C155B16,C155B17; Power Steering Motor "A" Supply Voltage Circuit Voltage Below Threshold; 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]

DTC

C155A16

Power Steering Motor "A" Supply Voltage Circuit Voltage Below Threshold

DTC

C155A17

Power Steering Motor "A" Supply Voltage Circuit Voltage Above Threshold

DTC

C155B16

Power Steering Motor "B" Supply Voltage Circuit Voltage Below Threshold

DTC

C155B17

Power Steering Motor "B" Supply Voltage Circuit Voltage Above Threshold

DESCRIPTION

If a problem occurs in the system, the power source relay circuit and the motor relay circuit are shut off to stop power assist. The ECU must be replaced when there is a problem with the relays because the relays are built into the ECU.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Return-to-normal Condition

Note

C155A16

Power Steering Motor "A" Supply Voltage Circuit Voltage Below Threshold

Motor "1" PIG voltage is 3.6 V or less

  • EPS fuse
  • PIG power source circuit
  • Power steering ECU assembly

EPS warning light: Comes on

Power switch on (IG) again

-

C155A17

Power Steering Motor "A" Supply Voltage Circuit Voltage Above Threshold

Diagnosis Condition: IG ON

Malfunction Status: Motor "1" PIG voltage is 19.6 V or more

  • EPS fuse
  • PIG power source circuit
  • Power steering ECU assembly

EPS warning light: Comes on

Power switch on (IG) again

-

C155B16

Power Steering Motor "B" Supply Voltage Circuit Voltage Below Threshold

Motor "2" PIG voltage is 3.6 V or less

  • EPS fuse
  • PIG power source circuit
  • Power steering ECU assembly

EPS warning light: Comes on

Power switch on (IG) again

-

C155B17

Power Steering Motor "B" Supply Voltage Circuit Voltage Above Threshold

Diagnosis Condition: IG ON

Malfunction Status: Motor "2" PIG voltage is 19.6 V or more

  • EPS fuse
  • PIG power source circuit
  • Power steering ECU assembly

EPS warning light: Comes on

Power switch on (IG) again

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

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

(a) Disconnect the I42 power steering ECU assembly connectors.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I42-1 (PIG) - Body ground

Always

9 to 16 V

*a

Front view of wire harness connector

(to Power Steering ECU Assembly)

(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 ASSEMBLY 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; POWER ASSIST SYSTEMS: POWER STEERING ECU: REMOVAL 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; POWER ASSIST SYSTEMS: POWER STEERING ECU: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR