Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001KGXL
Model Year Start: 2020 Model: GR Corolla Prod Date Range: [09/2019 - 09/2022]
Title: POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for Gasoline Model): C155A16,...,C155B17; Power Steering Motor "A" Supply Voltage Circuit Voltage Below Threshold; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 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 with motor assembly

EPS warning light: Comes on

Ignition switch ON 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 with motor assembly

EPS warning light: Comes on

Ignition switch ON 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 with motor assembly

EPS warning light: Comes on

Ignition switch ON 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 with motor assembly

EPS warning light: Comes on

Ignition switch ON 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 Hatchback GR Corolla [09/2019 - 09/2022]; POWER ASSIST SYSTEMS: POWER STEERING SYSTEM (for Gasoline Model): CALIBRATION

  • 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 with Motor 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 WITH MOTOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR