Toyota Yaris: Power Steering System / Problem Symptoms Table

Toyota Yaris XP210 (2020-2026) Reapir and Service Manual / Steering / Power Assist Systems / Power Steering System / Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table.
Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.

Power Steering System

Symptom	Suspected Area	Link
Heavy steering	Front tires (improperly inflated, unevenly worn)
	Front wheel alignment (incorrect)
	Front suspension (Lower ball joint)
	Steering gear assembly
	Auxiliary battery and power source circuit
	Power source voltage of power steering ECU assembly
	Power steering ECU assembly
	Vehicle condition (Steering wheel is turned from left to right repeatedly with vehicle stopped or heavy load is continuously applied to vehicle)
Heavy Steering (EPS Warning Light (Yellow))	Heavy Steering Feel (EPS Warning Light (Yellow))
Steering effort differs between right and left or is uneven	Power steering ECU zero point calibration not completed
	Front tires (improperly inflated, unevenly worn)
	Front wheel alignment (incorrect)
	Front suspension (Lower ball joint)
	Steering gear assembly
	Torque sensor (Electric power steering column sub-assembly)
	Electric power steering column sub-assembly
	Power steering ECU assembly
While driving, steering effort does not change in accordance with vehicle speed, or steering wheel does not return to its centered position easily	Skid control ECU (Brake actuator assembly)
	Speed sensor
	Torque sensor (Electric power steering column sub-assembly)
	Power steering ECU assembly
	CAN communication system
Friction sounds occur when turning steering wheel during low speed driving	Power steering motor (Power steering ECU assembly)
	Electric power steering column sub-assembly
	Spiral cable with sensor sub-assembly
	Steering column cover contacting steering wheel assembly
High-pitched sound (squeaking) occurs when turning steering wheel slowly with vehicle stopped	Power steering motor (Power steering ECU assembly)
	Steering wheel installation (incorrect)
Steering wheel vibrates and noise occurs when turning steering wheel from lock to lock	Power steering motor (Power steering ECU assembly)
	Electric power steering column sub-assembly
	Steering wheel installation (incorrect)
EPS warning light remains on	EPS warning light circuit

Calibration

CALIBRATION POWER STEERING ECU INITIAL SETTING (ASSIST MAP WRITING) (USING GTS) NOTICE: If any of the following conditions are met, perform Power Steering ECU Initial Setting (assist map writing): The power steering ECU assembly has been replaced...

Terminals Of Ecu

TERMINALS OF ECU CHECK POWER STEERING ECU ASSEMBLY *a Component without harness connected (Power Steering ECU Assembly) - - (a) Measure the voltage and resistance according to the value(s) in the table below...

Other information:

Toyota Yaris XP210 (2020-2026) Reapir and Service Manual: Lost Communication with Steering Angle Sensor Module Missing Message (U012687,U010087,U012987,U014087,U023A87)

DESCRIPTION The power steering ECU assembly receives signals from the steering sensor, skid control ECU (brake actuator assembly), forward recognition camera, ECM and clearance warning ECU assembly via CAN communication. DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Return-to-normal Condition Note U010087 Lost Communication With ECM/PCM "A" Missing Message Lost communication with ECM CAN communication system ECM EPS warning light: Does not come on After normal confirmation - U012687 Lost Communication with Steering Angle Sensor Module Missing Message Lost communication with steering sensor CAN communication system Steering sensor EPS warning light: Does not come on After normal confirmation - U012987 Lost Communication with Brake System Control Module Missing Message Lost communication with skid control ECU (brake booster with master cylinder assembly) CAN communication system Skid control ECU (Brake booster with master cylinder assembly)(for TMC Made HV Model) Skid control ECU (Brake actuator assembly)(for TMMF Made HV Model) EPS warning light: Does not come on After normal confirmation - U014087 Lost Communication with Body Control Module Missing Message Lost communication with main body ECU (multiplex network body ECU) CAN communication system Main body ECU (multiplex network body ECU) EPS warning light: Does not come on After normal confirmation - U023A87 Lost Communication with Image Processing Module "A" Missing Message Lost communication with forward recognition camera CAN communication system Forward recognition camera EPS warning light: Does not come on After normal confirmation w/ Toyota Safety Sense PROCEDURE 1...

Toyota Yaris XP210 (2020-2026) Reapir and Service Manual: Installation

INSTALLATION CAUTION / NOTICE / HINT CAUTION: Wear protective gloves. Sharp areas on the parts may injure your hands. HINT: Use the same procedure for the driver side and front passenger side. The procedure listed below is for the driver side. PROCEDURE 1...