NO.3 POWER ASSIST DIFFERS BETWEEN RIGHT AND LEFT TURNS [ELECTRIC POWER STEERING (EPS)]

id0603a2801000

Troubleshooting item

Power assist differs between right and left turns

Possible cause

•  Steering gear and linkage malfunction

•  EPS control module malfunction

•  Poor connection of EPS control module connector, terminal damage

•  The steering wheel angle neutral position automatic learning function has not been operated.

Note

•  The steering angle learned by the EPS control module is cleared when 1 min or more has elapsed after the ignition was switched off.

System wiring diagram

•  Not applicable

Connector diagram

•  Not applicable

Troubleshooting item	Power assist differs between right and left turns
Possible cause	• Steering gear and linkage malfunction • EPS control module malfunction • Poor connection of EPS control module connector, terminal damage • The steering wheel angle neutral position automatic learning function has not been operated. Note • The steering angle learned by the EPS control module is cleared when 1 min or more has elapsed after the ignition was switched off.
System wiring diagram	• Not applicable
Connector diagram	• Not applicable

Diagnostic Procedure

Step

Inspection

Results

Action

1

VERIFY EPS CONTROL MODULE DTCs

•  Switch the ignition off and maintain this condition approx. 1 min.

•  Switch the ignition ON (engine on).

•  Using the M-MDS, perform the EPS control module DTC inspection.
(See DTC INSPECTION.)

•  Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [ELECTRIC POWER STEERING (EPS) (E)].)

No

Go to the next step.

2

DETERMINE MALFUNCTIONING LOCATION

•  Switch the ignition off and maintain this condition 2 min or more.

•  Switch the ignition ON (engine on).

•  Drive 10 m {394 in} or above in a straight line at more than 10 km/h {6.2 mph}.

•  Is there recurrence of malfunction?

Yes

Perform wheel alignment inspection.

(See WHEEL ALIGNMENT PRE-INSPECTION.)

(See FRONT WHEEL ALIGNMENT [(E)].)

(See REAR WHEEL ALIGNMENT [(E)].)

Perform the repair completion verification.

No

Temporary error occurred while learning steering wheel angle neutral position.

There is not malfunction in the EPS system.

Repair completion verification

VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Has the malfunction symptom been eliminated?

Yes

Complete the symptom troubleshooting.

Explain to the customer what has been repaired.

No

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

Step	Inspection	Results	Action
1	VERIFY EPS CONTROL MODULE DTCs • Switch the ignition off and maintain this condition approx. 1 min. • Switch the ignition ON (engine on). • Using the M-MDS, perform the EPS control module DTC inspection. (See DTC INSPECTION.) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [ELECTRIC POWER STEERING (EPS) (E)].)
1		No	Go to the next step.
2	DETERMINE MALFUNCTIONING LOCATION • Switch the ignition off and maintain this condition 2 min or more. • Switch the ignition ON (engine on). • Drive 10 m {394 in} or above in a straight line at more than 10 km/h {6.2 mph}. • Is there recurrence of malfunction?	Yes	Perform wheel alignment inspection. (See WHEEL ALIGNMENT PRE-INSPECTION.) (See FRONT WHEEL ALIGNMENT [(E)].) (See REAR WHEEL ALIGNMENT [(E)].) Perform the repair completion verification.
2		No	Temporary error occurred while learning steering wheel angle neutral position. There is not malfunction in the EPS system.
Repair completion verification	VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR • Install/connect the part removed/disconnected during the troubleshooting procedure. • Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. Explain to the customer what has been repaired.
Repair completion verification		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1.