POWER ASSIST DIFFERS BETWEEN RIGHT AND LEFT TURNS [ELECTRIC POWER STEERING (EPS)]

id0603a2802600

Troubleshooting item

Power assist differs between right and left turns

Possible cause

•  Steering gear and linkage malfunction.

•  Electric Power Steering (EPS) control module malfunction.

•  Poor connection of Electric Power Steering (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 Electric Power Steering (EPS) control module is cleared when 1 min or more has elapsed after the main power was switched OFF.

Troubleshooting item	Power assist differs between right and left turns
Possible cause	• Steering gear and linkage malfunction. • Electric Power Steering (EPS) control module malfunction. • Poor connection of Electric Power Steering (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 Electric Power Steering (EPS) control module is cleared when 1 min or more has elapsed after the main power was switched OFF.

Diagnostic Procedure

Step

Inspection

Results

Action

1

VERIFY ELECTRIC POWER STEERING (EPS) CONTROL MODULE DTCS

•  Switch the main power OFF and maintain this condition approx. 1 min.

•  Switch the main power ON (READY on).

•  Using the M-MDS, perform the Electric Power Steering (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) CONTROL MODULE].)

No

Go to the next step.

2

DETERMINE MALFUNCTIONING LOCATION

•  Switch the main power OFF and maintain this condition 2 min or more.

•  Switch the main power ON (READY 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.)

(See REAR WHEEL ALIGNMENT.)

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 [L.H.D. (E)].)

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [R.H.D.].)

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

Step	Inspection	Results	Action
1	VERIFY ELECTRIC POWER STEERING (EPS) CONTROL MODULE DTCS • Switch the main power OFF and maintain this condition approx. 1 min. • Switch the main power ON (READY on). • Using the M-MDS, perform the Electric Power Steering (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) CONTROL MODULE].)
1		No	Go to the next step.
2	DETERMINE MALFUNCTIONING LOCATION • Switch the main power OFF and maintain this condition 2 min or more. • Switch the main power ON (READY 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.) (See REAR WHEEL ALIGNMENT.) 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 [L.H.D. (E)].) (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [R.H.D.].) If the CAN communication is normal, perform the diagnosis from Step 1.