Steering Wheel Turning Force Is Heavy or Light

Steering Wheel Turning Force is Heavy or Light

SYMPTOM: Steering wheel turning force is heavy or light, while driving.

DIAGNOSTIC PROCEDURE
1. CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to STC-13, "SELF-DIAG RESULTS MODE". Electronically Controlled Power Steering System (EPS)
Is the CAN COMM CIRCUIT [U1000] displayed?
YES >> Perform trouble diagnosis for CAN communication line. Refer to STC-18, "DTC U1000 CAN COMM CIRCUIT". Electronically Controlled Power Steering System (EPS)
NO-1 >> With ABS: GO TO 2.
NO-2 >> Without ABS: GO TO 3.

2. CHECK VEHICLE SPEED SIGNAL FROM ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-19, "SELF-DIAGNOSIS". Testing and Inspection
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 4.

3. CHECK VEHICLE SPEED SIGNAL FROM TRANSMISSION CONTROL MODULE (TCM)
Perform self-diagnosis with TCM. Refer to CVT-54, "SELF-DIAGNOSTIC RESULT MODE". With Manufacturer's Scan Tool
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 4.

4. CHECK COMBINATION METER SIGNAL
Perform self-diagnosis with combination meter. Refer to DI-15, "SELF-DIAGNOSTIC RESULTS". Testing and Inspection
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 5.

5. CHECK ENGINE STATUS SIGNAL
Perform self-diagnosis for ECM. Refer to EC-116, "SELF-DIAG RESULTS MODE". Testing and Inspection
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 6.

6. CHECK EPS MOTOR SYSTEM
Perform trouble diagnosis for EPS motor. Refer to STC-17, "DTC C1606 EPS MOTOR". C1606
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.

7. CHECK EPS CONTROL UNIT
Check EPS control unit input/output signal. Refer to STC-11, "EPS Control Unit Input/Output Signal Reference Values". EPS Control Unit Input/Output Signal Reference Values
OK or NG
OK >> GO TO 8.
NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

8. SYMPTOM CHECK
Check again.
OK or NG
OK >> INSPECTION END
NG >> Check the steering wheel turning force because there may be mechanical malfunction. Refer to PS-6, "CHECKING STEERING WHEEL TURNING FORCE". Checking Steering Wheel Turning Force