DIAGNOSTIC CHART

Trouble

Possible cause

Corrective action

Steering effort is heavy in all ranges.
Steering effort is heavy at stand still.
Steering wheel vibrates when turning.

1. Pulley belt

Unequal length of pulley belts
Contact with oil or grease
Looseness or damage of the pulley belt
Poor uniformity of the pulley belt cross section
Pulley belt touches to pulley bottom
Poor revolution of pulleys (except oil pump pulley)
Poor revolution of oil pump pulley

Adjust or replace.

2. Tire and wheel

Improper tire out of specifications⁽¹⁾
Improper wheel out of specifications⁽¹⁾
Tires not properly inflated

Replace or reinflate.

3. Fluid

Low fluid level
Air entry in fluid
Dust entry in fluid
Fluid deterioration
Inadequate warm-up of fluid ⁽²⁾

Refill, bleed air, replace or instruct customer.

4. Idle speed

Lower idle speed
Excessive drop of idle speed at start or when turning the steering wheel ⁽³⁾

Adjust or instruct customer.

5. Measure the hydraulic pressure. <Ref. to INSPECTION , Oil Pump.>

Replace the problem parts.

6. Measure the steering wheel effort. <Ref. to MEASUREMENT OF STEERING EFFORT , INSPECTION, General Diagnostic Table.>

Adjust or replace.

Vehicle leads to one side or the other.
Returning force of steering wheel to center is poor.
Steering wheel vibrates when turning.

1. Fluid line

Folded hose
Flattened pipe

Correct or replace.

2. Tire and wheel

Flat tire
Mixed use of different tires
Mixed use of different wheels
Abnormal wear of tire
Unequal tread remaining
Unequal pressure of tire

Adjust, fix or replace.

3. Front alignment

Improper or unequal caster
Improper or unequal toe-in
Loose suspension connections

Adjust or retighten.

4. Others

Damaged joint assembly
Unbalanced height
Unbalanced weight

Replace, adjust or instruct customer.

5. Measure the steering wheel effort. <Ref. to MEASUREMENT OF STEERING EFFORT , INSPECTION, General Diagnostic Table.>

Adjust or replace.

⁽¹⁾

If the tires or wheels are wider than standard, the load to the power steering system is increased. Accordingly, in a condition, for example before fluid warms-up, relief valve may work before reaching maximum turning angle. In this case, steering effort may be heavy. When the measured hydraulic pressure is normal, there is no abnormal thing.

⁽²⁾	In cold weather, steering effort may be heavy due to increased flow resistance of cold fluid. After warming-up engine, turn the steering wheel from stop to stop several times to warm-up fluid. If steering effort reduces normally, function is normal.

⁽³⁾	In cold weather or with insufficient warm-up of the engine, steering effort may be heavy due to excessive drop of idle rpm when turning the steering wheel. In this case, start the vehicle with increasing engine speed than usual. If steering effort reduces normally, function is normal.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

General Diagnostic Table: Inspection: Notes

Use the Manual With the Right Hardware

When to See a Mechanic

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