Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Lexus IS FFACTORY OEM SERVICE PROCEDURE
Problem Symptoms Table
HINT.
- Use the following table to help determine the cause of a problem. The likely causes of the problem are indicated in descending order. Check each suspected area in order. Repair or replace faulty parts or perform adjustments as necessary.
- Inspect the fuses and relays related to this system before inspecting the suspected areas below.
Power Steering System
PROBLEM SYMPTOMS CHART - POWER STEERING SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| Steering is heavy | Front tires (Improperly inflated, unevenly worn) | INSPECTION |
| Front wheel alignment (Incorrect) | FRONT WHEEL ALIGNMENT | |
| Front suspension (Lower ball joint) | REMOVAL | |
| Power steering gear assembly | REMOVAL | |
| Steering column assembly | REMOVAL | |
| Torque sensor (Built into steering gear assembly) | DTC C1511 TORQUE SENSOR CIRCUIT MALFUNCTION | |
| Power steering motor | REMOVAL | |
| Speed sensor | TEST MODE PROCEDURE | |
| Skid control ECU | REMOVAL | |
| Battery and power source system | - | |
| Power steering ECU power source voltage and relay | DTC C1552 PIG POWER SUPPLY VOLTAGE MALFUNCTION | |
| Power steering ECU assembly | POWER STEERING ECU | |
| Steering effort differs between right and left or is uneven | Calibration of turning angle sensor output and torque sensor | CALIBRATION |
| Front tires (Improperly inflated, unevenly worn) | INSPECTION | |
| Front wheel alignment (Incorrect) | FRONT WHEEL ALIGNMENT | |
| Front suspension (Lower ball joint) | REMOVAL | |
| Power steering gear | REMOVAL | |
| Torque sensor (Built into steering link assembly) | DTC C1511 TORQUE SENSOR CIRCUIT MALFUNCTION | |
| Steering column assembly | REMOVAL | |
| Power steering motor | REMOVAL | |
| Power steering ECU assembly | POWER STEERING ECU | |
| While driving, steering effort does not change in accordance with vehicle speed or the steering wheel does not return properly | Front suspension (Lower ball joint) | REMOVAL |
| Speed sensor | TEST MODE PROCEDURE | |
| Skid control ECU | REMOVAL | |
| Combination meter | REMOVAL | |
| Torque sensor (Built into steering gear assembly) | DTC C1511 TORQUE SENSOR CIRCUIT MALFUNCTION | |
| Power steering motor | REMOVAL | |
| Power steering gear assembly | REMOVAL | |
| Power steering ECU assembly | POWER STEERING ECU | |
| A knocking (or cranking) sound occurs when turning the steering wheel back and forth while power steering is in operation | Front suspension (Lower ball joint) | REMOVAL |
| Steering intermediate shaft | REMOVAL | |
| Power steering gear | REMOVAL | |
| Noise occurs when turning the steering wheel during low speed driving | Power steering gear | REMOVAL |
| Steering column assembly | REMOVAL | |
| Power steering ECU assembly | POWER STEERING ECU | |
| High-pitched sounds (squeaking) occur when turning the steering wheel slowly with the stepped | Power steering gear assembly | REMOVAL |
| Power steering motor | REMOVAL | |
| The steering wheel vibrates and noise occurs when turning the steering wheel from lock to lock | Power steering gear assembly | REMOVAL |
| Steering column assembly | REMOVAL | |
| P/S warning light remains on | PS warning light remains on | PS WARNING LIGHT REMAINS ON |
| P/S warning light does not come on | PS warning light does not come on | PS WARNING LIGHT DOES NOT COME ON |
Factory Service Tools
Use the Manual With the Right Hardware
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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.