ASE Steering & Wheel Alignment Flashcards

What is the function of the Electronic Power Steering (EPS) torque sensor?

Answer: Detects how much force the driver is applying to the steering wheel to determine assist

The EPS torque sensor measures torsional twist in the steering column to determine driver input force, which the ECM uses to calculate the appropriate assist level.

When replacing a rack and pinion steering gear, what is a critical step to ensure proper steering wheel centering?

Answer: Center the rack before installation and verify steering wheel is centered before adjusting toe

Centering the rack before installation ensures the steering wheel can be centered after toe adjustment without running out of tie rod adjustment range.

Which power steering system component prevents excessively high hydraulic pressure that could damage hoses or the steering gear?

Answer: Pressure relief valve

The pressure relief valve inside the power steering pump limits maximum hydraulic pressure, typically to 1,200–1,500 psi, to protect system components.

A vehicle with four-wheel independent suspension dog-tracks on the highway. What alignment correction should the technician make FIRST?

Answer: Correct the rear toe and thrust angle

Dog-tracking is caused by a non-zero thrust angle; correcting rear toe to align the thrust line with the vehicle centerline eliminates the condition.

What is the purpose of the steering dampener (steering stabilizer) found on many trucks and SUVs with solid front axles?

Answer: Absorbs road-induced shimmy and vibration transmitted through the steering linkage

A steering stabilizer is essentially a horizontal shock absorber mounted across the steering linkage to dampen shimmy and bump steer impulses.

Which condition describes bump steer?

Answer: Unintended toe change that occurs as the suspension travels through its range of motion

Bump steer occurs when the tie rod arc does not match the control arm arc through suspension travel, causing toe to change without driver input.