Pinpoint Test H: Steering System Pull, Drift Or Wander

Description 

• The EPAS system is designed to compensate for some steering issues (drift, pull, wander, etc.). However, if the steering issue is severe enough, the condition or symptom may become noticeable to the driver.
• The system starts compensating when vehicle speed exceeds 40 km/h (25 mph) and the vehicle is traveling straight. The system compensates on any road crown condition; however, some amount of pull is present during, and shortly after, quick lane transitions. After driving straight on a constant road crown with both hands on the steering wheel for at least 45 seconds, the pull condition can be assessed. The system does not compensate when turning at low speeds. For the system to compensate, the driver's hands must remain on the steering wheel.
• Drift describes what a vehicle with this condition does with the hands off the steering wheel.
• Pull is described as a tugging sensation on the steering wheel felt by the driver, which must be overcome to keep the vehicle going straight.
• Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road.

Pinpoint Test Applicability 

• This test applies to the following diagnostic concerns:
• This test applies to steering drift, pull, or wander only.

This test DOES NOT apply to noise, binding, sticking, returnability, off-center, or steering wheel play concerns.

Symptom Definition 

• Pull occurs when the vehicle feels like it is consistently pulling to the right, or consistently pulling to the left. Vehicle tends to want to pull or drift to one side but not both sides of the vehicle.
• Drift is the tendency of the vehicle to drift from the intended path with hands off steering wheel.
• Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down flat smooth roads.

Pinpoint Test Purpose 

• The purpose of this pinpoint test is to evaluate if steering drift, pull, or wander is occurring. This test will determine if the concern is caused by the steering system. This does not address Steering Wheel Off Center concerns, for which the steering wheel is at an angle when driving straight on a level road.

Possible Sources 

• Alignment
• Tire(s)
• Steering gear mounts
• Steering column shaft U-joints
• Steering column
• Suspension components
• Steering gear

1. NOTE: This procedure must be completed using FDRS. Do not clear DTCs until the FDRS procedure has completed.To complete the diagnosis, navigate to the FDRS Guided Routine tab and carry out the procedure 

   Electronic Power Assist Steering (EPAS) Pulls/Drifts