| Subject: | Vehicle Leads/Pulls Characteristics and Diagnosis |
| Models: | 2004-2005 Chevrolet Malibu and Malibu MAXX |
Lead/Pull Description
At a constant highway speed on a typical straight road, lead/pull is the amount
of effort required at the steering wheel to maintain the vehicle's straight path.
Lead/pull is usually caused by the following factors:
| | Variability in the tire construction may
produce lead/pull. The rear tires will not cause lead/pull. |
| • | Unbalanced steering gear |
Visual/Physical Inspection
| • | Inspect for aftermarket devices which could affect the operation of any
of the suspension subsystems. |
| • | Inspect the easily accessible or visible system components for obvious
damage or conditions which could cause the symptom. |
| • | Inspect for proper tire size and inflation pressure. Refer to Tire Placard
in General Information, SI Document ID #1211368. |
| • | Inspect for abnormal tire wear. |
Vehicle Leads/Pulls Alignment Diagnosis and Repair
Front cross-caster and front cross-camber are the only wheel alignment parameters
that influence lead or pull.
For vehicle leads/pulls diagnosis, refer to Vehicle Leads/Pulls, SI Document
ID #1458799.
If the vehicle leads/pulls to the left after performing the steps listed in
SI Document ID 1458799 and the front wheel alignment parameters are found to
be in specification, adjust the front left and/or right camber to achieve a cross-camber
of -0.50° to -0.75°. Refer to Front Camber Adjustment, SI Document ID 1238715.
The cross-camber is the difference between the left side camber and the right side
camber (cross-camber = LH camber-RH camber). Positive cross-camber may cause
the vehicle to pull to the left. For example: If the vehicle pulls to the left, adjust
the cross-camber more negative and vice-versa.
Steering Position and Torque Sensor Calibration
Important: ONLY perform the steering position sensor
and torque sensor recalibration procedure after the tires, suspension and alignment
specifications have been inspected and/or corrected and the vehicle still exhibits
a lead or pull condition. Failure to do so may result in additional customer lead
and or pull concerns.
After inspecting the suspension, tires and alignment, and if the vehicle still
leads or/pulls, it may be necessary to recalibrate the steering position sensor and
torque sensor. Refer to Control Module Setup, SI Document ID #1255331.
