Pinpoint Tests
Suspension System
Pinpoint Tests
Pinpoint Test A: Vehicle Drifts/Pulls
This pinpoint test is intended to diagnose the following:
- Unevenly loaded vehicle
- Tire pressure
- Tire forces
- Brake drag
- Incorrect vehicle alignment
- Steering system
PINPOINT TEST A: VEHICLE DRIFTS/PULLS
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A1 CHECK FOR UNEVENLY LOADED VEHICLE
- Visually check the vehicle for an uneven loading condition.
- Is the vehicle unevenly loaded?
Yes
ADVISE the customer of uneven loading condition.
No
GO to A2.
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A2 CHECK THE TIRE PRESSURES AND TIRE CONDITIONS
- Check the tire pressures. Refer to the Vehicle Certification (VC) label located on the driver door jamb. Check the tires for uneven/abnormal wear. Refer to Diagnosis and Testing-Wheels and Tires in Wheels and Tires Testing and Inspection.
- Are the tire pressures and tire conditions OK?
Yes
GO to A3.
No
ADJUST the tire pressures to the specified pressure or INSTALL new tires as necessary.
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A3 ISOLATE TIRE DRIFT/PULL CONDITION
- NOTE: It is important to determine if tire forces are the cause of a drift/pull condition. Changing the position of the wheel and tire assemblies on the vehicle may correct a pull/drift condition, however the tire drift/pull may return if the wheel and tire assemblies are repositioned during future service. A tire or tires that are causing a drift/pull should not be removed from service unless it has been determined that the tire(s) are worn beyond specification. Refer to Diagnosis and Testing - Wheels and Tires in Wheels and Tires Testing and Inspection.
- Cross the front wheel and tire assemblies from left-to-right. Refer to Wheels and Tires Removal and Replacement.
- Does the vehicle drift/pull?
Yes
If the vehicle drifts/pulls in the opposite direction, tire forces are causing the drift/pull. ROTATE the wheel and tire assemblies from front-to-rear. REFER to Wheels and Tires Removal and Replacement. If the vehicle drifts/pulls in the same direction, GO to A4.
No
Tire forces were causing the drift/pull and the concern has been corrected.
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A4 CHECK FOR BRAKE DRAG
- Spin all 4 wheel and tire assemblies by hand and check for brake drag.
- Do the wheels spin freely?
Yes
GO to A5.
No
REFER to Brake System - General Information Symptom Related Diagnostic Procedures to diagnose brake drag condition.
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A5 CHECK THE WHEEL ALIGNMENT
- Using alignment equipment and the manufacturer's instructions, check the wheel alignment.
- Is the wheel alignment out of specification?
Yes
ADJUST the alignment as necessary. REFER to General Procedures.
No
REFER to Steering System - Electronic Power Assist Steering (EPAS) Special Tool(s) Used With Diagnostics to diagnose steering system drift/pull/wander condition.
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