(3) Consider visual inspection as part of the initial inspection procedure and note any conditions that appear to be abnormal.Record the tire pressures, but do not adjust them first.Record leaking fluid, loose nuts and bolts, or traces of possible rubbing between components to bright spots.Check the loading space for unusual loads. (4) Carry out the road test and duplicate the condition several times in the road test for confirmation.
(5) Perform a road test quick check immediately after the condition has reappeared.This will help to find the correct diagnostic procedure.Perform more than one quick road test check to confirm that the results are correct.Remember, road test quick checks may not tell you where the problem is, but they can tell you that the problem is not there. 1.1.5.2.3.6 Road test quick check (1)24~80km/h ： Slight acceleration, a whimper is heard and the front floor may also vibrate.It is particularly obvious when accelerating at a specific motor speed.It also makes a whimper, depending on the component that causes the noise.Refer to whimpering in the symptom chart. (1) Acceleration / deceleration:
When accelerating and decelerating slowly, you may feel shaking at the steering wheel / pillar, seat, front floor panel, front door trim panel or front sheet metal.It is a low-frequency vibration (the period is about 9-15 times per second).It sometimes increases with a slight brake application.Refer to idle rumble / shake / vibration in the symptom table. (2) High speed:
An invisible vibration is felt on the front floor or seat, but accompanied by sound or rumble or hum.When the gear is in neutral and the motor is coasting at idle speed.If the vibration is still felt, it may be the wheel, tire, front brake disc, wheel hub or front axle.Please refer to shaking and shaking during driving in the symptom table. (3) Motor speed sensitivity: When the motor reaches a certain speed, vibration will be felt.It will disappear when coasting in neutral.This vibration is more obvious when the vehicle is stationary and operates the motor at the speed at which it failed. It may be caused by any component.Refer to shaking and shaking while driving in the symptom table.
(4) The noise and vibration (click, slap or friction) during steering may be caused by the following reasons: The front wheel bearing is worn, damaged or improperly installed. Powertrain / driveline mount damaged.
1.1.5.2.3.7 Road conditions Any experienced technician will choose a road test route for NVH diagnosis.The road chosen should be fairly flat and free from ups and downs (unless special conditions are to be identified).It is best to have a flat asphalt road that can be driven at different speeds.Gravel or rough roads are not suitable because of additional road noise.Once the route is established and used frequently, the road noise variables can be eliminated from the test results. Note: some problems only occur on flat asphalt roads.
If a customer complains that noise or vibration occurs only on a particular road, the cause may be the road surface.If possible, the vehicle can be tested on the same type of road. 1.1.5.2.3.8 Vehicle preparation Perform a thorough visual inspection of the vehicle before performing the road test.Record any condition that appears to be abnormal.Do not perform any repairs or adjustments until the road test is complete, unless the vehicle is inoperable or the condition may cause injury to technicians. After confirming the condition and repairing, be sure to replace all removed parts. 27