|
Step
|
Action
|
Yes
|
No
|
|
Refer to
Road Test Warning
.
|
1
|
Did you review the Diagnostic Starting Point - Vibration Diagnosis?
|
Go to
Step 2
|
Go to
Diagnostic Starting Point - Vehicle
|
2
|
Did the customer concern indicate that the vibration occurs ONLY while the vehicle is standing still?
|
Go to
Step 6
|
Go to
Step 3
|
3
|
Visually inspect the tire and wheel assemblies, steering components and suspension components for any possible faults.
Are the tire and wheel assemblies, steering components and suspension components in good working condition?
|
Go to
Step 5
|
Go to
Step 4
|
4
|
|
Note
|
|
Do NOT operate the vehicle until the faults are corrected.
|
Correct the faults with the tire and wheel assemblies, steering components, and/or the suspension components before proceeding .
Did you correct the faults with the tire and wheel assemblies, steering components, and/or the suspension components?
|
Go to
Step 5
|
Go to
Step 3
|
5
|
|
1.
|
Obtain the drive axle final drive ratio.
|
|
2.
|
If the
GE-38792-VS
software , IS available, obtain the transmission gear ratios.
|
|
3.
|
If the
GE-38792-VS
software is NOT available, take note of the tire size on each axle, then calculate the tire rotational speed for each size tire used and calculate the propeller shaft rotational speed, if equipped. Refer to
Component Rotational Speed Calculation
.
|
Did you obtain the powertrain ratios for use with the
GE-38792-VS
software , or calculate the component rotational speeds, if
GEJ-38792-VS
software is NOT available?
|
Go to
Step 6
|
-
|
6
|
|
2.
|
With the scan tool, bring up the Powertrain Control Module data list and select Engine Speed.
|
Is the scan tool operating properly?
|
Go to
Step 7
|
Go to
Diagnostic System Check - Vehicle
|
7
|
Using the
GE-38792-A
EVA 2 , is the preferred method for gathering necessary vibration frequency data.
If the
GE-38792-A
EVA 2 is not available, the necessary vibration frequency data will have to be obtained based on symptoms observed during testing. Review
Symptoms - Vibration Diagnosis and Correction
to become familiar with the possible frequency ranges. Review Symptoms - Vibration Diagnosis and Correction, as necessary throughout the remainder of diagnostics.
Is the
GE-38792-A
EVA 2 available for use?
|
Go to
Step 8
|
Go to
Step 9
|
8
|
Install the
GE-38792-A
EVA 2 .
Is the
GE-38792-A
EVA 2 operating properly?
|
Go to
Step 9
|
Go to
Electronic Vibration Analyzer (EVA) Description and Operation
|
9
|
Did the customer concern indicate that the vibration occurs ONLY while the vehicle is standing still?
|
Go to
Vibration Analysis - Engine
|
Go to
Step 10
|
10
|
Did the customer concern indicate that the vibration occurs ONLY during heavy acceleration at launch?
|
Go to
Step 11
|
Go to
Step 14
|
11
|
|
1.
|
Install the
GE-38792-A
EVA 2 sensor, if available, to the pinion area of the drive axle. Route the sensor lead wire clear of rotating parts and loosely secure the wire clear of moving parts. If it is not possible to install the
GE-38792-A
EVA 2 sensor, if available, to the drive axle, install the sensor to an exposed portion of the floor panel or seat track in the area that the customer noted is most respondent to the vibration.
|
|
2.
|
Select a smooth, level road.
|
|
3.
|
With the vehicle at a stand-still, apply the regular brake and place the transmission in the lowest forward gear.
|
|
4.
|
|
Note
|
|
Do not accelerate to the point of causing the drive wheels to squeal, slip or hop. This would obscure the results of the test.
|
Release the regular brakes and accelerate aggressively to 32 km/h (20 mph).
|
|
5.
|
Observe the vehicle for disturbances that match the customer's description and note the following conditions:
|
|
|
•
|
The vibration frequency reading, if detected by the
GE-38792-A
EVA
|
|
|
•
|
The feel and/or sound of the disturbance
|
|
6.
|
If a reading could not be obtained by the
GE-38792-A
EVA 2 , move the
GE-38792-A
EVA 2 sensor, if available, to another part that is respondent to the vibration and repeat steps 3-5.
|
Were you able to duplicate the customer's concern?
|
Go to
Step 12
|
Go to
Step 14
|
12
|
Is the vehicle primary driveline configuration rear wheel drive?
|
Go to
Step 13
|
Go to
Step 14
|
13
|
Is the vehicle equipped with a solid drive axle?
|
Go to
Vibration Analysis - Driveline
|
Go to
Vibration Analysis - Hub and/or Axle Input
|
14
|
|
1.
|
Install the
GE-38792-A
EVA 2 sensor, if available, to the component identified by the customer as most respondent to the vibration. If no component was identified, install the
GE-38792-A
EVA 2 sensor, if available, to the steering column. You may have to move the sensor to other locations later.
|
|
2.
|
Select a smooth, level road and slowly accelerate the vehicle up to highway speed.
|
|
3.
|
Observe the vehicle for disturbances that match the customer's description and note the following conditions:
|
|
|
•
|
The transmission gear range and the specific gear
|
|
|
•
|
The vibration frequency reading, if detected by the
GE-38792-A
EVA 2
|
|
|
•
|
The feel and/or sound of the disturbance
|
|
4.
|
If the vibration seems to excite a particular component of the vehicle more than the steering column, then move the
GE-38792-A
EVA 2 sensor, if available, onto that component and repeat steps 2 and 3.
|
Were you able to duplicate the customer's concern?
|
Go to
Step 17
|
Go to
Step 15
|
15
|
Is the vehicle equipped with selectable four-wheel or all-wheel drive?
|
Go to
Step 16
|
Go to
Step 17
|
16
|
|
1.
|
With the
GE-38792-A
EVA 2 sensor still installed in the same position, activate/engage all-wheel drive.
|
|
2.
|
Select a smooth, level road and slowly accelerate the vehicle up to highway speed.
|
|
3.
|
Observe the vehicle for disturbances that match the customer's description and note the following conditions:
|
|
|
•
|
The transmission gear range and the specific gear
|
|
|
•
|
The vibration frequency reading, if detected by the
GE-38792-A
EVA 2
|
|
|
•
|
The feel and/or sound of the disturbance
|
|
4.
|
If the vibration seems to excite a particular component of the vehicle more than the steering column, then move the
GE-38792-A
EVA 2 sensor, if available, onto that component and repeat steps 2 and 3.
|
Were you able to duplicate the customer's concern?
|
Go to
Step 17
|
Go to
Vibration Diagnostic Aids
|
17
|
|
1.
|
Accelerate the vehicle to a speed higher than the speed at which the disturbance occurs.
|
|
2.
|
|
Note
|
|
If the vehicle is equipped with a continuously variable type automatic transmission, let the vehicle coast to a stop before shifting back into gear.
|
Shift the vehicle into NEUTRAL and allow the vehicle to coast down through the disturbance range.
|
Does the disturbance still occur while coasting-down in NEUTRAL?
|
Go to
Step 19
|
Go to
Step 18
|
18
|
|
1.
|
Select a smooth, level road and slowly accelerate the vehicle up to the speed at which the disturbance occurs.
|
|
2.
|
Decelerate and safely downshift by one gear range.
|
|
3.
|
Operate the vehicle at the same VEHICLE SPEED at which the disturbance occurs.
|
Does the same disturbance still occur while going the same vehicle speed in a lower gear range?
|
Go to
Vibration Analysis - Hub and/or Axle Input
|
Go to
Vibration Analysis - Engine
|
19
|
If the
GE-38792-A
EVA 2 is not available, refer to
Symptoms - Vibration Diagnosis and Correction
.
Did the
GE-38792-A
EVA 2 detect a dominant frequency?
|
Go to
Step 20
|
Go to
Symptoms - Vibration Diagnosis and Correction
|
20
|
|
1.
|
If the
GE-38792-VS
software IS available, use the drive axle final drive ratio, the specific transmission gear ratio, and the engine RPM to make a comparison to the dominant frequency reading recorded.
|
|
2.
|
If the
GE-38792-VS
software is NOT available, compare the dominant frequency reading recorded to the component rotational data which you calculated previously.
|
Does the frequency data clearly fall within the tire/wheel parameters ONLY?
|
Go to
Vibration Analysis - Tire and Wheel
|
Go to
Step 21
|
21
|
Does the frequency data clearly fall within the propeller shaft parameters ONLY?
|
Go to
Vibration Analysis - Driveline
|
Go to
Step 22
|
22
|
Is the vehicle equipped with a solid drive axle?
|
Go to
Symptoms - Vibration Diagnosis and Correction
|
Go to
Vibration Analysis - Hub and/or Axle Input
|
