Captiva |
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• | EL-38792-A Electronic Vibration Analyzer |
• | EL-38792-VS Vibrate Software |
For equivalent regional tools, refer to Special Tools and Equipment .
The numbers below refer to the step numbers on the diagnostic table.
Obtaining rotational speed for the components rotating at tyre/wheel speed is critical to systematically eliminating specific vehicle component groups. These component rotational speeds can be generated by using the EL-38792-VS Vibrate Software, or through calculating them manually.
Note: Be certain to OBSERVE for disturbances that match the customer's description FIRST, then look at the EL-38792-A Electronic Vibration Analyser frequency which corresponds with that disturbance.
Proper location of the EL-38792-A Electronic Vibration Analyser, sensor onto the component which is most excited by the vibration disturbance is critical to obtaining an accurate frequency reading.
This test will duplicate virtually any disturbance which occurs while the vehicle is in motion.
Accelerate to a speed high enough above the speed of the disturbance to allow for the time needed to shift into NEUTRAL and for the engine to decrease in RPM to idle speed, before freewheeling down through the disturbance range.
This test will either eliminate or confirm the engine as a contributing cause of the customer concern.
Step | Action | Yes | No | ||||||||||
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Warning: Refer to Road Test Warning in the Preface section. | |||||||||||||
1 | Did you review the Diagnostic Starting Point - Vibration Diagnosis? | Go to Step 2 | |||||||||||
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 tyre and wheel assemblies, steering components and suspension components for any possible faults. Are the tyre 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 tyre and wheel assemblies, steering components, and/or the suspension components before proceeding. Did you correct the faults with the tyre and wheel assemblies, steering components, and/or the suspension components? | Go to Step 5 | Go to Step 3 | ||||||||||
Did you obtain the powertrain ratios for use with the EL-38792-VS Vibrate Software , or calculate the component rotational speeds, if EL-38792-VS Vibrate Software is NOT available? | Go to Step 6 | -- | |||||||||||
6 |
Is the scan tool operating properly? | Go to Step 7 | |||||||||||
7 | Using the EL-38792-A Electronic Vibration Analyser , is the preferred method for gathering necessary vibration frequency data. If the EL-38792-A Electronic Vibration Analyser 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 EL-38792-A Electronic Vibration Analyser available for use? | Go to Step 8 | Go to Step 9 | ||||||||||
8 | Install the EL-38792-A Electronic Vibration Analyser . Is the EL-38792-A Electronic Vibration Analyser 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 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 |
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.
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? | ||||||||||||
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 |
Were you able to duplicate the customer's concern? | Go to Step 17 | |||||||||||
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. Does the disturbance still occur while freewheeling-down in NEUTRAL? | Go to Step 19 | Go to Step 18 | |||||||||||
Does the same disturbance still occur while going the same vehicle speed in a lower gear range? | |||||||||||||
19 | If the EL-38792-A Electronic Vibration Analyser is not available, refer to Symptoms - Vibration Diagnosis and Correction . Did the EL-38792-A Electronic Vibration Analyser detect a dominant frequency? | Go to Step 20 | |||||||||||
20 |
Does the frequency data clearly fall within the tyre/wheel parameters ONLY? | Go to Step 21 | |||||||||||
21 | Does the frequency data clearly fall within the propeller shaft parameters ONLY? | Go to Step 22 | |||||||||||
22 | Is the vehicle equipped with a solid drive axle? |
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