GMC chevrolet camaro 2000 Service Manual page 95

0-84 Vibration Diagnosis and Correction
Auto Mode
Auto Mode considers the suspected source of vibration
in conjunction with the vehicle's baseline data to
identify a suspected source of vibration.
1. Select AUTO MODE from the EV A main menu.
The EVA will ask to select the suspected source·
of vibration as ENGINE RPM or VEHICLE SPEED.
• If engine RPM is selected, move the cursor to
the correct number of engine cylinders then
press ENTER. Using the EVA keypad,
enter the engine RPM (500-6000 RPM) where
the vibration occurs at a maximum level.
" If vehicle speed is selected, enter the tire size
information with one of the following
three options:
- RPS at 5 mph - Look up the revolutions
per second (RPS) for specific tire size.
- Database - Select tire type and tire size
from each selection screen.
- Manual Entry - Select Manual Entry when
the vehicle is fitted with specialty tires.
2. Enter one of the following driveshaft
configurations:
• FWD (Front Wheel Drive)
• RWD (Rear Wheel Drive)
• AWD (All Wheel Drive)
• 4WD (Four Wheel Drive)
3. Enter the axle ratio only if FWD is not selected.
4. Select the vehicle speed units in
mph (miles-per-hour) or
km/h (kilometers-per-hour).
Smart Strobe
The Smart Strobe mode enables complete control of
the frequency at which the strobe light will flash. Smart
Strobe is well suited for identifying the speed at which
objects are rotating at. This is helpful for identifying the
source of a vibration. The pulley RPM can be converted
to a frequency by pressing the RPM/Hz key.
1. To use the Smart Strobe function, begin by
clipping the inductive pickup of the timing
light to the "wiring loop" of the EV A.
2. Connect to a 12-volt power source.
3. If a timing light with an advance feature is used,
set advance to O degrees.
4. From the Main Menu, select Smart Strobe.
5. With the engine off, mark the object you suspect
is causing vibration. A dab of white paint or
correction fluid works well.
6. Enter an initial test point strobe frequency
between 10-200 Hz (600-12000 RPM).
7. Run the engine at the RPM at which the vibration
is the greatest and trigger the strobe.
8. As you point the strobe light at the spinning
object, press the Strobe Light trigger.
General Information
9. Press the EVA up or down keys to manually
adjust the RPM until only one mark is seen
and the mark on the object appears stationary.
i 0. As the test is run, the strobe speed must be
manually adjusted to match the actual object RPM.
EVA Calibration
The EV A features the following two built-in calibration
procedures:
• Sensor calibration
" Phase shift calibration
Calibrate a replaced or an added sensor in order to
function properly with the EV A unit. The phase
shift calibration is performed at the factory. Do NOT
repeat this calibration under normal use.
Sensor Calibration
1. Lay the sensor on a flat stationary surface with
the UP side facing upward.
2. Plug the sensor into either input A or B.
3. Plug the EVA into a 12-volt power supply.
4. After the display initializes, select the. proper input.
5. Press the number 1 to initiate sensor calibration.
6. Press the number 2 three times on the keypad.
The message BURNING will appear, followed
by a request to turn the sensor over.
7. Turn the sensor over.
8. Press any key in order to commence calibration:
" Calibration will take approximately 20 seconds.
s
The display will return to the active mode
when calibration is complete.
Phase Shift Calibration
i. Plug the EVA into a 12-volt power supply.
2. Press the number 5 to initiate phase shift
calibration.
3. Press the number 2 on the keypad three times in
order to begin calibration:
O
Do not press any key until the message ANY
KEY TO CONTINUE appears. Pressing a
key will cancel the calibration process.
" The display will flash numbers for 5-6 minutes.
(If the numbers flash for more than 10 minutes,
the EVA is defective.)
" The message BURNING PHASE SHIFT
CONST ANTS will appear for one minute.
" The BURNING CENTER FREQUENCIES
LOW=40, MEDIUM=50, HIGH=60 message will
appear.
e
The ANY KEY TO CONTINUE message
should appear.
4. Press any key in order to return to the
active mode.
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