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1.Check that the operation
sound of the stepper motor can be heard from the EGR valve
when the ignition switch is turned ON (without starting the
engine).
2.If the operation sound cannot be heard,
inspect the drive circuit of the stepper motor.
| note |
If the circuit is normal,
either the stepper motor or the engine-ECU
<M/T>
or engine-A/T-ECU <A/T>
may have failed.
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1.Remove the EGR
valve.
2.Measure the resistance between terminal
No. 2 and either terminal No. 1 or terminal No. 3 of the
connector at the EGR valve.
Standard value: 20
-
24 Ω
(at 20°C)
3.Measure the resistance
between terminal No. 5 and either terminal No. 6 or terminal
No. 4 of the connector at the EGR
valve.
Standard value: 20 -
24 Ω
(at 20°C)
Using a new gasket, install the
EGR valve by tightening its mounting bolts to the specified
torque.
Tightening Torque: 24 ±
4 N·m
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1.Remove the EGR
valve.
2.Attach a test wiring harness (special
tool MB991658) to the connector at the EGR valve.
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3.
| caution |
Connecting battery voltage to
the EGR valve for a long term could damage the
coil.
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Connect the positive (+) terminal of the
battery to terminal No. 2.
4.Connect terminals No.
1 and No. 3 to the negative (-) terminal of the battery, in
order to test whether the stepper motor vibrates (with a
slight shudder), indicating that the stepper motor is
operating.
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5.
| caution |
Connecting battery voltage to
the EGR valve for a long term could damage the
coil.
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Connect the positive (+) terminal of the
battery to terminal No. 5.
6.Connect terminals No.
4 and No. 6 to the negative (-) terminal of the battery, in
order to test whether the stepper motor vibrates (with a
slight shudder), indicating that the stepper motor is
operating.
7.If a vibration can be felt during the
test, the stepper motor is normal.
8.Using a new
gasket, install the EGR valve by tightening its mounting
bolts to the specified torque.
Tightening
torque: 24 ±
3 N·m
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1.
| caution |
Do not use a solvent or
detergent, which could enter the motor and cause
it to malfunction.
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Remove the EGR valve and check that the EGR valve is
not stuck or clogged with carbon deposits. Use a wire brush
to clean the valve if necessary.
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2. Using a new gasket,
install the EGR valve by tightening its mounting bolts to
the specified torque.
Tightening torque: 24
±
3 N·m
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