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1.Check that the operation sound of the stepper motor can be heard from the exhaust gas
recirculation 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.
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If the circuit is normal, either the stepper motor or the engine-ECU may have failed.
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1.Remove the exhaust gas recirculation valve.
2.Measure the resistance between terminal No. 2 and either terminal No. 1 or terminal
No. 3 of the connector at the exhaust gas recirculation 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 exhaust gas recirculation valve.
Standard value: 20 - 24 Ω (at 20°C)
Using a new gasket, install the exhaust gas recirculation valve by tightening its mounting
bolts to the specified torque.
Tightening Torque:
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1.Remove the exhaust gas recirculation valve.
2.Attach a test wiring harness (special tool MB991658) to the connector at the exhaust
gas recirculation valve.
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3.
| caution |
Connecting battery voltage to the exhaust gas recirculation 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 exhaust gas recirculation 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 exhaust gas recirculation valve by tightening its
mounting bolts to the specified torque.
Tightening Torque:
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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 exhaust gas recirculation valve and check that the exhaust gas recirculation
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 exhaust gas recirculation valve by tightening its
mounting bolts to the specified torque.
Tightening Torque:
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