Kia Optima: Engine Control System / Variable Charge Motion Actuator (VCMA)
Description and operation
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The Variable Charge Motion Actuator (VCMA) is installed on the inlet
of the intake manifold.
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It consists of a DC motor which actuates the VCM valve and a position
sensor which detects the position of the VCM valve.
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The VCM system tumbles air flow entering into combustion chamber of each
cylinder by closing the VCM valve in the cold start conditions.
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This tumble effect reduces cold start emissions by improving atomization
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Components and components location

1. Variable Charge Motion Actuator
(VCMA)
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Schematic diagrams

Harness Connector

Repair procedures
1. |
The engine control system can be more quickly diagnosed for troubles
by using the vehicle diagnostic system (KDS). (Refer to "DTC guide")
KDS provides the following information.
(1) |
Self diagnosis : Inspects and displays diagnostic trouble code
(DTC)
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(2) |
Sensor data : Checks the system input/output value status
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(3) |
Forced operation : Checks the system operating status
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(4) |
Additional function : Controls system options, zero point adjustment
and other functions
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1. |
Disconnect the negative battery terminal.
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2. |
Disconnect the PCV hose (A).

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3. |
Disconnect the VCMA connector (A).
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4. |
Remove the VCMA mounting bolts (B).
Tightening torque :
9.8 - 11.8 N·m (1.0 - 1.2 kgf·m, 7.2 - 8.7 lb·ft)
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5. |
Remove the VCMA (A).

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Install the component with the specified torque.
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Note that internal damage may occur when the component is dropped.
In this case, use it after inspecting.
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The VCM actuator has to be installed at the fully closing positon
of the VCM valve.
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If it doesn't, the VCM coupling of the VCM shaft can't be put
in the VCM actuator.
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1. |
Install in the reverse order of removal.
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Specifications
Specification
Item
Specification
Coil resistance (Ω)
30.0 - 35.0 [22°C (71.6°F)]
Description and op ...
Fuel pressure test
Fuel Pressure Test
1.
Release the residual pressure in fuel line.
(Refer to Fuel Delivery System - "Release Residual Pressure in Fuel Line") ...
Other information:
Repair procedures
Removal
Interior Antenna 1
1.
Disconnect the negative battery terminal.
2.
Remove the surround view monitor (SVM) unit.
(Refer to Advanced Driver Assistance System (ADAS) - "Surround View Monitor
(SVM) Unit")
...
Specifications
Specification
Manifold Absolute Pressure Sensor (MAPS)
Pressure
Output Voltage (V)
kPa
kgf/cm²
psi
20
0.2
2.9
0.79
46. ...