Hyundai Accent: Engine Control / Fuel System / Engine Control System

Components and Components Location ➤

Description and Operation ➤

Engine Control Module (ECM) ➤

Mass Air Flow Sensor (MAFS)

- Description MAFS uses a hot-film type sensing element to measure the mass of intake air entering the engine, and send the signal to ECM.A large amount of intake air represents acceleration or high load conditions while a small amount of intake air represents deceleration or idle. The ECM uses this information to control the EGR solenoid valve and correct the fuel amount.

1.Check the MAFS visually.

– Mounting direction correct.

– Any contamination, corrosion or damage on connector.

– Air cleaner's clogging or wet.

– MAFS cylinder's deforming or blocking by any foreign material.

2.Check any leakage on intake system and intercooler system.

1.Turn the ignition switch OFF and disconnect the battery (-) cable.

2.Disconnect the MAFS connector (A).

3.Remove the clamp (B).

4.Remove the installation bolts and then remove the MAFS (C).

Mass air flow sensor clamp installation bolt :2.9 - 4.9 N.m (0.3 - 0.5 kgf.m, 2.2 - 3.6 lb-ft)Mass air flow sensor installation bolt :2.9 - 4.9 N.m (0.3 - 0.5 kgf.m, 2.2 - 3.6 lb-ft)

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.

• Be careful not to damage the sensing element and the honey cell.

1.Install in the reverse order of removal.

ETC (Electronic Throttle control) System ➤

Manifold Absolute Pressure Sensor (MAPS)

- Description Manifold Absolute Pressure Sensor (MAPS) is a speed-density type sensor and is installed on the surge tank. It senses absolute pressure of the surge tank and transfers the analog signal proportional to the pressure to the ECM. By using this signal, the ECM calculates the intake air quantity and engine speed.The MAPS consists of a piezo-electric element and a hybrid IC amplifying the element output signal. The element is silicon diaphragm type and adapts pressure sensitive variable resistor effect of semi-conductor. Because 100% vacuum and the manifold pressure apply to both sides of the sensor respectively, this sensor can output analog signal by using the silicon variation proportional to pressure change.

1.Connect a GDS on Data Link Connector (DLC).

2.Check MAPS output voltage at idle and IG ON.

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Disconnect the manifold absolute pressure sensor connector (A).

3.Remove the installation bolt (B), and then remove the sensor from the surge tank.

Manifold absolute pressure sensor installation bolt :6.9 ~ 8.8 N.m (0.7 ~ 0.9 kgf.m, 5.1 ~ 6.5 lb-ft)

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.

• Insert the sensor in the installation hole and be careful not to damage when installation.

1.Install in the reverse order of removal.

Intake Air Temperature Sensor (IATS)

- Specification

1.Turn ignition switch OFF.

2.Disconnect IATS connector.

3.Measure resistance between IATS terminals 3 and 4.

4.Check that the resistance is within the specification.

Specification : Refer to "Specification"

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Disconnect the manifold absolute pressure sensor connector (A).

3.Remove the installation bolt (B), and then remove the sensor from the surge tank.

Manifold absolute pressure sensor installation bolt :6.9 ~ 8.8 N.m (0.7 ~ 0.9 kgf.m, 5.1 ~ 6.5 lb-ft)

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.

• Insert the sensor in the installation hole and be careful not to damage when installation.

1.Install in the reverse order of removal.

Engine Coolant Temperature Sensor (ECTS) ➤

Crankshaft Position Sensor (CKPS)

- Description Crankshaft Position Sensor (CKPS) detects the crankshaft position and is one of the most important sensors of the engine control system. If there is no CKPS signal input, fuel is not supplied.That is, vehicle can't run without CKPS signal. This sensor is installed on the cylinder block or the transaxle housing and generates alternating current by magnetic flux field which is made by the sensor and the target wheel when engine runs. The target wheel consists of 58 slots and 2 missing slots on 360 degrees CA (Crank Angle).

1.Check signal waveform of CKPS and CMPS using a GDS.

Specification : Refer to "Waveform"

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Remove the engine room under cover.(Refer to Engine and Transaxle Assembly - "Engine Room Under Cover")

3.Disconnect the crankshaft position sensor connector (A).

4.Remove the installation bolt (B), and then remove the crankshaft position sensor.

Crankshaft position sensor installation bolt :7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. If the component has been dropped, inspect before installing.

• Apply the engine coolant to the O-ring.

• Insert the sensor in the installation hole and be careful not to damage.

1.Install in the reverse order of removal.

Camshaft Position Sensor (CMPS)

- Description Camshaft Position Sensor (CMPS) is a hall sensor and detects the camshaft position by using a hall element.It is related with Crankshaft Position Sensor (CKPS) and detects the piston position of each cylinder which the CKPS can't detect.The CMPS is installed on engine head cover and uses a target wheel installed on the camshaft. The Cam Position sensor is a hall-effect type sensor. As the target wheel passes the Hall sensor, the magnetic field changes in the sensor. The sensor then switches a signal which creates a square wave.[Bank 1 / Intake]

1.Check signal waveform of CKPS and CMPS using a scan tool.

Specification : Refer to "Waveform"

• DON’T remove the camshaft position sensor during engine running or right after engine stops, or a scald by the flowed out engine oil may occur.

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Disconnect the camshaft position sensor connector (A).

3.Remove the installation bolt, and then remove the sensor (B).

Camshaft position sensor installation bolt :7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Disconnect the camshaft position sensor connector (A).

3.Remove the installation bolt, and then remove the sensor (B).

Camshaft position sensor installation bolt :7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. If the component has been dropped, inspect before installing.

• Apply the engine coolant to the O-ring.

• Insert the sensor in the installation hole and be careful not to damage.

1.Install in the reverse order of removal.

Knock Sensor (KS)

- Description Knocking is a phenomenon characterized by undesirable vibration and noise and can cause engine damage. Knock Sensor (KS) is installed on the cylinder block and senses engine knocking.When knocking occurs, the vibration from the cylinder block is applied as pressure to the piezoelectric element. At this time, this sensor transfers the voltage signal higher than the specified value to the ECM and the ECM retards the ignition timing. If the knocking disappears after retarding the ignition timing, the ECM will advance the ignition timing. This sequential control can improve engine power, torque and fuel economy.

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Remove the intake manifold.(Refer to Engine Mechanical System - "Intake Manifold")

3.Remove the installation bolt (A), and then remove the sensor from the cylinder block.

Knock sensor installation bolt :18.6 ~ 24.5 N.m (1.9 ~ 2.5 kgf.m, 13.7 ~ 18.1 lb-ft)

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.

1.Install in the reverse order of removal.

Heated Oxygen Sensor (HO2S) ➤

Accelerator Position Sensor (APS)

- Description Accelerator Position Sensor (APS) is installed on the accelerator pedal module and detects the rotation angle of the accelerator pedal. The APS is one of the most important sensors in engine control system, so it consists of the two sensors which adapt individual sensor power and ground line. The second sensor monitors the first sensor and its output voltage is half of the first one. If the ratio of the sensor 1 and 2 is out of the range (approximately 1/2), the diagnostic system judges that it is abnormal.

1.Connect the GDS on the Diagnosis Link Connector (DLC).

2.Start engine and check output voltages of APS 1 and 2 at C.T and W.O.T.

Specification : Refer to Specification Section.

Fuel Tank Pressure Sensor (FTPS) ➤

Injector ➤

Purge Control Solenoid Valve (PCSV)

- Description Purge Control Solenoid Valve (PCSV) is a solenoid valve and is installed on the surge tank and controls the passage between the canister and the intake manifold.The evaporative gases gathered in the canister are delivered to the intake manifold when the PCSV is open by ECM control signal.

1.Turn ignition switch OFF.

2.Disconnect PCSV connector.

3.Measure resistance between PCSV terminals 1 and 2.

4.Check that the resistance is within the specification.

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Disconnect the purge control solenoid valve connector (A).

3.Disconnect the vapor hoses (B).

4.Remove the purge control solenoid valve (C).

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.

• Be careful of foreign material not to flow into the valve.

1.Install in the reverse order of removal.

CVVT Oil Control Valve (OCV)

- Description The Continuously Variable Valve Timing (CVVT) system controls the amount of valve overlap by varying the amount of oil flow into an assembly mounted on the intake camshaft through ECM control of an oil control valve.As oil is directed into the chambers of the CVVT assembly, the cam phase is changed to suit various performance and emissions requirements.

1.When camshaft rotates engine rotation-wise: Intake-Advance / Exhaust-Retard

2.When camshaft rotates counter engine rotation-wise: Intake- Retard / Exhaust- Advance

1.Turn ignition switch OFF.

2.Disconnect OCV connector.

3.Measure resistance between OCV terminals 1 and 2.

4.Check that the resistance is within the specification.

Specification : Refer to "Specification"

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Remove the cylinder head cover.(Refer to Engine Mechanical System - "Cylinder Head Cover")

3.When reomve the oil control valve, hold the hexagonal portion on the camshaft with a wrench to prevent the camshaft from rotating.

4.Remove the CVVT oil control valve (A).[Bank 1 / Intake]

1.Install in the reverse order of removal.

Variable Force Solenoid (VFS) ➤

Variable Intake Solenoid (VIS) Valve ➤

Electric EGR Control Valve ➤

Canister Close Valve (CCV)

- Description Fuel Tank Pressure Sensor (FTPS) is a component of the evaporative emission control system and is installed on the fuel tank, the fuel pump, or the canister. It checks the purge control solenoid valve operation and detects a leakage of the system.

1.Turn the ignition switch OFF.

2.Disconnect the CCV connector.

3.Measure resistance between the CCV terminal 1 and 2.

4.Check that the resistance is within the specification.

Specification : Refer to "Specification"

5.Disconnect the vapor hose connected with the canister from the CCV.

6.Connect a vacuum pump to the nipple.

7.Ground the CCV control line and apply battery voltage to the CCV power supply line.

8.Apply vacuum and check the valve operation.

Specification : Vacuum maintained

1.Turn the ignition switch OFF and disconnect the battery negative (-) cable.

2.Lift the vehicle.

3.Disconnect the canister close velve extension connector (A).

4.Remove the canister protector (B).

5.Disconnect the canister close velve connector (A).

6.Remove the ventilation hose (B).

7.Remove the air filter (A).

8.Release the lever (A), and then separate the canister close valve (B) from the fuel tank air filter after rotating it in the direction of the arrow in the figure.

• Install the component with the specified torques.

• Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.

1.Install in the reverse order of removal.

Thermal Management Module (TMM) Motor

- Description Integrated Thermal Management Module (ITM) is a device that controls the coolant flow rate according to coolant temperature. At initial startup, the ITM quickly warms up the engine by controlling the flow of the coolant and this fast warm-up helps improve the fuel efficiency. When the coolant temperature rises, the ITM adjusts the cooling water temperature by controlling the valves to regulate the flow of coolant through a radiator or heater.

1. Integrated thermal management module (ITM)
2. Integrated thermal management module (ITM) O-ring
3. Heater pipe B
4. Heater water hose
5. Heater pipe A
6. Heater pipe A gasket
7. Water inlet fitting
8. Water inlet fitting gasket

1.Remove the integrated thermal management module (ITM).(Refer to Engine Mechanical System - "Integrated Thermal Management Module (ITM)")

• A separate replacement of the ITM (Integrated Thermal Management Motor) is not possible. You should place the new ITM (Integrated Thermal Management Module) assembly to fix the problem.

1.Install in the reverse order of removal.

• A separate replacement of the ITM (Integrated Thermal Management Motor) is not possible. You should place the new ITM (Integrated Thermal Management Module) assembly to fix the problem.