Chery Tiggo 5 (T21). Service manual — part 100

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SQR484F ENGINE MANAGEMENT SYSTEM

ON-VEHICLE SERVICE

Intake/Exhaust VVT Control Valve

Description

There are two VVT control valves, which are located on intake side and exhaust side respectively.

Operation

ECM controls the VVT control valve depending on the engine condition, changes the flowing direction of oil in
the phasers to advance or retard intake/exhaust camshaft, thus changing the timing of intake valve and
exhaust valve.

Removal

Use the same procedures of removal for exhaust VVT control valve and intake VVT control valve. The
procedures listed below are for the intake VVT control valve.
1. Turn off all electrical equipment and ignition switch.
2. Disconnect negative battery cable.
3. Remove engine trim cover.
4. Remove intake VVT control valve.

a. Disconnect intake VVT control valve connector.

b. Remove intake VVT control valve fixing bolt and

intake VVT control valve.



(Tightening torque: 8 ± 2 N·m)

Installation

Installation is in the reverse order of removal.

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Coolant Temperature Sensor

Description

The coolant temperature sensor is a negative temperature coefficient sensor, which is installed into the
mounting hole in thermostat holder.

Operation

The coolant temperature sensor provides an input signal for Engine Control Module (ECM). As temperature
increases, the resistance of sensor decreases. As coolant temperature changes, resistance of coolant
temperature sensor varies accordingly, resulting in a change in voltage of coolant temperature sensor signal
circuit. The ECM uses input signal to control air-fuel mixture, ignition timing, A/C compressor and radiator fan
on/off timing.

Removal

1. Turn off all electrical equipment and ignition switch.
2. Disconnect negative battery cable.
3. Drain coolant (

See page 12-13

).

4. Remove engine trim cover.
5. Remove coolant temperature sensor.

a. Disconnect coolant temperature sensor connector

and remove coolant temperature sensor.



(Tightening torque: 11 - 16 N·m)

WARNING

 Make sure engine is in low temperature before operating cooling system. Never open the expansion tank

cover and remove the drain cock plug when engine is operating or cooling system is in high temperature.
High-pressurized hot engine coolant and steam may flow out and cause serious injury.

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WARNING

 Remove the coolant temperature sensor when engine cools down to avoid scalding injury.

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Installation

Installation is in the reverse order of removal.

CAUTION

 Perform sealing with anaerobic seal gum.
 Confirm that the sensor is tightened fully during installation.
 After installing engine coolant temperature sensor, add coolant and check coolant level.

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Knock Sensor

Description

The knock sensor is installed on cylinder block, and used to detect engine vibration caused by detonation.

Operation

The sensitive element of knock sensor is a piezoelectric ceramic. Vibration of engine cylinder block is
transferred to the piezoelectric ceramic through a mass block in knock sensor. Due to the pressure generated
by vibration of mass block, the piezoelectric ceramic generates a voltage at both electrode faces, and
converts the vibration signal to an AC voltage signal to output it. As intensity of vibration increases, knock
sensor output voltage increases accordingly.
Because frequency of vibration signal caused by engine knocking is far more than that of normal engine
vibration signal, Engine Control Module (ECM) can distinguish between knock or non-knock signals by
processing these signals from knock sensor.

Removal

1. Turn off all electrical equipment and ignition switch.
2. Disconnect negative battery cable.
3. Remove engine trim cover.
4. Remove knock sensor.

a. Disconnect knock sensor connector, and move away

the knock sensor cable from bracket.

b. Remove intake manifold assembly (

See page 10-24

).

c. Remove knock sensor fixing bolt and knock sensor.



(Tightening torque: 20 ± 5 N·m)

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