Chery Tiggo 5 (T21). Service manual — part 102

06–

250

06

Air Flow Meter

Description

The air flow meter is installed on the air inlet pipe behind air filter, which is used to measure mass of air
passing through.

Operation

When there is no mass flow, the electrical axle maintains a balance. The control circuit outputs a certain
heating current to hot-wire resistance RH. When there is mass flow, the electrical axle is out of balance due to
change of RH resistance (cooling of RH resulting from surrounding air absorbing RH's heat). The current
passing through hot-wire resistance IH must increase to keep hot-wire resistance and temperature difference
of air sucked invariant and at a fixed value. Therefore, hot-wire current IH is function of air mass flow.

Removal & Installation

(

See page 10-13

)

06–

251

06

Ignition Coil

Description

The ignition coil converts the low voltage of primary winding into the high voltage of secondary winding, and
discharges spark plug electrode to produce sparks which will ignite the combustible air-fuel mixture in
cylinder.

Operation

An ignition coil consists of primary winding, secondary winding, iron core and housing etc. The primary and
secondary windings form an induced circuit. An instant induced voltage generated by turning primary circuit
switch on and off and an instant high voltage generated by secondary circuit will cause spark plugs to
discharge, thus igniting the combustible air-fuel mixture. The primary winding will recharge when its ground
passage is on through an Engine Control Module (ECM) signal. If Engine Control Module (ECM) cuts off the
control signal to primary winding circuit, it will stop charging and a high voltage will be induced in the
secondary winding.

Removal & Installation

(

See page 14-10

)

06–

252

06

Electric Fuel Pump

Description

The electric fuel pump consists of DC motor, vane pump and end cover (integrated with check valve, pressure
regulator and anti-electromagnetic interference element) etc. The pump and motor are installed coaxially, and
sealed in the same housing. Fuel is filled around the pump and motor in the housing and used for heat
dissipation and lubrication.

Operation

The battery supplies power to electric fuel pump via electric fuel pump relay, which can turn on electric fuel
pump circuit only when starting and engine running. When engine stops running because of an accident, the
fuel pump stops running automatically. The maximum pressure at electric fuel pump outlet is adjusted by
pressure regulator to keep the whole fuel system pressure at 400 kPa.

Removal & Installation

(

See page 08-14

)

06–

253

06

Fuel Injector

Description

The fuel injector is located on the cylinder head near to intake valve, and the nozzle end is located directly
above the intake port.

Operation

The Engine Control Module (ECM) sends electric pulse to injector coil, forming magnetic field force. When
magnetic field force increases enough to overcome the resultant force from return spring pressure, needle
gravity and friction force, the needle begins to rise up and injector starts to inject fuel. The pressure of return
spring forces the needle to close again when injection pulse stops.

Removal & Installation

(

See page 08-26

)