Chery Tiggo 5 (T21). 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

)