Chery A18. Manual — part 39

THROTTLE POSITION SENSOR

The sensor, including a potentiometer, the movable part of which is controlled by the throttle
axis. ECU supplies a voltage approx. 5V to the potentiometer when working.

From idling to throttle full open, oil injection process is administrated by parameters gained
from throttle valve opening angle.

ECU identifies whether the throttle is in the open or close position according to the output
voltage and modifies the mixture ratio. When throttle closed, the voltage signal is transferred
to ECU to confirm whether the engine is in idle or fuel cut-off state (differ from engine
speed).

Signals for throttle potentiometer need not adjusting because ECU software can automatically
obtain the idle position (0-950mV) of throttle valve.

Potentiometer is installed directly on throttle body and fixed with a fast snap ring.

1.Connector 2.Resistance Circuit 3.Throttle Body 4.Throttle Valve Axis 5.Seat Snap Ring

A – Ground Signal B – 5V Voltage C – Output Signal

Recovery:

If failure happens, the setting value is calculated through the readings of TDC (top dead
center)/ ESS (engine speed sensor) and absolute pressure sensor.

If there is a failure in the absolute pressure sensor signal, set throttle valve opening angle a
fixed value 50 degree. For the moment, adopting the methods like buffering, idling
adaptability and air fuel ratio adjustment all doesn’t work.. Throttle signal cycle is also
malfunctioned when running automatic transmission.

INTEGRAL AIR PRESSURE/TEMPERATURE SENSOR

Pressure signals are obtained from the voltage of one among four resistors in Wheatstone
bridge marked on a special diaphragm. This diaphragm is compressed and stretched under
the absolute pressure from inside of the manifolds (thus the above resistor is under pressure
too).

Air temperature sensor is a negative factor temperature sensor. So the higher the temperature
is, the lower the resistance and the weaker the pressure signals will be.

When a failure in sensor circuit happens, the air temperature is fixed at 45℃.

Recovery:

When a failure in sensor circuit happens, manifolds pressure value will be estimated
according to the method of data-inserting arithmetic based on the rotate speed and related
throttle valve opening angle in a pressure-recovery recorder Then the value shall be modified
by coolant temperature and the air pressure.

Pins:

1. Grounded

2. Outputs Temperature Signal

3. 5V Power Source

4. Outputs Pressure Signal

ASEEMBLY AND DISASSEMBLY OF INTAKE SYSTEM

Remove accessories around the engine:

1.Loosen fastening clamp, demount air

cleaner and air intake hose.

2.Remove throttle cable and clutch cable.

3.Remove all intake pipes and vacuum

hoses around engine.

4.Put down water hose to discharge

anti-freeze liquid.

5.Disassemble the throttle position sensor/

canister

solenoid/crankshaft

position

sensor/Injection nozzle / knock sensor

and wire plugs on electric components

like fuel pressure switch.

CANISTER SOLENOID AND INTAKE/EXHAUST PIPE

Assembly:

——Fix the solenoid on the intake manifolds

with a semicircular clamp and tighten
two inner bolts.

——Install the solenoid intake pipe between

the activated canister and the solenoid,
then tighten the clamp around the intake
pipe with special tool.

——Install solenoid exhaust pipe between the

throttle body and the solenoid. then
tighten the clamp around the exhaust
pipe with special tool.

OIL-VAPOR SEPARATOR

1.Oil-vapor separator 2. Air cleaner 3.Others---ventilating pipe in crankcase

Working principle:

Main function of the oil-vapor separator is leading gas in crankcase to intake manifolds
through oil-vapor separator, which keeps pressure in crankcase within a certain range and
prevent gas in crankcase from mixing and flowing out. Oil-vapor separator shall separate the
oil vapor mixture passed the crankcase to avoid the oil entering into engine where it will
generate carbon grains that causes engine wear.

Oil-vapor separator assembly, air cleaner and ventilating pipe assembly is showed in fig. A
connect to one interface on the engine valve cover; B connect to another interface on the
engine valve cover; C connect to the crankcase interface; D connect to the intake manifold
interface. Connect the ventilating pipe to the interfaces of oil-vapor separator, air cleaner
by-pass hose and engine valve with spring clamp.

Assembly and disassembly:

Fix three iron-ventilating pipes to the bolts in engine intake manifolds using 4 M8 nuts

with a tightening torque of 10±1Nm.

Maintenance of fuel-vapor separator:

Disassemble it per 5000km and wash it with lead-free gasoline, then blow it to dry.

1

A

B

2

C

D

E