Chery A15. Manual — part 257

2. Component parameters:
Valve hole diameter:

Φ38 mm

Idle speed valve hole diameter:

Φ10 mm

3. Fault diagnosis
Tips: All the following judgments are based on the normal operation of the vehicle, wire
harness and other system components.

The valve and idle speed valve hole are partially blocked by oil dirt and shall be

cleaned regularly;

Poor adjustment of the throttle pull rod
Poor adjustment of the throttle limit screws
Throttle scratches or worn-out shaft

Three. Idle speed control valve
1. Functions and principles
The function of idle speed control valve is to control the flow area of the bypass to the
throttle body to adjust the air inflow into the engine and thusly control the engine idle
speed.













空气：Air 怠速控制阀：Idle speed control valve
节流阀体：Throttle body

The main component of the idle speed control valve is one stepping motor. The ECM
controls the advance/backup displacement of the valve by way of numeric square waves.


Wiring terminals: A: coil B –

B: coil B +

C: coil A –

D: coil A +

Fixing: throttle body or air intake manifold
2. Component parameters:
Coil resistance: 53

Ω ±10％

Coil inductance: 33mH

±20％

Working voltage: 7.5～12V
Ultimate voltage: 3.5～14V
3. Fault diagnosis
Tips: All the following judgments are based on the normal operation of the vehicle, wire
harness and other system components.
The faults are discovered by the system and displayed on the diagnostic instrument.

• Blocked valve hole
• Wrong fittings between valve wiring terminals and ECM wiring terminals in the

wire harness;

• Wrong ECM normal power supply

• No initialization of the computer (see the chapter on maintenance).

Section Four. Ignition System

One. General description
1. Functions and principles
The function of the ignition system is to ignite the air and fuel mixture in the engine
cylinder at the right time as per the instructions given by the engine control module.
Grouped ignition is adopted for the system. The engine’s four cylinders are divided into
the two groups of 1-4 and 2-3 which are independently controlled for ignition. The
ignition timing and coil driving are completed by the ECM.











2. Ignition system structure

点火线圈

火花塞引线

火花塞

点火系统

Ignition system
Ignition coil, Spark plug wire, Spark plug

Two. Ignition coil
1. Functions and principles
The ignition coil assembly consists of two coils, each of which provides the ignition
energy for the cylinder spark plugs at 360 degrees of crank angle. The ignition is actuated
when the piston reaches the upper limits of compression and exhaust; as the cylinder near
the exhaust upper limit has low internal pressure and high temperature, only some
ignition energy will penetrate the spark plug electrode, which is called additional ignition;
while the cylinder near the upper limit of compression has an air mixture of relatively
high density and pressure, so bigger ignition energy is needed to ignite the spark plug of
the cylinder. The air mixture is rapidly ignited to give out power. The ignition of this
cylinder is called effective ignition.

Fixing: the ignition coil is fixed above the engine valve chamber cover. Pay attention to
the shielding against wireless interference.


2. Component parameters:
Primary resistance: 0.6

±0.05 Ω

Secondary resistance: 1200

±400 KΩ

Primary inductance: 2.75

±0.25 mH

Secondary inductance: 17.5

±1.2 H

Voltage range: 6～16 V
Primary charging time: 2.55 mS
Primary inductance peak current: 9.5 A
Primary output voltage: 34 kV
Minimum Zener energy：30 mJ
Minimum ignition time: 0.8 mS
Secondary peak current: 97 mA
Wiring terminals: 1 - 2-3 cylinder drive,
2 - +12V, 3 – 1-4 cylinder drive;


2. Fault diagnosis
Tips: All the following judgments are based
on the normal operation of the vehicle, wire
harness and other system components.
The faults are discovered by the system and
displayed on the diagnostic instrument. Spark
plug wire leads are detached.

Three. Spark plug
The function of the spark plug is to ignite the
combustible gas in the engine cylinder;
In order to reduce the wireless interference
and protect the ignition coil drive during
ignition, the spark plug shall be of a resistance
type;
In order to guarantee the energy release from
the ignition coil, the spark plug clearance shall
be adjusted to 1.0 – 1.2mm;