Chery A15. Manual — part 256

2. Component parameters:
Working temperature: -40 ～ 150℃
Working voltage: 4.5 ～13 V
Working clearance: 0.3 ～ 2 mm
Wiring terminals:
1 – Signal, 2 – signal grounding, 3 - +5V
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.

• Overvoltage damage;
• Over clearance between the sensor and

the signal wheel;

• Incorrect relative position or

displacement of the signal wheel to the
camshaft

Eight. Vehicle speed sensor (VSS)
1. Functions and principles
Vehicle speed signals are provided by the
vehicle speed sensor. ECM receives the digital
square waves whose amplitude is 5 – 14V.
The system demarcation uses the signals to
improve the vehicle driving performance.
Wiring terminals:
1 – 12V power source, 2 – grounding, 3 –
vehicle signal
Fixing: it is fixed behind the gearbox casing.

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.
Signal failure causes includes: sensor damage,
fitting detachment, wire harness fault or other
human factors. The system will accordingly
restrict the vehicle driving component
parameters, or the driving performance will
worsen.


Nine. Knock sensor (KS)
1. Function and principles
Knock sensor is a kind of electronic vibrating
sensor and fixed on a sensitive position on the
engine cylinder body for sensing the knock of
the engine.
ECM can detect the knock intensity through
the knock sensor and then correct the ignition
advance angle to effectively control the knock,
optimize the engine power generation, save
fuel cost and minimize exhaust.
The system uses flat response knock sensor
and the ECM filters the received signals; as
the sensor signal is relatively weak, the wire
lead shall be shielded.
Wiring terminals:

Knock

1 – Signal, 2 – Grounded through the
shielding
Fixing: the knock sensor is fixed onto the
middle of the engine cylinder and below the
air intake manifold.
2. Component parameters:
Output signals:
Vibrating frequency Output signals
5kHz 17～37mV/g
8kHz increase by +15％at 5kHz
13kHz increase by +30％at 5kHz

18kHz double at 13kHz and >17mV/g at
any moment
Frequency range for response: 3 – 18kHz
Capacitance: 1480～2220pf at 25℃, 1000Hz
Resistance: >1M

Ω at 25℃

Working temperature: -40～150℃
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.
The signal cable is not shielded or the shield has ground fault;
Sensor fixing torque is bigger than 200N.m;
Bad gasoline quality;
Faults of engine turning parts (like water pump);
Extra fuel in the engine;
Striking on the engine bracket;
Sensor faults.

Section Three. Air intake Control System

One. General description
1. Functions and principles

• The function of the air intake control system is to provide proper air flow required

by the engine power output. The control of air inflow consists of active control
and system automatic control;

• Active control refers to the driver’s active adjustment of throttle opening and

control of the engine power output as required.

• System automatic control refers to the automatic control of air inflow as per the

feedback from the closed-loop control monitor to stabilize the operation of the
engine (e.g. engine idle speed closed-loop control).

2. System structure

阀体

节气门传感器

怠速控制阀

进气控制系统

(

)

节流阀体

Air inflow control system (throttle)
Valve body

Throttle sensor

Idle speed control valve

Two. Throttle assembly
1. Functions and principles
The throttle assembly is used to control the air inflow into the engine in operation. It is
the fundamental channel through which the driver controls the fuel injection system.
The throttle assembly consists of throttle body, valve, pull rod assembly, throttle position
sensor, idle speed control valve, etc;
Fixing: the throttle body is fixed in front of the air intake manifold.