Chery Tiggo T11 LHD. Manual — part 47

Chery T11 Service Manual Electric Injection System

1

Chapter Ⅰ

Electric Fuel Injection System

Chery T11 Service Manual Electric Injection System

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Section ⅠOperating Principle of Key Components

1. Pressure and Intake Temperature Sensor (TEMP)

MT 20 electronic fuel injection system employs
the velocity-density-air metrological method to
detect the air capacity that flow into the engine,
and further accurately control the power output
of the engine. At the same time, this system
applies

the

Intake

Pressure

Cylinder

Detection technology. The intake pressure
sensor is mounted near the air intake of No. 1
cylinder’s intake manifold. There is an
instantaneous pressure drop in the position of
sensor on the moment when the air intake opens.
The value of pressure drop is approximate
1Kpa. The ECU can detect this instantaneous
pressure drop, receive this signal from the
sensor, and then determine the signal of
compression upper dead center after the signal is
analyzed and processed by software.

The Intake Pressure Sensor’s internal pressure
membrane connects with the magnetic core
placed in a coil. The membrane will move
together with the iron core when the intake air
pressure in the intake pipe changes. In this case,
the output voltage of the sensor will also
change. The ECU can convert the output voltage
of sensor to the intake capacity of the engine.
Based on this signal, another signals will be
referred to control the fuel injection volume of
the engine.

The intake temperature sensor element is a
resistor with negative temperature coefficient
(NTC), the resistance value of which will
decrease as the increase of the intake
temperature. The ECU of engine can monitor
the change of intake temperature through its
internal comparison circuit.

Installation: Installed on the No 1 cylinder’s
intake manifold, and the cylinders are detected
based on the instantaneous pressure drop when
the air intake opens.

Absolute pressure/intake temperature sensor for

intake manifold

Circuit Diagram of the absolute pressure/intake

temperature sensor for intake manifold

T11 Intake pressure

/temperature sensor

Chery T11 Service Manual Electric Injection System

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2. Throttle Position Sensor (TPS)

Application: MT20U TPS (Throttle Position)

sensor is available to provide the ECU with the

information about the throttle’s opening angle

and

angular velocity and the idle position of

the engine. Based on the information, ECU can

obtain the engine’s information on load and

operating condition (such as startup, idle,

reverse towing, part load and full load) as well

as acceleration and deceleration. This sensor is a

three-wire sensor. And the ECU detects the

opening of throttle through the monitoring on

the voltage change.

Profile of a throttle position sensor

Troubleshooting:

1) Mainly examine the short or open circuit

between the four wires on sensor and the

ECU.

2) Examine the clog of the sensor’s detection

hole.

3) Examine the short or open circuit and the

grounding among the harnesses of sensor.

4) Examine the sensor’s impact received to

cause the sensor failure.

5) Detection pressure range: 10kPa to 110

kPa

Trouble Diagnosis:

1) Short circuit of the sensor’s wire (shorted to

earth, or shorted to supply);

2) Open circuit of the sensor’s wire;

3) The intake pressure detected by sensor is

greater than its upper limit;

4) The intake pressure detected by sensor is

less than its upper limit;

Pin:

1) No.1 (A) for the signal from intake pressure

sensor (to ECU 42#);

2) No.2 (B) for the standard 5V power supply

(to ECU 4#);

3) No.3 (C) for the signal from the intake

temperature sensor (to ECU 27#);

4) No.4 (D) for the ground wire of sensor (to

ECU 21#).

Operating temperature range: -40℃ to 125℃

Operating Voltage: 5.0V ±0.1V

Chery T11 Service Manual Electric Injection System

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Structure and Principle: This sensor is with
the slip resistance structure (i.e. the linear
variable

resistance

structure).

The

ECU

monitors the voltage among the signal output
terminals and gets the opening signal of the
throttle

through

the

circuits

comparison

conducted inside the computer. In the ECU, the
voltage signal is not received directly but rather
the input-to-output signal ratio is detected,
which can avoid the signal fluctuation generated
due to the voltage fluctuation.

Trouble Diagnosis:

The signal from throttle position sensor is
greater than the measuring range;

The signal from throttle position sensor is less
than the measuring range;

Short circuit of the throttle position sensor
signal connection;

Open circuit of the throttle position sensor
signal connection;

WARNING: It is generally prohibited to
disassemble the throttle position sensor which
has adjusted to its optimal position before it
leaves factory.

Installation: The allowable tightening torque of
the tightening screw is 1.5 Nm to 2.5 Nm.

Troubleshooting:

1) Mainly examine the short or open circuit

between the three wires on sensor and the
ECU.

2) Examine the short or open circuit and the

grounding among the harnesses of sensor.

3) Examine the jump between the sensor

signal terminal and the ground wire, which
is detected with the universal meter.

4) Examine the sensor’s resistance which is

evidently greater than the standard value,
the season of which may be that the interior
of sensor is dirty.

T11 Throttle Position Sensor

Circuit diagram of the throttle position sensor

Pin:

1) No.1 (A) for the standard 5V power supply

(to ECU 20#);

2) No.2 (B) for the ground wire of sensor (to

ECU 5#).

3) No.3 (C) for the signal from the sensor (to

ECU 24#);

Operating Voltage: 5±0.1 V

Opening Range: 7% to 93%

Resistance of Sensor: 3 kΩ to 12 kΩ

Output signal during the close of throttle:

0.612 to 0.588 V

Output signal during the full open of throttle:

4.15 to 4.65 V